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Chem. Proc., 2021, ECSOC-24

The 24th International Electronic Conference on Synthetic Organic Chemistry

Online | 15 November–15 December 2020

Volume Editors:
Julio A. Seijas, Universidad of Santiago De Compostela, Spain
M. Pilar Vázquez-Tato, Universidad of Santiago De Compostela, Spain

Number of Papers: 143
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Cover Story (view full-size image): Electronic Conference on Synthetic Organic Chemistryis a series of conferences that have been maintained through the internet since 1997. This series is an original initiative by MDPI, later [...] Read more.
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902 KiB  
Abstract
Magnetized Dextrin: Eco-Friendly Effective Nanocatalyst for the Synthesis of Dihydropyrano[2,3-c]pyrazole Derivatives
by Zeinab Amiri-Khamakani, Fereshte Hassanzadeh-Afruzi and Ali Maleki
Chem. Proc. 2021, 3(1), 101; https://doi.org/10.3390/ecsoc-24-08285 - 14 Nov 2020
Cited by 7 | Viewed by 1456
Abstract
Dextrin is a water soluble polysaccharide obtained by hydrolysis of starch and glycogen. This low molecular weight biopolymer with valuable properties such as biodegradability, biocompatibility, good availability, and high reactivity can be an appropriate substance to fabricate the environmentally friendly catalysts. The magnetized [...] Read more.
Dextrin is a water soluble polysaccharide obtained by hydrolysis of starch and glycogen. This low molecular weight biopolymer with valuable properties such as biodegradability, biocompatibility, good availability, and high reactivity can be an appropriate substance to fabricate the environmentally friendly catalysts. The magnetized dextrin was prepared via facile co-precipitation procedure of iron salts in the presences of dextrin under alkaline condition. Then, it was characterized by different conventional analyses. Eventually, the catalytic application of obtained nanocomposite was evaluated for the synthesis dihydropyrano[2,3-c]pyrazole derivatives through multicomponent reaction of hydrazine hydrate, ethyl acetoacetate, aromatic aldehydes, and malononitrile. Biocompatible nanocatalyst, simple procedure, short reaction times, and catalyst reusability after four consecutive runs with negligible decrease in catalytic efficiency are some merits of the presented method. Full article
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136 KiB  
Abstract
Chemical Fingerprinting and Antimicrobial Evaluation of the Methanolic Extract of the Leaves of the Endemic Cuban Plant Coccoloba cowellii 
by Daniel Méndez, Julio C. Escalona, Luc Pieters and Paul Cos
Chem. Proc. 2021, 3(1), 124; https://doi.org/10.3390/ecsoc-24-08289 - 14 Nov 2020
Cited by 1 | Viewed by 1418
Abstract
The genus Coccoloba (Polygonaceae) comprises approximately 150 species of flowering plants. It is native to the tropical and subtropical regions of America, in South America, the Caribbean and Central America. A wide variety of biological activities has been studied for Coccoloba species due [...] Read more.
The genus Coccoloba (Polygonaceae) comprises approximately 150 species of flowering plants. It is native to the tropical and subtropical regions of America, in South America, the Caribbean and Central America. A wide variety of biological activities has been studied for Coccoloba species due to great diversity of metabolites (mainly flavonoids, tannins, terpenoids and volatile oils) and popular uses reported for different ailments like fever, diarrhea, menstrual disturbance, uterine hemorrhages, hemorrhoids and gonorrhea. The methanolic extract of the leaves of C. cowellii, endemic of the Camagüey province of Cuba and critically endangered, was subjected to structural analysis. The obtained HPLC-DAD-QTOF-ESI-MS data were analyzed employing the MS-DIAL software. A dereplication of the ESI-MS data was realized using the feature-based molecular networking (FBMN) analysis method in the Global Natural Products Social Molecular Networking (GNPS) infrastructure, leading to 12 compound hits against the GNPS database. A total of 13 compounds were tentatively identified by means of MS data, together with the interpretation of the observed MS/MS spectra in comparison with those found in the literature. The major compounds were myricetin and quercetin glucuronides and glycosides and epichatechin-3-O-gallate. The total extract presented an antifungal effect against Candida albicans ATCC B59630 (azole-resistant) (IC50 = 2.13 µg/mL) and was not cytotoxic (IC50 > 64.00 µg/mL) in the resazurin MRC-5 SV2 cell viability assay employed. This is the first report related to chemical composition of C. cowellii plant. The research is now focused on determining the secondary metabolites responsible for the antifungal activity of the total extract. Full article

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1657 KiB  
Proceeding Paper
Synthesis of Novel Acylhydrazone-Oxazole Hybrids and Docking Studies of SARS-CoV-2 Main Protease
by Verónica G. García-Ramírez, Abel Suarez-Castro, Ma. Guadalupe Villa-Lopez, Erik Díaz-Cervantes, Luis Chacón-García and Carlos J. Cortes-García
Chem. Proc. 2021, 3(1), 1; https://doi.org/10.3390/ecsoc-24-08329 - 14 Nov 2020
Cited by 4 | Viewed by 1786
Abstract
A novel synthetic strategy to obtain acylhydrazone-oxazole hybrids in three-step reactions in moderate to good yields is reported. The key step reaction consists in a Van Leusen reaction using a bifunctional component of both an aldehyde and a functional group. The target molecules [...] Read more.
A novel synthetic strategy to obtain acylhydrazone-oxazole hybrids in three-step reactions in moderate to good yields is reported. The key step reaction consists in a Van Leusen reaction using a bifunctional component of both an aldehyde and a functional group. The target molecules were evaluated via in-silico by molecular docking with the main protease enzyme of SARS-Cov-2, where two acyl hydralazine-oxazoles yielded good predicted free energy values in comparison to the co-crystalized ligand. Full article
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414 KiB  
Proceeding Paper
Cu.BTC MOF as a Novel and Efficient Catalyst for the Synthesis of 1,8-Dioxo-octa-hydro Xanthene
by Hossein Ghafuri, Fatemeh Ganjali and Peyman Hanifehnejad
Chem. Proc. 2021, 3(1), 2; https://doi.org/10.3390/ecsoc-24-08359 - 14 Nov 2020
Cited by 7 | Viewed by 1582
Abstract
: A copper-based metal-organic framework with 1,3,5-tricarboxylic acid linkers was prepared through a facile hydrothermal method. This MOF has not been used in organic reactions widely. Cu.BTC was employed as an affordable, competent heterogeneous catalyst in 1,8-dioxo-octa-hydro xanthene synthesis. Additionally, the structure, morphology, [...] Read more.
: A copper-based metal-organic framework with 1,3,5-tricarboxylic acid linkers was prepared through a facile hydrothermal method. This MOF has not been used in organic reactions widely. Cu.BTC was employed as an affordable, competent heterogeneous catalyst in 1,8-dioxo-octa-hydro xanthene synthesis. Additionally, the structure, morphology, and porosity of this catalyst were considered. Various techniques such as FE-SEM, BET, EDS, FT-IR, and XRD applied to this aim. As a result, Cu.BTC had a mesoporous structure, an excellent specific surface area, and high purity. Some privileges of using this heterogeneous catalyst in 1,8-dioxo-octa-hydro xanthene synthesis are mild condition, increased activity, ease in separation, and reusability. Additionally, 1,8-dioxo-octa-hydro xanthene was obtained via simple recrystallization. Full article
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301 KiB  
Proceeding Paper
3-(Biphenyl)acrylates by One-Pot Suzuki Cross Coupling–Wittig Olefination Reactions
by Areej Hashim, Vijo Poulose and Thies Thiemann
Chem. Proc. 2021, 3(1), 3; https://doi.org/10.3390/ecsoc-24-08350 - 14 Nov 2020
Viewed by 1363
Abstract
3-(Biphenyl)acrylates are prepared in good yield by one-pot Suzuki cross-coupling (Wittig olefination reactions). The central building blocks are 4-formyl- and 3-formylphenylboronic acids and the stabilized (carbomethoxymethylene)triphenylphosphorane. Examples of one-pot Suzuki–double Wittig combinations are also shown. Full article
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350 KiB  
Proceeding Paper
Synthesis of Peptidomimetics via IMCR/Post-Transformation Strategy
by Sandra C. Ramírez-López, Manuel Alejandro Rentería-Gómez, Cesar R. Solorio Alvarado and Rocío Gámez-Montaño
Chem. Proc. 2021, 3(1), 4; https://doi.org/10.3390/ecsoc-24-08396 - 14 Nov 2020
Cited by 2 | Viewed by 1071
Abstract
A series of three 2,5-Diketopiperazine (DKPs) were synthesized via one-pot process through the post- isocyanide-based multicomponent reactions (IMCR)-transformation strategy. This strategy emphasizes the role of orthogonal bifunctional reagents in the IMCR process to increase their synthetic potential, allowing us accessing a synthetic platform [...] Read more.
A series of three 2,5-Diketopiperazine (DKPs) were synthesized via one-pot process through the post- isocyanide-based multicomponent reactions (IMCR)-transformation strategy. This strategy emphasizes the role of orthogonal bifunctional reagents in the IMCR process to increase their synthetic potential, allowing us accessing a synthetic platform from which it is possible to obtain privileged heterocyclic peptidomimetics via lactamization reaction. Full article
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1501 KiB  
Proceeding Paper
Crown Ether Benzoxazolyl-Alanines as Fluorimetric Chemosensors for the Detection of Palladium in Aqueous Environment
by Cátia D. F. Martins, Patrícia M. R. Batista, M. Manuela M. Raposo and Susana P. G. Costa
Chem. Proc. 2021, 3(1), 5; https://doi.org/10.3390/ecsoc-24-08310 - 14 Nov 2020
Viewed by 1027
Abstract
Palladium has wide application in different contexts and, as a consequence, high levels of palladium in the environment have been reported, representing a risk to human health. Considering the interest to develop more selective and sensitive chemosensors for this analyte, two novel benzoxazolyl-alanine [...] Read more.
Palladium has wide application in different contexts and, as a consequence, high levels of palladium in the environment have been reported, representing a risk to human health. Considering the interest to develop more selective and sensitive chemosensors for this analyte, two novel benzoxazolyl-alanine derivatives bearing a crown ether moiety were studied as potential fluorimetric chemosensors for palladium detection. Preliminary chemosensory studies for these unnatural amino acids in the presence of selected metal cations were performed in acetonitrile solution and in aqueous mixtures of sodium dodecyl sulfate (SDS, 20 mM, pH 7.5) solution with acetonitrile, 90:10 v/v. In acetonitrile solution, these probes had a fluorescence response for different cations but, most importantly, in SDS aqueous solution both compounds displayed a selective fluorescence response in the presence of palladium. Full article
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407 KiB  
Proceeding Paper
A New Fluorogenic Substrate for Granzyme B Based on Fluorescence Resonance Energy Transfer
by Cátia D. F. Martins, M. Manuela M. Raposo and Susana P. G. Costa
Chem. Proc. 2021, 3(1), 6; https://doi.org/10.3390/ecsoc-24-08311 - 14 Nov 2020
Viewed by 1340
Abstract
The synthesis and characterization of a new fluorogenic substrate for granzyme B (GzmB) is reported. The substrate design was based on the fluorescence resonance energy transfer (FRET) principle using 5-(2′-aminoethyl)aminonaphthalene sulfonic acid (Edans) and 4-[[4′-(N,N-dimethylamino)phenyl]diazenyl]benzoic acid (Dabcyl) as a [...] Read more.
The synthesis and characterization of a new fluorogenic substrate for granzyme B (GzmB) is reported. The substrate design was based on the fluorescence resonance energy transfer (FRET) principle using 5-(2′-aminoethyl)aminonaphthalene sulfonic acid (Edans) and 4-[[4′-(N,N-dimethylamino)phenyl]diazenyl]benzoic acid (Dabcyl) as a donor–acceptor pair, linked to a specific sequence for GzmB (AAD), with an additional amino acid as the anchoring point (K). The tetrapeptide was synthesized by microwave-assisted solid-phase peptide synthesis (MW-SPPS) and coupled to Dabcyl and Edans at its N- and C-termini, respectively. The obtained probe was purified by semi-preparative HPLC and characterized by NMR, UV/Vis absorption and fluorescence spectroscopy and mass spectrometry. Full article
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1242 KiB  
Proceeding Paper
A First Attempt to Identify Repurposable Drugs for Type 2 Diabetes: 3D-Similarity Search and Molecular Docking
by Daniela Istrate, Alina Bora and Luminita Crisan
Chem. Proc. 2021, 3(1), 7; https://doi.org/10.3390/ecsoc-24-08368 - 14 Nov 2020
Viewed by 1532
Abstract
Drug repositioning involves the investigation of existing drugs for new therapeutic purposes, such as type 2 diabetes. This disease affects the health and quality of life for individuals around the world. Sitagliptin, a highly selective dipeptidyl peptidase-4 (DPP-4) inhibitor, is used to treat [...] Read more.
Drug repositioning involves the investigation of existing drugs for new therapeutic purposes, such as type 2 diabetes. This disease affects the health and quality of life for individuals around the world. Sitagliptin, a highly selective dipeptidyl peptidase-4 (DPP-4) inhibitor, is used to treat type 2 diabetes mellitus by effective fasting and improved glycemic control. Despite this advantage, serious hypersensitivity reactions have been acknowledged for patients receiving sitagliptin. In this context, it is necessary to develop new drugs with enhanced profiles and targeting DPP-4. Sitagliptin, ((2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihidro[1,2,4]triazolo[4,3-A]pirazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine), was used as a query in a 3D-similarity search on the approved DrugBank. Based on the TanimotoCombo parameter, the first 10 approved DrugBank drugs were docked in the 4FFW active site to identify effective antidiabetic effects for possible repurposable drugs marketed with other indications. Full article
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1777 KiB  
Proceeding Paper
In Silico Studies on Acetylcholine Receptor Subunit Alpha-L1 for Proposal of Novel Insecticides against Aphis craccivora
by Ana Borota, Luminita Crisan, Alina Bora and Simona Funar-Timofei
Chem. Proc. 2021, 3(1), 8; https://doi.org/10.3390/ecsoc-24-08366 - 14 Nov 2020
Viewed by 1077
Abstract
: Aphis craccivora is an aphid which damages many species of plants and is also a vector for numerous plant viruses. Since neonicotinoids are a well-known class of effective insecticides with less toxicity against mammals and other vertebrates, a small dataset of compounds [...] Read more.
: Aphis craccivora is an aphid which damages many species of plants and is also a vector for numerous plant viruses. Since neonicotinoids are a well-known class of effective insecticides with less toxicity against mammals and other vertebrates, a small dataset of compounds retrieved from the literature based on similarity to highly active neonicotinoids was used. Thus, homology modeling was involved in the building of the 3D structure of the acetylcholine receptor subunit alpha-L1 of Aphis craccivora. The homology model was involved in virtual screening experiments using the FRED docking tool of the OpenEye software. The aforementioned dataset was used to explore the intermolecular ligand–target interaction patterns for a rational design of desired and relatively safe insecticides. Full article
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624 KiB  
Proceeding Paper
Interactions of Alkyl Gallates with SARS-CoV-2 Main Protease: A Molecular Docking Approach
by Amalia Stefaniu, Lucia Pintilie, Bujor Albu and Lucia Pirvu
Chem. Proc. 2021, 3(1), 9; https://doi.org/10.3390/ecsoc-24-08360 - 14 Nov 2020
Viewed by 1121
Abstract
Ten natural and semi-synthetic compounds (gallic acid and alkyl gallates) were investigated by in silico methods in order to evaluate their potential inhibitory activity against SAR-CoV-2 using the X-ray structure of SARS-CoV-2 main protease bound to Boceprevir at 1.45 Å (PDB ID: 6WNP). [...] Read more.
Ten natural and semi-synthetic compounds (gallic acid and alkyl gallates) were investigated by in silico methods in order to evaluate their potential inhibitory activity against SAR-CoV-2 using the X-ray structure of SARS-CoV-2 main protease bound to Boceprevir at 1.45 Å (PDB ID: 6WNP). The evaluation of drug-likeness in terms of Lipinski’s Rule of Five and docking results in terms of docking score and interactions with the amino acids residues from the active binding site of the target protein were reported. Full article
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1180 KiB  
Proceeding Paper
An In Silico Approach to Enzymatic Synthesis of Fucooligosaccharides Using α-l-Fucosidase from Thermotoga maritima
by Emmanuel Pérez-Escalante, Luis Guillermo González-Olivares, Araceli Castañeda-Ovando, Alma Elizabeth Cruz-Guerrero, John F. Trant, Wendolyne López-Orozco, Luis Humberto Mendoza-Huizar and Sergio Alatorre-Santamaría
Chem. Proc. 2021, 3(1), 10; https://doi.org/10.3390/ecsoc-24-08303 - 14 Nov 2020
Cited by 1 | Viewed by 1386
Abstract
Fucooligosaccharides comprise the primary group of human milk oligosaccharides. Due to their beneficial properties, a series of synthetic methods have been proposed to obtain them. Enzymatic methods show great promise, and α-l-fucosidase from Thermotoga maritima has emerged as a powerful catalyst [...] Read more.
Fucooligosaccharides comprise the primary group of human milk oligosaccharides. Due to their beneficial properties, a series of synthetic methods have been proposed to obtain them. Enzymatic methods show great promise, and α-l-fucosidase from Thermotoga maritima has emerged as a powerful catalyst for their production. Nonetheless, the enzyme’s limited substrate scope has delayed its wider application. The present work aims to compare the relative reactivity of fucose, pNP-fucose, and ethyl-fucose, while also exploring the molecular interactions of these fucosyl-donors with the enzyme through a combination DFT and docking analysis. The HOMO-LUMO band gaps range from −7.14571 to −4.24429 eV, with α/β-pNP-fucose and α-fucose being the three most reactive compounds. Moderate association energies between −6.4 to −5.5 kcal·mol−1 were found in the docking analysis, with α-pNP-fucose and both anomers of ethyl-fucose demonstrating the poorest affinity. In the case of α/β-lactose affinity to the β-fucose/enzyme complex, no significant differences were shown. We conclude that the best fucosyl-donors for transfucosylation are those that maintain an enzyme affinity and reactivity similar to pNP-fucose. Full article
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480 KiB  
Proceeding Paper
Design, Synthesis, and Photophysical Properties of BODIPY-Labeled Lupane Triterpenoids
by Rinat Gubaidullin, Darya Nedopekina, Adis Tukhbatullin, Eldar Davletshin and Anna Spivak
Chem. Proc. 2021, 3(1), 11; https://doi.org/10.3390/ecsoc-24-08102 - 13 Nov 2020
Cited by 1 | Viewed by 1377
Abstract
Novel boron-dipyrromethene difluoride (4,4-difluoro-4-bora-3α,4α-diaza-s-indacene) (BODIPY)-lupane triterpenoid conjugates bearing a fluorescent marker at the C-2 position of ring A of the triterpene core were obtained via the Sonogashira reaction as a key step. The starting compounds in the cross-coupling reaction were C-2 propynyl derivatives [...] Read more.
Novel boron-dipyrromethene difluoride (4,4-difluoro-4-bora-3α,4α-diaza-s-indacene) (BODIPY)-lupane triterpenoid conjugates bearing a fluorescent marker at the C-2 position of ring A of the triterpene core were obtained via the Sonogashira reaction as a key step. The starting compounds in the cross-coupling reaction were C-2 propynyl derivatives of betulinic or betulonic acids and fluorescent dyes with an iodo-group at C-2 or meso position of BODIPY-platform. The newly elaborated coupling procedure might have applicability in the synthesis of fluorescently-labeled triterpenoid conjugates suitable for biological assays. Full article
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623 KiB  
Proceeding Paper
Evaluation of Reactivity (pKa) of Substituted Aromatic Diamines, Monomers for Polyamides Synthesis, via Nuclear Magnetic Resonance, NMR-1H
by Juan Enrique Tacoronte Morales, María Teresa Cabrera Pedroso, Joseph Cruel Siguenza and Carla Bernal Villavicencio
Chem. Proc. 2021, 3(1), 12; https://doi.org/10.3390/ecsoc-24-08436 - 14 Nov 2020
Cited by 1 | Viewed by 1529
Abstract
The relationship between properties of aromatic polyamides and the structure and pKa of substituted diamine monomers allows for modeling and designing the synthesis of polymers with special properties for different uses (dialysis membranes, ion exchange systems, to thermo-resistant materials and impact protection devices). [...] Read more.
The relationship between properties of aromatic polyamides and the structure and pKa of substituted diamine monomers allows for modeling and designing the synthesis of polymers with special properties for different uses (dialysis membranes, ion exchange systems, to thermo-resistant materials and impact protection devices). Nuclear Magnetic Resonance is a versatile analytical tool for such purposes. Based on the obtained equations (pKa = 13.1512 − 1.67039 × (ppm)), and chemical shift (, ppm) = −7.0593 − (37.57628 × φ) the reactivity of the monomers can be calculated and selectively modify some properties of polyamides. Aromatic diamines were synthetized according to established protocols and statistical-molecular studies were developed using Hyperchem pack-2005 and Mopac-6. Full article
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1004 KiB  
Proceeding Paper
6-Amino-4-Aryl-3-Carbamoyl-5-Cyano-1,4-Dihydropyridine-2-Thiolates: Synthesis, Reactions and Docking Studies
by Nawras T. Jassim, Victor V. Dotsenko and Nicolai A. Aksenov
Chem. Proc. 2021, 3(1), 13; https://doi.org/10.3390/ecsoc-24-08394 - 14 Nov 2020
Viewed by 1139
Abstract
New triethylammonium 6-amino-4-aryl-3-carbamoyl-5-cyano-1,4-dihydropyridine-2-thiolates were prepared in good yields by the ternary condensation of malononitrile, aldehydes and monothiomalonamide in the presence of Et3N. The thiolates underwent S-alkylation under mild conditions to produce new 1,4-dihydronicotinamides. Molecular docking studies were carried out in order [...] Read more.
New triethylammonium 6-amino-4-aryl-3-carbamoyl-5-cyano-1,4-dihydropyridine-2-thiolates were prepared in good yields by the ternary condensation of malononitrile, aldehydes and monothiomalonamide in the presence of Et3N. The thiolates underwent S-alkylation under mild conditions to produce new 1,4-dihydronicotinamides. Molecular docking studies were carried out in order to explore the interaction mechanism and to investigate suitable binding modes of the new compounds on the calcium channel proteins. Some of the compounds in the in silico experiments were found to be more potent as calcium channel blockers than the reference drug, Nifedipine. Full article
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330 KiB  
Proceeding Paper
New Quinoxaline-1,4-Dioxides Derived from Beirut Reaction of Benzofuroxane with Active Methylene Nitriles
by Victor V. Dotsenko, Karina V. Khalatyan, Alena A. Russkih and Aminat M. Semenova
Chem. Proc. 2021, 3(1), 14; https://doi.org/10.3390/ecsoc-24-08391 - 14 Nov 2020
Viewed by 1129
Abstract
Benzofuroxane reacts under Beirut reaction conditions with active methylene nitriles to give new 2-aminoquinoxaline-1,4-dioxides. The treatment of known 2-amino-3-cyanoquinoxaline-1,4-dioxide with chloroacetyl chloride afforded corresponding chloroacetamide which is useful for the preparation of various heterocycles bearing a quinoxaline-1,4-dioxide core system. Full article
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667 KiB  
Proceeding Paper
Alkynyl N-BODIPYs as Reactive Intermediates for the Development of Dyes for Biophotonics
by César Ray, Andrés García-Sampedro, Christopher Schad, Edurne Avellanal-Zaballa, Florencio Moreno, María J. Ortiz, Jorge Bañuelos, Angeles Villanueva, Pilar Acedo, Beatriz L. Maroto and Santiago de la Moya
Chem. Proc. 2021, 3(1), 15; https://doi.org/10.3390/ecsoc-24-08374 - 14 Nov 2020
Viewed by 1109
Abstract
A new approach for the rapid multi-functionalization of BODIPY dyes towards biophotonics is reported. It is based on novel N-BODIPYs, through reactive intermediates with alkynyl groups to be further derivatized by click chemistry. This approach has been exemplified by the development [...] Read more.
A new approach for the rapid multi-functionalization of BODIPY dyes towards biophotonics is reported. It is based on novel N-BODIPYs, through reactive intermediates with alkynyl groups to be further derivatized by click chemistry. This approach has been exemplified by the development of new dyes for cell bio-imaging, which have proven to successfully internalize into pancreatic cancer cells and accumulate in the mitochondria. The in vitro suitability for photodynamic therapy (PDT) was also analyzed and confirmed our compounds to be promising PDT candidates for the treatment of pancreatic cancer. Full article
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1272 KiB  
Proceeding Paper
1′-Homocarbocyclic Nucleoside Analogs with an Optically Active Substituted Bicyclo[2.2.1]Heptane Scaffold
by Constantin I. Tănase, Constantin Drăghici, Anamaria Hanganu, Lucia Pintilie, Maria Maganu, Vladimir V. Zarubaev, Alexandrina Volobueva and Ekaterina Sinegubova
Chem. Proc. 2021, 3(1), 16; https://doi.org/10.3390/ecsoc-24-08367 - 14 Nov 2020
Viewed by 985
Abstract
An optically active bicyclo[2.2.0]heptane fragment was introduced in the molecule of new 1′-homonucleosides on a 2- 6-chloro-amino-purine scaffold to obtain 6-substituted carbocyclicnucleozide analogs as antiviral compounds. The synthesis was realized by a Mitsunobu reaction of the base with the corresponding bicyclo[2.2.0]heptane intermediate, and [...] Read more.
An optically active bicyclo[2.2.0]heptane fragment was introduced in the molecule of new 1′-homonucleosides on a 2- 6-chloro-amino-purine scaffold to obtain 6-substituted carbocyclicnucleozide analogs as antiviral compounds. The synthesis was realized by a Mitsunobu reaction of the base with the corresponding bicyclo[2.2.0]heptane intermediate, and then the nucleoside analogs were obtained by substitution of the 6-chlorime with selected pharmaceutically accepted amines. A molecular docking study of the compounds on influenza, HSV and low active coronavirus was realized. Experimental screening of the compounds on the same viruses is being developed and soon will be finished. Full article
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425 KiB  
Proceeding Paper
Sustainable Synthesis of Polymeric Materials versus Fine Chemicals via CO2 Addition to Epoxides
by Andreia C. S. Gonzalez, Rafael T. Aroso, Rui M. B. Carrilho, Carmen Claver, Anna M. Masdeu-Bultó and Mariette M. Pereira
Chem. Proc. 2021, 3(1), 17; https://doi.org/10.3390/ecsoc-24-08357 - 14 Nov 2020
Cited by 1 | Viewed by 1145
Abstract
The development of efficient chemical processes capable of transforming carbon dioxide (CO2) into value-added products constitutes one of the greatest challenges for the scientific community. In this context, the use of carbon dioxide as a C1 source is a relevant topic [...] Read more.
The development of efficient chemical processes capable of transforming carbon dioxide (CO2) into value-added products constitutes one of the greatest challenges for the scientific community. In this context, the use of carbon dioxide as a C1 source is a relevant topic and, over the last decade, there has been remarkable scientific and technological advances regarding the development of chemical processes for converting CO2 into added value products. We highlight the reaction of CO2 addition to epoxides, from which it is possible to selectively obtain two types of products: cyclic carbonates and polycarbonates, both with relevant applications as fine chemicals and polymeric materials, respectively. Full article
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1375 KiB  
Proceeding Paper
Anionic Low Band Gap-Conjugated Polyelectrolytes as Hole-Transporting Layer in Optoelectronics Devices
by Benedetta Maria Squeo, Wojciech Mróz, Umberto Giovanella and Mariacecilia Pasini
Chem. Proc. 2021, 3(1), 18; https://doi.org/10.3390/ecsoc-24-08406 - 14 Nov 2020
Viewed by 1143
Abstract
In the last years, interfacial engineering has played a critical role in promoting the performance of optoelectronic devices as organic solar cells (OSC) and organic light-emitting diodes (OLEDs) since interfacial layers help to form an ohmic contact between the electrodes and the active [...] Read more.
In the last years, interfacial engineering has played a critical role in promoting the performance of optoelectronic devices as organic solar cells (OSC) and organic light-emitting diodes (OLEDs) since interfacial layers help to form an ohmic contact between the electrodes and the active layers, which is of great importance for charge collection/injection. Conjugated polyelectrolytes (CPEs), which are conjugated polymers bearing side-chain ionic functionalities such as anionic, cationic, or zwitterionic groups, have emerged as a new class of interfacial materials in thin film-based electronic devices thanks to their ability to reduce the barrier between electrode and active layer. In view of this, we designed and synthesized two novel low bandgap anionic copolymers with different anionic pendant groups and different conjugated backbones to obtain hole-transporting layer (HTL) materials as an alternative to commonly used poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). The functional behavior of these copolymers as anode modifiers is herein preliminarily investigated in an OLED prototype. Full article
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345 KiB  
Proceeding Paper
Evaluation of Organophosphate Pesticide Residues in Food Using the Partial Least Squares Method
by Gheorghe Ilia and Simona Funar-Timofei
Chem. Proc. 2021, 3(1), 19; https://doi.org/10.3390/ecsoc-24-08307 - 14 Nov 2020
Viewed by 1112
Abstract
Organophosphorus (OP) chemicals were broadly used as insecticides and in the treatment of human diseases such as malaria mosquitoes, parasitosis, myasthenia, and glaucoma. The OP toxicity is well known. They can cause environmental and health problems and have the possibility to accumulate in [...] Read more.
Organophosphorus (OP) chemicals were broadly used as insecticides and in the treatment of human diseases such as malaria mosquitoes, parasitosis, myasthenia, and glaucoma. The OP toxicity is well known. They can cause environmental and health problems and have the possibility to accumulate in the food chain. The acceptable daily intake (ADI) can be considered as a measure of the effect of pesticide residues in food on human health. In this paper, the partial least squares (PLS) approach is used to evaluate the ADIs (expressed as pADIs) of a series of 46 structurally diverse OPs. OP structures were pre-optimized using the MMFF94s force field, and structural descriptors were calculated for the minimum energy conformers. This dataset was divided into 26 training compounds, and 20 pesticides were included in the prediction set. Several criteria to check the model robustness, overfitting, and the potential outliers in the X and Y space were employed. The PLS results indicated that new experimental toxicological data would be needed for five out of the 46 OPs, to improve their known ADI values, for qualitative and quantitative dietary long-term risk assessments. Full article
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1195 KiB  
Proceeding Paper
Influence of Copper(I) Halides on the Reactivity of Aliphatic Carbodiimides
by Valentina Ferraro and Marco Bortoluzzi
Chem. Proc. 2021, 3(1), 20; https://doi.org/10.3390/ecsoc-24-08096 - 13 Nov 2020
Cited by 1 | Viewed by 1563
Abstract
The influence of copper(I) halides CuX (X = Cl, Br, I) on the electronic structure of N,N′-diisopropylcarbodiimide (DICDI) and N,N′-dicyclohexylcarbodiimide (DCC) was investigated by means of computational DFT (density functional theory) methods. The coordination of the considered [...] Read more.
The influence of copper(I) halides CuX (X = Cl, Br, I) on the electronic structure of N,N′-diisopropylcarbodiimide (DICDI) and N,N′-dicyclohexylcarbodiimide (DCC) was investigated by means of computational DFT (density functional theory) methods. The coordination of the considered carbodiimides occurs by one of the nitrogen atoms, with the formation of linear complexes having a general formula of [CuX(carbodiimide)]. Besides varying the carbon–nitrogen bond lengths, the thermodynamically favourable interaction with Cu(I) reduces the electron density on the carbodiimides and alters the energies of the (NCN)-centred, unoccupied orbitals. A small dependence of these effects on the choice of the halide was observable. The computed Fukui functions suggested negligible interaction of Cu(I) with incoming nucleophiles, and the reactivity of carbodiimides was altered by coordination mainly because of the increased electrophilicity of the {NCN} fragments. Full article
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245 KiB  
Proceeding Paper
New Dibenzofuran Compounds Obtained by Dihydrousnic Acid Hydrogenation
by Aleksandr Filimonov, Olga Luzina and Nariman Salakhutdinov
Chem. Proc. 2021, 3(1), 21; https://doi.org/10.3390/ecsoc-24-08460 - 16 Nov 2020
Viewed by 1296
Abstract
It has been found that usnic acid carbonyl groups can be hydrogenated by the action of H2/Pd(C). Thus, two new dibenzofuran derivatives were synthesized. Full article
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947 KiB  
Proceeding Paper
Identification of Less Harmful Pesticides against Honey Bees: Shape-Based Similarity Analysis
by Luminita Crisan, Ana Borota, Simona Funar-Timofei and Alina Bora
Chem. Proc. 2021, 3(1), 22; https://doi.org/10.3390/ecsoc-24-08342 - 14 Nov 2020
Viewed by 1143
Abstract
The high concentration of pesticide residues existing in vegetation, crops, and various edible products and the prolonged exposure to them can harm human life and contribute to the disappearance of honey bees, and several avian and animal species. The honey bees (Apis mellifera), [...] Read more.
The high concentration of pesticide residues existing in vegetation, crops, and various edible products and the prolonged exposure to them can harm human life and contribute to the disappearance of honey bees, and several avian and animal species. The honey bees (Apis mellifera), which are efficient pollinators in addition to honey producers, are also considered important non-target test species for the terrestrial toxicity assessment of chemicals. In this context, using thiacloprid and acetamiprid as queries, we performed a 3D similarity search to select new potential products with less harmful effects against bees. For a similarity search, a small dataset of 302 compounds with pesticide activity, compiled from the literature, was used. The first 10 compounds were selected and structurally analyzed according to the TanimotoCombo metrics, and compared with each of these two queries, which is known to be effective, easily metabolized, and less toxic for bees. This approach came as a forward step in the research of pesticide ecotoxicological risk assessment for the evaluation of their potential impact on the pollinator insects and the environment. Full article
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263 KiB  
Proceeding Paper
New Reactions of 5-Amino-3-(Cyanomethyl)-1H-Pyrazole-4-Carbonitrile
by Victor V. Dotsenko, Aminat M. Semenova and Nicolai A. Aksenov
Chem. Proc. 2021, 3(1), 23; https://doi.org/10.3390/ecsoc-24-08398 - 14 Nov 2020
Viewed by 1040
Abstract
5-Amino-3-(cyanomethyl)-1H-pyrazole-4-carbonitrile, prepared by reaction of malononitrile dimer with hydrazine, smoothly reacts with chloroacetyl chloride to form 2-chloro-N-(4-cyano-3-(cyanomethyl)-1H-pyrazol-5-yl)acetamide in good yield. The latter easily reacts with 3-cyanopyridine-2-thiolates to give hybrid molecules bearing nicotinonitrile and pyrazole units. Full article
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202 KiB  
Proceeding Paper
Synthesis of New Water-Soluble Bunte Salts Bearing Thieno[2,3-b]Pyridine-3-yl Substituents
by Darya Yu. Lukina, Maksim O. Drazhin, Victor V. Dotsenko, Nicolai A. Aksenov and Inna V. Aksenova
Chem. Proc. 2021, 3(1), 24; https://doi.org/10.3390/ecsoc-24-08397 - 14 Nov 2020
Viewed by 1682
Abstract
Upon treatment with chloroacetyl chloride, 3-aminothieno[2,3-b]pyridines gave the corresponding chloroacetamides. The latter readily react with sodium thiosulphate to afford water soluble S-alkylthiosulphates with pharmacophoric heterocyclic units. Full article
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1199 KiB  
Proceeding Paper
In Silico Study of Some Natural Flavonoids as Potential Agents against COVID-19: Preliminary Results
by Alina Bora, Liliana Pacureanu and Luminita Crisan
Chem. Proc. 2021, 3(1), 25; https://doi.org/10.3390/ecsoc-24-08343 - 14 Nov 2020
Cited by 2 | Viewed by 1420
Abstract
Flavonoids, widely distributed in fruits, vegetables, and medicinal herbs, are compounds with multiple biological benefits to human health from anti-inflammatory, antioxidant, anticancer, antibacterial to antiviral activity. Coronavirus disease 2019 (COVID-19), a serious concern in the world today, is a respiratory tract disease involving [...] Read more.
Flavonoids, widely distributed in fruits, vegetables, and medicinal herbs, are compounds with multiple biological benefits to human health from anti-inflammatory, antioxidant, anticancer, antibacterial to antiviral activity. Coronavirus disease 2019 (COVID-19), a serious concern in the world today, is a respiratory tract disease involving moderate to severe symptoms of pneumonia, with a major incidence in older people and patients having chronic diseases. This emergency health situation led us to evaluate the possible use of natural products to prevent respiratory diseases. The present study aims to report the potential of four natural flavonoids, known to have anti-inflammatory and antiviral activity, as anti-SARS-CoV-2 through their binding on the 6YNQ protein receptor. Molecular docking study with the FRED program was chosen as an appropriate tool to analyze the interaction of natural flavonoids, quercetin, luteolin, galangin, and naringenin, with the SARS-CoV-2 main protease and to rank the conformations through a scoring function to predict their binding affinity. Overall, our preliminary results indicate the potential of the titled natural flavonoids to fight the new coronavirus, COVID-19. Full article
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512 KiB  
Proceeding Paper
The Reactions of N,N′-Diphenyldithiomalonamide with Michael Acceptors
by Anna E. Sinotsko, Victor V. Dotsenko and Nicolai A. Aksenov
Chem. Proc. 2021, 3(1), 26; https://doi.org/10.3390/ecsoc-24-08399 - 14 Nov 2020
Viewed by 921
Abstract
N,N′-diphenyldithiomalonamide (dithiomalondianilide) smoothly reacts with various Michael acceptors to give either stable Michael adducts or products of their further heterocyclization. The structure of the products was confirmed by 2D NMR experiments and X-ray data. The mechanisms of the reactions are discussed. Full article
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232 KiB  
Proceeding Paper
Microwave-Assisted Asinger Synthesis of Thiazolines
by Raúl Eduardo Gordillo-Cruz, Liliana Gonzalez-Reyes, Milton Coporo-Reyes, Nieves Zavala-Segovia, Bernardo A. Frontana-Uribe, Marco A. García-Eleno, M. V. Basavanag Unnamatla and Erick Cuevas-Yañez
Chem. Proc. 2021, 3(1), 27; https://doi.org/10.3390/ecsoc-24-08316 - 14 Nov 2020
Viewed by 1216
Abstract
An array of 2,4-disubstituted thiazolines was obtained through Asinger reaction approach from the straightforward treatment of diverse aldehydes/ketones with 1-mercaptopropan-2-one, in the presence of NH3 assisted by microwave irradiation, displaying similar and sometimes higher yields, as well as shorter reaction times that [...] Read more.
An array of 2,4-disubstituted thiazolines was obtained through Asinger reaction approach from the straightforward treatment of diverse aldehydes/ketones with 1-mercaptopropan-2-one, in the presence of NH3 assisted by microwave irradiation, displaying similar and sometimes higher yields, as well as shorter reaction times that traditional Asinger reaction conditions at room and lower temperatures. Full article
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427 KiB  
Proceeding Paper
Thiomonosaccharide Derivatives from D-Mannose
by Marcos Díaz-Fernández and M. Soledad Pino-González
Chem. Proc. 2021, 3(1), 28; https://doi.org/10.3390/ecsoc-24-08424 - 14 Nov 2020
Viewed by 1228
Abstract
Sulfur-containing monosaccharide derivatives can be highly valuable for obtaining compounds with biological activities. In this work, a synthetic route starting from D-mannose has been designed. After a convenient hydroxyl protection and anomeric carbon functionalization in a cyano group, a new carbohydrate analogue has [...] Read more.
Sulfur-containing monosaccharide derivatives can be highly valuable for obtaining compounds with biological activities. In this work, a synthetic route starting from D-mannose has been designed. After a convenient hydroxyl protection and anomeric carbon functionalization in a cyano group, a new carbohydrate analogue has been obtained with sulfur in the ring. The heteroatoms have been introduced by an SN2 mechanism, with subsequent cyclization. Structural identification has been performed by different spectroscopic techniques. Full article
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885 KiB  
Proceeding Paper
Synthesis and Photophysical Characterization of 2′-Aminochalcones
by Cátia I. C. Esteves, Luís F. B. Fontes, A. Filipa N. Borges, João Rocha, Artur M. S. Silva and Samuel Guieu
Chem. Proc. 2021, 3(1), 29; https://doi.org/10.3390/ecsoc-24-08301 - 14 Nov 2020
Viewed by 1128
Abstract
Chalcones present biological activity and are, therefore, currently studied for their therapeutic potential. They have shown antitumor, anti-inflammatory, antifungal and antibacterial properties. These compounds occur in nature as secondary metabolites of plants and are precursors of flavonoid biosynthesis. Generally, they are not luminescent, [...] Read more.
Chalcones present biological activity and are, therefore, currently studied for their therapeutic potential. They have shown antitumor, anti-inflammatory, antifungal and antibacterial properties. These compounds occur in nature as secondary metabolites of plants and are precursors of flavonoid biosynthesis. Generally, they are not luminescent, but derivatives with some particular patterns of substitution can present fair quantum yields. Excited State Intramolecular Proton Transfer (ESIPT) is a particular case of tautomerization, and some molecules can exhibit ESIPT fluorescence if their structures incorporate an intramolecular hydrogen bonding interaction between a hydrogen donor (-OH or -NH) and a hydrogen acceptor. If the dye is fluorescent, emission from both tautomers may be observed, leading to a dual emission. The chalcones with a strong push–pull character, compounds 2c, 3c and 4c, presented dual emission of keto–enol tautomerism as a consequence of ESIPT. Full article
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298 KiB  
Proceeding Paper
The Aminometylation of 4-(Alkylthio)-6-amino-2-oxo(thioxo)-1,2-dihydropyridine-3,5-dicarbonitriles
by Ekaterina A. Khrapova, Natalya A. Ryzhkova, Victor V. Dotsenko and Nicolai A. Aksenov
Chem. Proc. 2021, 3(1), 30; https://doi.org/10.3390/ecsoc-24-08401 - 14 Nov 2020
Viewed by 930
Abstract
Easily available 2-(bis(alkylthio)methylene)malononitriles react with cyanoacetamide or cyanothioacetamide to give 4-(alkylthio)-6-amino-2-oxo(thioxo)-1,2-dihydropyridine-3,5-dicarbonitriles. Upon treatment with primary amines and/or HCHO, the compounds undergo heterocyclization to afford new pyrido[1,2-a][1,3,5]triazines or ring-condensed 1,3,5,7-tetrazocine derivatives. Full article
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250 KiB  
Proceeding Paper
In Silico Screening of Agonist and Antagonist Natural Compounds from Reported Essential Oils against Bursaphelenchus xylophilus
by Jorge M. S. Faria, Ana Margarida Rodrigues, Pedro Barbosa and Manuel Mota
Chem. Proc. 2021, 3(1), 31; https://doi.org/10.3390/ecsoc-24-08386 - 14 Nov 2020
Cited by 3 | Viewed by 976
Abstract
Chemical control has been the most effective and reliable containment strategy in integrated pest management of pine wilt disease (PWD), caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus. Yet, large spectrum nematicides can be dangerous to human health and the environment. Essential [...] Read more.
Chemical control has been the most effective and reliable containment strategy in integrated pest management of pine wilt disease (PWD), caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus. Yet, large spectrum nematicides can be dangerous to human health and the environment. Essential oils (EOs) are safer sustainable alternatives, being composed of highly active natural compounds. A survey of bibliographic data on the detailed chemical composition and activity of the EOs used against the PWN allowed pinpointing monoterpenes as the main source of structures with agonist or antagonist properties. Transversal EO data treatment can identify potential highly active anti-PWN compounds. Full article
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767 KiB  
Proceeding Paper
Preparation and Hydro-Lipophilic Properties of Novel Fluorinated Benzyl Carbamates of 4-Aminosalicylanilides
by Timotej Jankech, Dominika Pindjakova, Jiri Kos, Milan Hutta and Josef Jampilek
Chem. Proc. 2021, 3(1), 32; https://doi.org/10.3390/ecsoc-24-08094 - 13 Nov 2020
Viewed by 1098
Abstract
A series of seven fluorinated benzyl carbamates of 4-aminosalicylanilides and unsubstituted benzyl [3-hydroxy-4-(phenylcarbamoyl)phenyl]carbamate designed as agents with the expected anticholinesterase and anti-inflammatory activity were prepared and characterized. As lipophilicity significantly influences the biological activity of compounds, the hydro-lipophilic properties of these mono-, di-, [...] Read more.
A series of seven fluorinated benzyl carbamates of 4-aminosalicylanilides and unsubstituted benzyl [3-hydroxy-4-(phenylcarbamoyl)phenyl]carbamate designed as agents with the expected anticholinesterase and anti-inflammatory activity were prepared and characterized. As lipophilicity significantly influences the biological activity of compounds, the hydro-lipophilic properties of these mono-, di-, and tri-substituted carbamates were investigated in this study. All the discussed derivatives of 4-{[(benzyloxy)carbonyl]amino}-2-hydroxybenzoic acid were analyzed using reversed-phase high performance liquid chromatography to measure lipophilicity. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped non-polar C18 stationary reversed-phase column. In the present study, the correlations between the logarithm of the capacity factor k, the logarithm of the distributive parameter D at pH 7.4, and log P/Clog P values calculated in various ways as well as the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed. Full article
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548 KiB  
Proceeding Paper
Comparative Studies of Various NNRTIs in the Active Site of Different HIV-1RT Receptors
by Priyanka Chandra, Swastika Ganguly and Soikata Karmakar
Chem. Proc. 2021, 3(1), 33; https://doi.org/10.3390/ecsoc-24-08313 - 14 Nov 2020
Cited by 1 | Viewed by 1182
Abstract
HIV is one of the most deadly viruses known to humans and causes a disease, known as Acquired Immunodeficiency Syndrome (or, AIDS). There are only a handful of drugs which are totally effective against the virus. This is due to the enzyme reverse [...] Read more.
HIV is one of the most deadly viruses known to humans and causes a disease, known as Acquired Immunodeficiency Syndrome (or, AIDS). There are only a handful of drugs which are totally effective against the virus. This is due to the enzyme reverse transcriptase present within the virus. Due to various mutations in the enzyme, the virus becomes unresponsive towards the drugs. In the present study, docking studies of the standard non-nucleoside reverse transcriptase inhibitors were performed in the non-nucleoside inhibitory binding pocket of reverse transcriptase enzymes of wild type and the resistant strains of HIV-1RT virus with PDB IDs 1RT2, 1KLM, 3BGR, and 1JLB, respectively, by using Autodock version 4.5.6. A comparison of different compounds docked into the active site of various HIV-1RT strains was carried out. The obtained results indicate that most of the compounds docked into the active site of the different receptors, such as 1RT2, 1KLM, 3BGR, and 1JLB, with good docking scores, are comparable to that of the internal standard (TNK 651) of the wild type strain of HIV-1 virus. A comparison was made based on the binding modes of the compounds in the active site of all the four receptors. Full article
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219 KiB  
Proceeding Paper
On the Acylation of 1,6-Diamino-2-oxo-1,2-dihydropyridine-3,5-dicarbonitriles
by Alexandra R. Chikava, Alexei A. Dolganov and Victor V. Dotsenko
Chem. Proc. 2021, 3(1), 34; https://doi.org/10.3390/ecsoc-24-08315 - 14 Nov 2020
Viewed by 988
Abstract
Here, 1,6-diamino-2-oxo-1,2-dihydropyridine-3,5-dicarbonitriles, prepared by the reaction of cyanoacethydrazide with arylmethylene malononitriles, react with 1-cyanoacetyl-3,5-dimethylpyrazole and chloroacetyl chloride to give corresponding cyanoacetamides and chloroacetamides. The reaction with phthalic anhydride proceeds under harsh conditions to give 4,7-dioxo-4,7-dihydropyrido[1′,2′:2,3][1,2,4]triazolo[5,1-a]isoindole- 1,3-dicarbonitriles. Full article
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226 KiB  
Proceeding Paper
Stable Anionic σ-Complexes of Highly Electrophilic Aromatics and C-Nucleophiles: Synthesis and Oxidation
by Alexey Starosotnikov, Maxim Bastrakov and Vladimir Kokorekin
Chem. Proc. 2021, 3(1), 35; https://doi.org/10.3390/ecsoc-24-08437 - 15 Nov 2020
Viewed by 1171
Abstract
Reactions of dinitrobenzoannulated heterocycles (furazan, thiadiazole, selenadiazole, pyridine) with anionic C-nucleophiles (mono- and diketones, nitroalkanes and related compounds) provided stable anionic adducts in high yields. Consecutive oxidation with ammonium cerium (IV) nitrate resulted in re-aromatization with the formation of the corresponding substitution products, [...] Read more.
Reactions of dinitrobenzoannulated heterocycles (furazan, thiadiazole, selenadiazole, pyridine) with anionic C-nucleophiles (mono- and diketones, nitroalkanes and related compounds) provided stable anionic adducts in high yields. Consecutive oxidation with ammonium cerium (IV) nitrate resulted in re-aromatization with the formation of the corresponding substitution products, formally representing C-H-functionalized benzoheterocycles. Full article
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246 KiB  
Proceeding Paper
Synthesis and Insecticidal Activity of O-alkylated Oxirane Eugenol Derivatives
by Maria José G. Fernandes, David M. Pereira, Renato B. Pereira, A. Gil Fortes, Elisabete M. S. Castanheira and M. Sameiro T. Gonçalves
Chem. Proc. 2021, 3(1), 36; https://doi.org/10.3390/ecsoc-24-08335 - 14 Nov 2020
Viewed by 1228
Abstract
The synthesis of three O-alkylated eugenol derivatives, bearing a hydroxypropyl chain and propyl esters, were synthesized and further converted into the corresponding oxiranes. Oxirane derivatives were then evaluated against their effect upon the viability of the insect cell line Sf9 (Spodoptera [...] Read more.
The synthesis of three O-alkylated eugenol derivatives, bearing a hydroxypropyl chain and propyl esters, were synthesized and further converted into the corresponding oxiranes. Oxirane derivatives were then evaluated against their effect upon the viability of the insect cell line Sf9 (Spodoptera frugiperda), in comparison with the starting O-alkylates. The results pointing to their potential as bioinsecticides, with structural changes eliciting significant effects in terms of potency. Full article
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227 KiB  
Proceeding Paper
Carvacrol Derivatives with Potential Insecticidal Activity
by Carolina M. Natal, David M. Pereira, Renato B. Pereira, Maria José G. Fernandes, A. Gil Fortes, Elisabete M. S. Castanheira and M. Sameiro T. Gonçalves
Chem. Proc. 2021, 3(1), 37; https://doi.org/10.3390/ecsoc-24-08334 - 14 Nov 2020
Cited by 1 | Viewed by 1157
Abstract
Three new carvacrol derivatives 13 possessing aliphatic carbon chains with different sizes as hydroxyl group substituents were synthesized in order to evaluate their insecticidal activity against the insect cell line Sf9 (Spodoptera frugiperda). Full article
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193 KiB  
Proceeding Paper
A Study about the Use of Co or Mn-Based Nanocatalysts for Styrene Epoxidation Reaction
by Lucía Rossi-Fernández, Leandro Aguilar, Viviana Dorn and Gabriel Radivoy
Chem. Proc. 2021, 3(1), 38; https://doi.org/10.3390/ecsoc-24-08312 - 14 Nov 2020
Viewed by 915
Abstract
A new catalytic system consisting of Mn or Co nanoparticles supported on different materials (celite, zeolite, activated carbon, CeO2, ZnO, MgO, Nb2O5) have been studied for styrene epoxidation. The catalysts were easily prepared from commercially available starting [...] Read more.
A new catalytic system consisting of Mn or Co nanoparticles supported on different materials (celite, zeolite, activated carbon, CeO2, ZnO, MgO, Nb2O5) have been studied for styrene epoxidation. The catalysts were easily prepared from commercially available starting materials. Reaction conditions were optimized by testing different solvents, reaction temperatures, oxidizing agents, and optimal catalyst loading. CoNPs/MgO and TBHP as a co-oxidant, in refluxing ACN, allowed total conversion to the epoxide with excellent yield and high selectivity. Full article
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445 KiB  
Proceeding Paper
Nanosystems for the Encapsulation and Release of Plant Extracts with Insecticidal Activity
by Ana I. F. Lopes, David M. Pereira, M. Sameiro T. Gonçalves, A. Gil Fortes and Elisabete M. S. Castanheira
Chem. Proc. 2021, 3(1), 39; https://doi.org/10.3390/ecsoc-24-08332 - 14 Nov 2020
Viewed by 1128
Abstract
Encapsulation in suitable nanostructures is a relevant strategy for the preservation and controlled release of bioactive compounds, allowing a safe application. In this work, dichloromethane extracts of Mentha suaveolens Ehrh. and Phytolacca americana L. were encapsulated in chitosan nanostructures and liposomes of soybean [...] Read more.
Encapsulation in suitable nanostructures is a relevant strategy for the preservation and controlled release of bioactive compounds, allowing a safe application. In this work, dichloromethane extracts of Mentha suaveolens Ehrh. and Phytolacca americana L. were encapsulated in chitosan nanostructures and liposomes of soybean lecithin, considering their potential as biopesticides. Liposomes were prepared either by thin film hydration or ethanolic injection methods. For chitosan, the ionic gelation technique was used. The nanosystems were characterized regarding their size and polydispersity. Encapsulation efficiencies of the extracts were determined (being higher than 60%) and the release profiles were measured. Liposomes generally allowed a delayed release of the extracts, while chitosan nanosystems were suitable for a faster and complete release of the potential bioinsecticides. Full article
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737 KiB  
Proceeding Paper
Fluorescent Calix[4]arene-Oxacyclophane Sensor for Transition Metal Cations
by Alexandra I. Costa, Patrícia D. Barata and José V. Prata
Chem. Proc. 2021, 3(1), 40; https://doi.org/10.3390/ecsoc-24-08453 - 16 Nov 2020
Viewed by 1353
Abstract
The sensing behavior of a calix[4]arene-oxacyclophane-carbazole conjugate (1) towards Cu(I) ions was investigated. Contrary to the noteworthy sensitivity and selectivity previously found for Cu(II), the affinity of 1 for Cu(I) cations is much lower. Through fluorescence titration assays, the apparent binding [...] Read more.
The sensing behavior of a calix[4]arene-oxacyclophane-carbazole conjugate (1) towards Cu(I) ions was investigated. Contrary to the noteworthy sensitivity and selectivity previously found for Cu(II), the affinity of 1 for Cu(I) cations is much lower. Through fluorescence titration assays, the apparent binding constants (Ka) for the two ions were determined, showing that an affinity of over thirteen fold was displayed for Cu(II). Two Cu(I) counter-ions were used to determine possible effects on the binding event. It was found that acetate and iodide ions behave similarly, yielding Ka of the same magnitude. Formation of a ground-state supramolecular complex between 1 and Cu(I) ions was not observed on UV-Vis titrations, in contrast to what was previously reported for Cu(II) using the same host. The affinity of 1 for Fe(III), a major biological competitor, was also assessed. The fluorescence of host 1 is quenched by Fe(III) ions although to a lesser extent (32% less efficient than Cu(II)). The study demonstrates that calixarene 1 is able to differentiate copper ions in two common oxidation states using fluorescence techniques, thereby suggesting its application for redox-active centers in biomimetic chemistry. Full article
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415 KiB  
Proceeding Paper
Synthesis and Preliminary Antibacterial Evaluation of A 2,4,5-Tri(hetero)arylimidazole Derivative
by Nuna L. P. Ramos, Rui Oliveira, Susana P. G. Costa and M. Manuela M. Raposo
Chem. Proc. 2021, 3(1), 41; https://doi.org/10.3390/ecsoc-24-08331 - 14 Nov 2020
Cited by 1 | Viewed by 1075
Abstract
The imidazole ring is a planar heterocycle whose derivatives are applied in several scientific areas, such as medicinal, materials and supramolecular chemistry. The presence of the imidazole ring in these structures is the key to the development of new drugs, since it is [...] Read more.
The imidazole ring is a planar heterocycle whose derivatives are applied in several scientific areas, such as medicinal, materials and supramolecular chemistry. The presence of the imidazole ring in these structures is the key to the development of new drugs, since it is ubiquitous in naturally occurring biological structures. Therefore, over the past few decades, several imidazole derivatives have been synthesized and occupy a unique position in the field of medicinal chemistry due to their diverse biological activities. In order to continue the work developed by the research group, we report the synthesis of 2,4,5-tri(hetero)arylimidazole derivatives and their characterization by 1H and 13C nuclear magnetic resonance (NMR) and UV-Vis absorption spectroscopies. As a complement to the characterization of the synthesized 2,4,5-tri(hetero)arylimidazole derivatives, a screening for antibacterial activity showed the inhibition of Staphylococcus aureus proliferation, suggesting antibacterial activity. Therefore, these new compounds have the potential for the development of new drugs. Full article
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1493 KiB  
Proceeding Paper
Stokesia laevis Ethanolic Extract Activity on the Normal and Malignant Murine Cell Line Viability L969 and B16
by Georgeta Neagu, Amalia Stefaniu, Bujor Albu, Iulian Terchescu, Lucia Pintilie and Lucia Camelia Pirvu
Chem. Proc. 2021, 3(1), 42; https://doi.org/10.3390/ecsoc-24-08318 - 14 Nov 2020
Cited by 1 | Viewed by 919
Abstract
: Stokesia laevis (common name Stokes aster) ethanolic extract (Slae26) containing 5 mg GAE/mL extract was investigated to establish cytotoxicity and anti-proliferative effects. The assays were performed on normal murine fibroblast cell line L929 and malignant murine melanoma cell line B16, respectively; for [...] Read more.
: Stokesia laevis (common name Stokes aster) ethanolic extract (Slae26) containing 5 mg GAE/mL extract was investigated to establish cytotoxicity and anti-proliferative effects. The assays were performed on normal murine fibroblast cell line L929 and malignant murine melanoma cell line B16, respectively; for the first time in literature data, potential cytotoxic and anti-proliferative effects of the ethanolic extract from S. laevis on both, normal murine fibroblast cell line L929, and murine melanoma cell line B16 have been proved. The study is supplemented by molecular docking simulations of the major components of Slae26 against human tyrosinase receptor, to evaluate possible melanogenesis inhibition. Full article
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1031 KiB  
Proceeding Paper
Synthesis of Myrtenal through Allylic Oxidation of α-Pinene over a Pd/SeO2/SiO2 Catalyst
by Florencia Antonella Musso, Victoria Soledad Gutiérrez, María Alicia Volpe and María Belén Faraoni
Chem. Proc. 2021, 3(1), 43; https://doi.org/10.3390/ecsoc-24-08382 - 14 Nov 2020
Viewed by 1642
Abstract
SeO2 based samples are tested for the oxidation of α-pinene, in liquid phase employing ethanol as the solvent. Commercial SeO2 was tested under both reflux and under 6 atm O2 pressure. At conversion levels of approximately 40%, the yield to [...] Read more.
SeO2 based samples are tested for the oxidation of α-pinene, in liquid phase employing ethanol as the solvent. Commercial SeO2 was tested under both reflux and under 6 atm O2 pressure. At conversion levels of approximately 40%, the yield to myrtenal was much higher in the latter (34.4%) than in the former case (18.0%) due to the high oxidant species availability. Besides the high yield attained at relatively short reaction time. A palladium promoted selenium dioxide supported catalyst (Pd/SeO2/SiO2) was prepared, characterized, and submitted to the catalytic test. Selenium dioxide (14.4%) was strongly fixed to the silica support. Upon the palladium introduction (0.98%), the reducibility of SeO2 is modified, which originates a selenium species activation towards the allylic oxidation. A 12% conversion level is attained over Pd/SeO2/SiO2 following 8 h of reaction time, employing ethanol as the solvent at 134 °C. The main product is myrtenal, being obtained with a selectivity of 62%. Over oxidation products are not detected. The palladium/selenium dioxide sample is easy to handle with and its recuperation following the reaction in liquid phase is possible. Full article
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422 KiB  
Proceeding Paper
Synthesis of Tetrakis-Tetrazole via a Repetitive MCR
by Sandra C. Ramírez-López, Àngel Rentería-Gómez, Luis E. Cárdenas Galindo and Rocío Gámez-Montaño
Chem. Proc. 2021, 3(1), 44; https://doi.org/10.3390/ecsoc-24-08395 - 14 Nov 2020
Viewed by 991
Abstract
The synthesis of novel and complex molecules of tetrakis-tetrazole was done via a Ugi-azide repetitive reaction from easily accessible starting materials in good yields. The use of orthogonal bifunctional reagents in isocyanide-based multicomponent reactions (IMCR) allowed the synthesis of structurally complex molecules in [...] Read more.
The synthesis of novel and complex molecules of tetrakis-tetrazole was done via a Ugi-azide repetitive reaction from easily accessible starting materials in good yields. The use of orthogonal bifunctional reagents in isocyanide-based multicomponent reactions (IMCR) allowed the synthesis of structurally complex molecules in one pot manner. The molecules herein synthesized could have applications such as use as chelating agents and organocatalysts. Full article
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743 KiB  
Proceeding Paper
Glucose-Based Molecular Rotors as Fluorescent Inhibitors and Probes of Glycogen Phosphorylase
by Konstantinos F. Mavreas, Michael Mamais, Panagiota Papazafiri and Thanasis Gimisis
Chem. Proc. 2021, 3(1), 45; https://doi.org/10.3390/ecsoc-24-08414 - 14 Nov 2020
Cited by 1 | Viewed by 1326
Abstract
In this study, (E)-2-cyano-3-(6-(dimethylamino)naphthalen-2-yl)-N-(β-d-glucopyranosyl)acrylamide, a β-d-glucopyranosyl analogue of the widely used molecular rotor julolidine, was synthesized and studied photochemically. The new compound is a fluorescent inhibitor of rabbit muscle glycogen phosphorylase with properties of a molecular rotor. Fluorescence measurements [...] Read more.
In this study, (E)-2-cyano-3-(6-(dimethylamino)naphthalen-2-yl)-N-(β-d-glucopyranosyl)acrylamide, a β-d-glucopyranosyl analogue of the widely used molecular rotor julolidine, was synthesized and studied photochemically. The new compound is a fluorescent inhibitor of rabbit muscle glycogen phosphorylase with properties of a molecular rotor. Fluorescence measurements in solutions of increasing viscosity determined that the fluorescence intensity increases with the viscosity of the medium, indicating that the new compound exhibits molecular rotor characteristics. Although the compound fluoresces negligibly in an aqueous buffer solution, in the presence of increasing amounts of rabbit muscle glycogen phosphorylase, we observed an increase in fluorescence intensity, which was attributed to the formation of an inhibitor–enzyme complex. In-vitro cellular studies were also undertaken, yielding promising preliminary results for the use of the new compound as a fluorescent probe. Full article
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4150 KiB  
Proceeding Paper
Molecular Docking Studies on Synthetic Therapeutic Agents for COVID-19
by Lucia Pintilie, Constantin Tanase and Ranjan Kumar Mohapatra
Chem. Proc. 2021, 3(1), 46; https://doi.org/10.3390/ecsoc-24-08352 - 14 Nov 2020
Viewed by 1741
Abstract
Coronavirus disease (COVID-19) is an infectious disease caused by coronavirus 2 (SARS-CoV-2) which was detected for the first time in Wuhan China in December 2019. The rapid spread of this highly contagious and pathogenic virus led to the declaration of the pandemic by [...] Read more.
Coronavirus disease (COVID-19) is an infectious disease caused by coronavirus 2 (SARS-CoV-2) which was detected for the first time in Wuhan China in December 2019. The rapid spread of this highly contagious and pathogenic virus led to the declaration of the pandemic by the World Health Organization (WHO) on March 11, 2020. In these conditions, the discovery of new antiviral agents is extremely important. For the development of the anti-SARS-CoV-2 drugs, the fastest way is to find potential molecules from the marketed drugs by molecular docking studies. Full article
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1461 KiB  
Proceeding Paper
Theoretical Study of the Aza˗Wittig Reaction, Me3P=NR (R = Methyl or Phenyl) with Aldehyde Using the DFT and DFT-D Methods (Dispersion Correction)
by Abdelghani Adda and Hayat Sediki
Chem. Proc. 2021, 3(1), 47; https://doi.org/10.3390/ecsoc-24-08349 - 14 Nov 2020
Cited by 1 | Viewed by 1499
Abstract
: The Aza-Wittig reaction plays an important role in organic transformations and has seen considerable development in the construction of cyclic and acyclic compounds in neutral solvents in the absence of catalysts with a high yield of products. Today, the use of iminophosphoranes [...] Read more.
: The Aza-Wittig reaction plays an important role in organic transformations and has seen considerable development in the construction of cyclic and acyclic compounds in neutral solvents in the absence of catalysts with a high yield of products. Today, the use of iminophosphoranes (phosphazenes) has become a powerful tool in organic synthesis strategies directed toward the construction of nitrogenous heterocycles. These can react with carbonyl compounds, an excellent method for the construction of C=N double bonds via intermolecular and intramolecular Aza-Wittig reactions. In this study, we are interested in the theoretical study of the reaction path of the Aza˗Wittig reaction between trimethyl-iminophosphoranes (CH3)3P=NR, R = CH3 or Ph) for the two-substituent methyl and phenyl with acetaldehyde, including continuum solvation. Our calculations were carried out by means of ab initio calculations using DFT (Density Function Theory) with a dispersion correction term using the Grimme method in the program Gaussian09, using the functional B3LYP-GD3BJ with a 6-31G** base. The results obtained allowed us to highlight the mechanisms of the Aza-Wittig reaction in particular after the addition of the term of dispersion correction or van der Waals correction, which provides a new description of this reaction and its chemical path. Full article
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500 KiB  
Proceeding Paper
Towards Greener Mechanosynthesis of Functional Calixarenes
by Clara Silveiro, Vasco D. B. Bonifácio, José V. Prata, Alexandra I. Costa and Patrícia D. Barata
Chem. Proc. 2021, 3(1), 48; https://doi.org/10.3390/ecsoc-24-08405 - 14 Nov 2020
Viewed by 1005
Abstract
The awareness of sustainability led to increasing global demand for processes that use lower energy, produce reduced waste, use fewer organic solvents, and offer improved selectivity. In this context, mechanochemistry re-emerged as a powerful green methodology. The conventional synthesis and functionalization of calixarenes, [...] Read more.
The awareness of sustainability led to increasing global demand for processes that use lower energy, produce reduced waste, use fewer organic solvents, and offer improved selectivity. In this context, mechanochemistry re-emerged as a powerful green methodology. The conventional synthesis and functionalization of calixarenes, both on the upper and lower rim, has been the subject of numerous studies but only a few were reported using a mechanochemical approach. Herein, we present new mechanically assisted key synthetic steps towards a more sustainable route to calix[4]arenes functionalized in the lower rim. Full article
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1442 KiB  
Proceeding Paper
In Silico Study of the Interaction between Casein with Tocopherols: Preliminary Evaluation of Lipophilic Substrate Inclusion on Proteic Matrix
by Vanina A. Guntero, Leandro Gutierrez, María N. Kneeteman and Cristián A. Ferretti
Chem. Proc. 2021, 3(1), 49; https://doi.org/10.3390/ecsoc-24-08345 - 14 Nov 2020
Cited by 1 | Viewed by 1618
Abstract
Bovine casein is a family of milk proteins with hydrophilic and hydrophobic regions that show block distribution within the protein chain. These amphiphilic properties offer great potential as a material for use as a matrix for transporting active materials such as tocopherol. In [...] Read more.
Bovine casein is a family of milk proteins with hydrophilic and hydrophobic regions that show block distribution within the protein chain. These amphiphilic properties offer great potential as a material for use as a matrix for transporting active materials such as tocopherol. In this work, we aimed to evaluate the interaction of α1-casein, the main fraction of casein, with vitamin E by docking calculations. Docking studies were conducted using SwissDock and DockThor servers. Using specific scoring functions based on energy terms, the best protein–ligand binding models were obtained. The observed interactions between vitamin E and amino acid residues consisted of several hydrophobic interactions (e.g., with Tyr119, Ala144, Trp179, Met211, Pro212). A few hydrogen bonds were observed between the phenyl group of vitamin E and the carboxylate group of the glutamic acid residue (e.g., with Glu85, Glu148). In conclusion, the results suggest that there is a major interaction of vitamin E with random coil structure and interaction with segments formed by α-helix and β-sheet. This implies that in random coil segments there is a predominance of hydrophobic domains. Full article
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366 KiB  
Proceeding Paper
A New Approach to 7-Amino-4-oxo-4,5-dihydro-3H-pyrano[2,3-d]pyrimidine-6-carbonitriles
by Dmitry T. Tebiev, Diana D. Guz’, Victor V. Dotsenko, Nicolai A. Aksenov and Inna V. Aksenova
Chem. Proc. 2021, 3(1), 50; https://doi.org/10.3390/ecsoc-24-08105 - 13 Nov 2020
Cited by 1 | Viewed by 920
Abstract
S-alkyl derivatives of thiobarbituric acid easily react with arylmethylene malononitriles in the presence of base to give new 7-amino-4-oxo-4,5-dihydro-3H-pyrano[2,3-d]pyrimidine-6-carbonitriles. The structure of products and the mechanism of formation are discussed. Full article
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853 KiB  
Proceeding Paper
Preparation of Cu4SnS4/CuCo2S4 Nanoparticles Using Combustion Reaction Accelerated by Organic Driving Agents under Microwave Irradiation
by Maede Aghaei, Mina Imani and Azadeh Tadjarodi
Chem. Proc. 2021, 3(1), 51; https://doi.org/10.3390/ecsoc-24-08354 - 14 Nov 2020
Viewed by 1041
Abstract
Copper-based sulfide-rich nanomaterials have recently attracted attention in various applications due to the lack of expense, abundance, and non-toxicity of their constituent elements. As the members of this family, Cu4SnS4 and CuCo2S4 have exhibited good capability in [...] Read more.
Copper-based sulfide-rich nanomaterials have recently attracted attention in various applications due to the lack of expense, abundance, and non-toxicity of their constituent elements. As the members of this family, Cu4SnS4 and CuCo2S4 have exhibited good capability in a stable manner in solar cells, energy storage electrodes, batteries, etc. In this work, through a facile and rapid combustion reaction accelerated by microwave irradiation, Cu4SnS4/CuCo2S4 nanoparticles were prepared. Thiourea was used as a sulphur source and also organic driving agent. The features of the synthesized product were studied using FT-IR, XRD, SEM, and EDX techniques. The FT-IR and XRD results showed the formation of a multi-components structure containing orthorhombic crystalline phase of Cu4SnS4 alongside carrollite CuCo2S4 phase. Full article
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2467 KiB  
Proceeding Paper
Microwave Assisted Synthesis of CoFe2O4 Nanoparticles by Utilizing Organic Promoters and Evaluation of Its Properties
by Rahil Ahmadi, Mina Imani and Azadeh Tadjarodi
Chem. Proc. 2021, 3(1), 52; https://doi.org/10.3390/ecsoc-24-08351 - 14 Nov 2020
Cited by 5 | Viewed by 1529
Abstract
Nano-sized spinel ferrites are highly regarded owing to their special optical, electrical, and magnetic properties. Cobalt ferrite (CoFe2O4) is a nominee of particular interest due to its high saturation magnetization, high coercivity, strong anisotropy, and excellent chemical stability. The [...] Read more.
Nano-sized spinel ferrites are highly regarded owing to their special optical, electrical, and magnetic properties. Cobalt ferrite (CoFe2O4) is a nominee of particular interest due to its high saturation magnetization, high coercivity, strong anisotropy, and excellent chemical stability. The synthesis of these materials with a pure crystalline phase is sometimes limited due to the required high temperatures for their calcination. In this work, we report a one-pot simple synthesis procedure of cobalt ferrite by the auto-combustion under microwave irradiation into a domestic microwave oven with a power of 900 W for 30 min. Glycine and ammonium nitrate were used as organic promoters and metal nitrates as precursors. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersion of X-ray spectrometry (EDX) techniques. The electrochemical properties and capability of the prepared product as a pseudocapacitive material were evaluated using cyclic voltammetry (CV) tests in details. Full article
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116 KiB  
Proceeding Paper
s-Triazine: A Multidisciplinary and International Journey
by Anamika Sharma, Zainab Almarhoon, Rotimi Sheyi, Rakia Abd Alhameed, Beatriz G. de la Torre, Fernando Albericio and Ayman Al-Faham
Chem. Proc. 2021, 3(1), 53; https://doi.org/10.3390/ecsoc-24-08502 - 20 Nov 2020
Viewed by 1224
Abstract
2,4,6-Trichloro-1,3,5-triazine (TCT) offers the unique ability to undergo sequential nucleophilic substitution reactions using regular nucleophiles (first Cl replacement at 0 °C, second at RT, and third at >90 °C), making s-triazine a privileged scaffold-finding application in drug development with an extension towards the [...] Read more.
2,4,6-Trichloro-1,3,5-triazine (TCT) offers the unique ability to undergo sequential nucleophilic substitution reactions using regular nucleophiles (first Cl replacement at 0 °C, second at RT, and third at >90 °C), making s-triazine a privileged scaffold-finding application in drug development with an extension towards the development of new materials. This selective chemical property of TCT fulfills the goal of chemists to control organic structures and make them react in the required conditions for achieving each objective. In this regard, orthogonality and chemoselectivity are two modern organic chemistry concepts which have been exploited in various areas of research, ranging from supramolecular chemistry to organic/bioconjugation chemistry. We have demonstrated the fusion of these two concepts using TCT as “Orthogonal Chemoselectivity” and defined it as discrimination between reactive sites in any order. The usage of azide as one of the nucleophiles modulated the reactivity of the s-triazine core for the last Cl replacement. This allowed us to overcome the barrier of higher temperature (>90 °C) for the last Cl replacement which happened at RT, taking advantage of side chains of Cys, Tyr and Lys in a biological context. In this presentation, we revise the chemistry developed in our laboratories to manipulate the TCT core for application in our medicinal chemistry programs and in bioconjugation. Full article
299 KiB  
Proceeding Paper
Synthesis of 1,2,3-Triazoles from Alkyne-Azide Cycloaddition Catalyzed by a Bio-Reduced Alkynylcopper (I) Complex
by Josué Varela-Palma, Jaime González, Gustavo Lopez-Téllez, M. V. Basavanag Unnamatla, Marco A. García-Eleno and Erick Cuevas-Yañez
Chem. Proc. 2021, 3(1), 54; https://doi.org/10.3390/ecsoc-24-08384 - 14 Nov 2020
Cited by 2 | Viewed by 1439
Abstract
A small library of 1,2,3-triazoles was synthesized from diverse alkynes and azides using catalytic amounts of an alkynylcopper (I) complex, which in turn was prepared from direct treatment of phenylacetylene with a Fehling reagent in the presence of glucose as a reducing agent. [...] Read more.
A small library of 1,2,3-triazoles was synthesized from diverse alkynes and azides using catalytic amounts of an alkynylcopper (I) complex, which in turn was prepared from direct treatment of phenylacetylene with a Fehling reagent in the presence of glucose as a reducing agent. The results suggest that copper-catalyzed azide alkyne cycloaddition (CuAAC) reactions require only 0.5 mg/mmol copper (I) phenylacetylide without any further additives. Full article
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300 KiB  
Proceeding Paper
Synthesis and Leishmanicidal Activity of Molecular Hybrids 1,2,3-Triazole-Chalcones
by Sofía Vanessa Rodríguez-Gutiérrez, Olalla Barreiro-Costa, Christian David Alcívar León and Jorge Heredia-Moya
Chem. Proc. 2021, 3(1), 55; https://doi.org/10.3390/ecsoc-24-08356 - 14 Nov 2020
Cited by 4 | Viewed by 1900
Abstract
Leishmaniasis is a largely neglected infection caused by Leishmania spp. parasites. The first-line treatment, antimoniate meglumine, has a large number of adverse effects, high cost and is prone to resistance development, hence the necessity of new alternatives. We report the synthesis of (2E)-1-[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazol-4-yl]-3-arylprop-2-en-1-one [...] Read more.
Leishmaniasis is a largely neglected infection caused by Leishmania spp. parasites. The first-line treatment, antimoniate meglumine, has a large number of adverse effects, high cost and is prone to resistance development, hence the necessity of new alternatives. We report the synthesis of (2E)-1-[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazol-4-yl]-3-arylprop-2-en-1-one derivatives and the in vitro evaluation of their leishmanicidal activities. A series of 16 compounds were synthesized in three steps starting from p-anisidine with moderate to good yields and their biological activities were evaluated in vitro against Leishmania mexicana promastigotes and RAW 264.7 cells. The synthesis of 1,2,3-triazol and chalcone moieties were made using a cycloaddition with acetylacetone followed by a Claisen-Schmidt condensation using different substituted benzaldehydes. Nine compounds were active against L. mexicana with IC50 between 1.0 and 29.2 µM. Full article
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183 KiB  
Proceeding Paper
Density Functional Theory (DFT) and Thermodynamics Calculations of Amino Acids with Polar Uncharged Side Chains
by Mihaela Brinzei, Amalia Stefaniu, Olga Iulian and Oana Ciocirlan
Chem. Proc. 2021, 3(1), 56; https://doi.org/10.3390/ecsoc-24-08420 - 14 Nov 2020
Cited by 2 | Viewed by 1816
Abstract
The goal of the present work was to evaluate the chemical reactivity of amino acids with polar uncharged side chains (serine, threonine, asparagine and glutamine) using density functional theory (DFT) and thermodynamics modeling by calculating a series of molecular descriptors and properties of [...] Read more.
The goal of the present work was to evaluate the chemical reactivity of amino acids with polar uncharged side chains (serine, threonine, asparagine and glutamine) using density functional theory (DFT) and thermodynamics modeling by calculating a series of molecular descriptors and properties of their optimized geometries. The predictive calculations were achieved with Spartan software from Wavefunction, Inc. Irvine, CA, USA, hybrid algorithm B3LYP (Becke’s three-term functional; Lee, Yang, Parr exchange hybrid) and polarization basis set 6-31G(d,p) for equilibrium geometry at ground state in vacuum and in water, after energy minimization and geometry optimization. Thermodynamic properties (zero-point energy, enthalpy, constant volume heat capacity, entropy and Gibbs energy) for these derivatives were calculated and related to electrochemical ligand behavior. Reduction and oxidation potentials were correlated to their calculated energy levels for molecular orbitals. Full article
332 KiB  
Proceeding Paper
Cycloaddition of Thiourea- and Guanidine-Substituted Furans to Dienophiles: A Comparison of the Environmentally-Friendly Methods
by Luka Barešić, Davor Margetić and Zoran Glasovac
Chem. Proc. 2021, 3(1), 57; https://doi.org/10.3390/ecsoc-24-08380 - 14 Nov 2020
Cited by 3 | Viewed by 1303
Abstract
The cycloaddition strategy was employed in order to obtain a 7-oxanorbornene framework substituted with a guanidine moiety or its precursor functional groups: protected amine or thiourea. In order to optimize the conditions for the cycloaddition, several environmentally-friendly methods—microwave assisted organic synthesis, high pressure [...] Read more.
The cycloaddition strategy was employed in order to obtain a 7-oxanorbornene framework substituted with a guanidine moiety or its precursor functional groups: protected amine or thiourea. In order to optimize the conditions for the cycloaddition, several environmentally-friendly methods—microwave assisted organic synthesis, high pressure synthesis, high speed vibrational milling, and ultrasound assisted synthesis—were employed. The outcomes of the cycloaddition reactions were interpreted in terms of endo/exo selectivity, the conversion of the reactants to the product, and the isolated yields. In general, our results indicated the HP and HSVM approaches as the methods of choice to give good yields and conversions. Full article
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810 KiB  
Proceeding Paper
Study of Organic Radicals Generated upon Naphthoquinone-Hydantoins Reactions in Basic Aqueous Solution
by Enrique Flores, Ernesto Rivera-Avalos, Braulio Rodríguez-Molina, Carlos Frontana, Lluvia López and Denisse de Loera
Chem. Proc. 2021, 3(1), 58; https://doi.org/10.3390/ecsoc-24-08415 - 14 Nov 2020
Viewed by 1282
Abstract
In this work, the synthesis of thiohydantoins from l-amino acids and isothiocyanates was studied, using a high purity method based on the Edman cycle. This process, expected to occur through the Michael addition to a series of 1,4-naphthoquinone derivatives did not lead to [...] Read more.
In this work, the synthesis of thiohydantoins from l-amino acids and isothiocyanates was studied, using a high purity method based on the Edman cycle. This process, expected to occur through the Michael addition to a series of 1,4-naphthoquinone derivatives did not lead to the expected final product, rather leading to a colored mixture of compounds, where EPR spectra showed that some of them presented unpaired electrons, indicating that an electron transfer pathway was also involved in the reaction mixture. Detected organic radicals proved to be stable albeit with the use of different experimental conditions. Voltammetric results indicated that the reactions led to the formation of electroactive species, probably derived by homogeneous electron transfer between the reactive quinone moieties and the oxidizable urea functions within the hydantoin species. Full article
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377 KiB  
Proceeding Paper
A One-Pot Synthesis of Fluoro α-Acylamino Amide-Xanthates via an IMCR-Post Transformation Strategy
by Manuel A. Rentería-Gómez, Tannya R. Ibarra-Rivera and Rocío Gámez-Montaño
Chem. Proc. 2021, 3(1), 59; https://doi.org/10.3390/ecsoc-24-08421 - 14 Nov 2020
Viewed by 1186
Abstract
A series of six novel amide-xanthate products containing several fluorine atoms were prepared in moderate to good yields (40–92%) via an isocyanide-based multicomponent reaction (IMCR) of 5-CR by Ugi-4CR followed by an SN2 sequence in a one-pot manner. The design of [...] Read more.
A series of six novel amide-xanthate products containing several fluorine atoms were prepared in moderate to good yields (40–92%) via an isocyanide-based multicomponent reaction (IMCR) of 5-CR by Ugi-4CR followed by an SN2 sequence in a one-pot manner. The design of molecules with fluorine atoms is of interest in medicinal chemistry and a research line of our interest. The role of fluorine atoms in biological properties is well documented, improving bioavailability, lipophilicity, and metabolic resistance in bioactive molecules. Full article
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1351 KiB  
Proceeding Paper
Facile Microwave-Assisted Preparation of Hetero-Structured CuCo2S4/CuCo2O4 Nanoparticles Using Organic Agent of Thiourea
by Mahdi Bahmani, Mina Imani and Azadeh Tadjarodi
Chem. Proc. 2021, 3(1), 60; https://doi.org/10.3390/ecsoc-24-08347 - 14 Nov 2020
Viewed by 1077
Abstract
Ultra-fast one-put microwave assisted strategy was introduced for the synthesis of hetero-structured CuCo2S4/CuCo2O4 nanoparticles into a domestic microwave oven with the power of 900 W for 20 min. Thiourea as an organic agent was used as [...] Read more.
Ultra-fast one-put microwave assisted strategy was introduced for the synthesis of hetero-structured CuCo2S4/CuCo2O4 nanoparticles into a domestic microwave oven with the power of 900 W for 20 min. Thiourea as an organic agent was used as a sulfur source and driving agent to lead the solvent free combustion reaction to obtain this earth-abundant and low-cost mixed chalcogenide/oxide product. The structural and morphological specifications were studied in details using powder x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT−IR), scanning electron microscopy (SEM), and energy dispersion of x-ray spectrometry (EDX). The employed strategy relatively clarifies a new facile, rapid, and eco-friendly route to produce heterostructured nanocomposites for different functional purposes. Full article
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399 KiB  
Proceeding Paper
Synthesis of Triphenylamine-Imidazo[1,2-a]pyridine via Groebke–Blackburn–Bienaymé Reaction
by Manuel A. Rentería Gómez, Mahanandaiah Kurva and Rocío Gámez-Montaño
Chem. Proc. 2021, 3(1), 61; https://doi.org/10.3390/ecsoc-24-08422 - 14 Nov 2020
Cited by 2 | Viewed by 1417
Abstract
A series of triphenylamine-imidazo[1,2-a]pyridine were synthesized in moderate yields (57–67%) by Groebke–Blackburn–Bienaymé reaction (GBBR) under catalyst and solvent green conditions. The molecules synthesized containing triphenylamine and imidazo[1,2-a]pyridines cores which are considered a privileged cores exhibited fluorescence and medicinal properties. Full article
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227 KiB  
Proceeding Paper
Synthesis of Amino Alcohols from Eugenol and Their Insecticidal Activity against Sf9 Cell Line
by Nuno F. S. Pinto, David M. Pereira, Renato B. Pereira, A. Gil Fortes, Maria José G. Fernandes, Elisabete M. S. Castanheira and M. Sameiro T. Gonçalves
Chem. Proc. 2021, 3(1), 62; https://doi.org/10.3390/ecsoc-24-08337 - 14 Nov 2020
Cited by 2 | Viewed by 1130
Abstract
Eugenol is a major constituent of clove essential oil with interesting biological activity, namely antimicrobial and antioxidant. Structural changes of eugenol are a useful strategy in order to improve biological activity and at the same time obtain new analogues with reduced side effects. [...] Read more.
Eugenol is a major constituent of clove essential oil with interesting biological activity, namely antimicrobial and antioxidant. Structural changes of eugenol are a useful strategy in order to improve biological activity and at the same time obtain new analogues with reduced side effects. In this work, a series of amine nucleophiles were reacted with eugenol epoxide so as to obtain the corresponding amino alcohols, considering their potential as biopesticides. These eugenol amino alcohols were evaluated against insect cells, specifically the Sf9 cell line. Full article
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639 KiB  
Proceeding Paper
Evaluation of Fluorescent Staining Capacity of Two New Nile Blue Analogues
by João C. C. Ferreira, Rui P. C. L. Sousa, Maria João M. F. Sousa and M. Sameiro T. Gonçalves
Chem. Proc. 2021, 3(1), 63; https://doi.org/10.3390/ecsoc-24-08383 - 14 Nov 2020
Viewed by 943
Abstract
Benzophenoxazine fluorophores, including derivatives of Nile Blue, one of the best known in this family of compounds, have been used as histological stains due to their optical properties in the NIR region and stability. Given their potential, the synthesis of two new Nile [...] Read more.
Benzophenoxazine fluorophores, including derivatives of Nile Blue, one of the best known in this family of compounds, have been used as histological stains due to their optical properties in the NIR region and stability. Given their potential, the synthesis of two new Nile Blue derivatives with different substituents on the amines of the positions 5 and 9 was performed, with the introduction of a sulfonamide group in one of the compounds. Photophysical properties of the compounds were evaluated in acidified ethanol and aqueous solution at physiological pH. The fluorescent staining capacity was evaluated by staining Saccharomyces cerevisiae with the compounds, followed by fluorescence microscopy. Full article
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387 KiB  
Proceeding Paper
Design, Synthesis and Bioactivity of Benzimidazole–2–Carbamates as Soil–Borne Anti–Fungal Agents †,‡
by Thuraya Al–Harthy, Abdullah M. Al-Sadi, Wajdi Zoghaib, Ebrahim Saeedian Moghadam, Raphael Stoll and Raid Abdel-Jalil
Chem. Proc. 2021, 3(1), 64; https://doi.org/10.3390/ecsoc-24-08093 - 13 Nov 2020
Cited by 2 | Viewed by 1334
Abstract
The design and synthesis of new, safe and potent molecules to apply against soil-borne pathogens is a critical goal for organic and bio-medicinal chemists. Herein, we designed and synthesized a series of benzimidazole-based carbamate derivatives (7a–f), as soil-borne anti-fungals. The derivatives 7a–f were [...] Read more.
The design and synthesis of new, safe and potent molecules to apply against soil-borne pathogens is a critical goal for organic and bio-medicinal chemists. Herein, we designed and synthesized a series of benzimidazole-based carbamate derivatives (7a–f), as soil-borne anti-fungals. The derivatives 7a–f were all synthesized in multi-step reactions with acceptable yields. The structures of 7a–f were all identified and characterized using 1H-NMR, IR, HRMS, and melting point calculations. The final compounds were tested on five soil-borne pathogens. The results of various bio-assays showed that compounds 7a-3, 7a-2, 7b-2, 7a-1 and 7b-1 significantly affected the growth of Pythium aphanidermatum, a serious pathogen affecting vegetable crops worldwide. Compounds 7a-1 and 7b-1 were the most efficacious, which resulted in a 96% growth inhibition in Pythium at 100 mg L−1. In conclusion, we reported the potent carbamate derivatives as soil-borne anti-fungals, and believe that the synthesis of more derivatives related to the current scaffold would be beneficial. Full article
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383 KiB  
Proceeding Paper
A meso-Triphenylamine-BODIPY Derivative for the Optical Chemosensing of Metal Ions
by Raquel C. R. Gonçalves, Sónia C. S. Pinto, Susana P. G. Costa and M. Manuela M. Raposo
Chem. Proc. 2021, 3(1), 65; https://doi.org/10.3390/ecsoc-24-08291 - 14 Nov 2020
Cited by 5 | Viewed by 1166
Abstract
The design and synthesis of organic molecules for recognition of biologically/environmentally important metal ions has emerged as a highly regarded research field. The BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) core is a versatile signaling molecule that can be fine-tuned with functional groups to create selective [...] Read more.
The design and synthesis of organic molecules for recognition of biologically/environmentally important metal ions has emerged as a highly regarded research field. The BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) core is a versatile signaling molecule that can be fine-tuned with functional groups to create selective binding sites to improve its optical properties. As an extension of the work developed in our research group, we report the synthesis and characterization of a BODIPY functionalized with triphenylamino and a formyl group at the meso and 2-position, respectively, for the highly selective detection of Cu2+ and Fe3+. The preliminary study of the BODIPY derivative as optical chemosensor was carried out in acetonitrile solution in the presence of different cations, and interactions with Cu2+ and Fe3+ induced a perceptible color change. UV-visible titrations showed changes in the absorption spectra upon the addition of three equivalents of each cation, with the appearance of a new absorption band at 693 nm. Full article
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Proceeding Paper
New Heterocyclic Derivatives of Usnic Acid
by Aleksandr Filimonov, Olga Luzina and Nariman Salakhutdinov
Chem. Proc. 2021, 3(1), 66; https://doi.org/10.3390/ecsoc-24-08459 - 16 Nov 2020
Viewed by 1325
Abstract
New heterocyclic derivatives of usnic acid have been obtained by the reaction of bromousnic acid with CS2-based nucleophiles. A series of compounds with dithiolane, 1,3,4-thiadiazine, and thiophene fragments was synthesized. Full article
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Proceeding Paper
Rational Design, Synthesis, and In-Silico Evaluation of Homologous Local Anesthetic Compounds as TASK-1 Channel Blockers
by Lorena Camargo-Ayala, Luis Prent-Peñaloza, Mauricio Bedoya, Margarita Gutiérrez and Wendy González
Chem. Proc. 2021, 3(1), 67; https://doi.org/10.3390/ecsoc-24-08416 - 14 Nov 2020
Viewed by 1664
Abstract
Advances in different technological and scientific fields have led to the development of tools that allow the design of drugs in a rational way, using defined therapeutic targets, and through simulations that offer a molecular view of the ligand–receptor interactions, giving precise information [...] Read more.
Advances in different technological and scientific fields have led to the development of tools that allow the design of drugs in a rational way, using defined therapeutic targets, and through simulations that offer a molecular view of the ligand–receptor interactions, giving precise information for the design and synthesis of new compounds. Ion channels are of great relevance as therapeutic targets since they play roles in different pathologies. Several ion channels are expressed in the atria and constitute a therapeutic target for the treatment of atrial fibrillation (AF), the most common type of arrhythmia and an important risk factor for an increase in cerebrovascular illness. The action potential (AP) of a cardiomyocyte is initiated by the depolarization of the membrane through the inflow of sodium (Na+). The repolarization currents are realized by different potassium (K+) channels. Background currents of TASK-1 channels can also contribute to AP, and TASK-1 channel blockers could become innovative strategies against AF. The compounds used in this study were based on local anesthetic (LAs)-type compounds that have been shown to be TASK-1 channel blockers, such as lidocaine, ropivacaine, and bupivacaine, and that have antiarrhythmic capacity, becoming potentially effective drugs for the treatment of AF. The main objective of this study was, based on the common characteristics of LAs, to propose the synthesis of analogues of LAs and evaluate them in silico as TASK-1 channel blockers. Full article
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Proceeding Paper
Study of 1,2,4-triazole-3(5)-thiol Behavior in Reactions with 1-phenyl-1H-pyrrole-2,5-dione Derivatives and 3-bromodihydrofuran-2(3H)-one and Antimicrobial Activity of Products
by Serhii Holota, Halyna Derkach, Olha Antoniv, Natalia Slyvka, Roman Kutsyk, Andrzej Gzella and Roman Lesyk
Chem. Proc. 2021, 3(1), 68; https://doi.org/10.3390/ecsoc-24-08419 - 14 Nov 2020
Cited by 3 | Viewed by 1558
Abstract
In present work we report our studies of the interaction of 1-phenyl-1H-pyrrole-2,5-dione derivatives (N-arylmaleimides) and 3-bromodihydrofuran-2(3H)-one (α-bromo-γ-butyrolactone) as possible [C2]2+ synthons with 1,2,4-triazole-3(5)-thiole targeting on synthesis of novel 5-substituted thiazolo[3,2-b][1,2,4]triazole-6(5H)-ones. According to [...] Read more.
In present work we report our studies of the interaction of 1-phenyl-1H-pyrrole-2,5-dione derivatives (N-arylmaleimides) and 3-bromodihydrofuran-2(3H)-one (α-bromo-γ-butyrolactone) as possible [C2]2+ synthons with 1,2,4-triazole-3(5)-thiole targeting on synthesis of novel 5-substituted thiazolo[3,2-b][1,2,4]triazole-6(5H)-ones. According to obtained results was establish that in above-mentioned interactions (conditions: convenient heating, range of solvents/reaction time) the thiol-ene click (for N-arylmaleimides) and SN (for α-bromo-γ-butyrolactone) processes take place, but not [2+3]-cyclocondensation reaction. The structure of compounds was studied using 1H, 13C NMR spectroscopy, LC-MS spectrometry, and X-ray analysis. The prescreening of antimicrobial activity for synthesized compounds was performed against Gram-positive and Gram-negative bacteria, as well as yeasts. Full article
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Proceeding Paper
Synthesis and Antioxidant Activity of 2-Amino-5-R-1,3,4-Oxadiazoles with Hindered Phenol Fragments
by Vladimir N. Koshelev, Olga V. Primerova, Stepan V. Vorobyev and Natalya A. Vakhromova
Chem. Proc. 2021, 3(1), 69; https://doi.org/10.3390/ecsoc-24-08407 - 14 Nov 2020
Cited by 1 | Viewed by 1108
Abstract
Compounds with hindered phenolic moiety are known to be effective inhibitors of oxidative processes in different materials; moreover, a number of phenols show a wide spectrum of biological activity. At the same time, five-membered heterocycles exhibit unique properties, including antioxidant activity. One of [...] Read more.
Compounds with hindered phenolic moiety are known to be effective inhibitors of oxidative processes in different materials; moreover, a number of phenols show a wide spectrum of biological activity. At the same time, five-membered heterocycles exhibit unique properties, including antioxidant activity. One of the ways to create new effective antioxidants with a set of useful properties is to combine hindered phenol and a heterocyclic fragment in one molecule. In this work, new 1-acyl-4-R-thiosemicarbazides were obtained during a reaction between 3-(4-hydroxy-3,5-di-tert-butylphenyl)propanoic acid hydrazide and a number of isothiocyanates. 2-Amino-5-R-1,3,4-oxadiazoles were prepared in good yields by heterocyclization of 1-acyl-4-R-thiosemicarbazides in presence of iodoxybenzoic acid and triethylamine. The antioxidant activity of 1,3,4-oxadiazoles was studied in vitro and was found to be higher than that of 4-methyl-2,6-di-tert-butylphenol. Full article
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Proceeding Paper
Direct Arylation-Based Synthesis of Carbazoles Using an Efficient Palladium Nanocatalyst under Microwave Irradiation
by H. Sebastián Steingruber, Pamela Mendioroz, María A. Volpe and Darío C. Gerbino
Chem. Proc. 2021, 3(1), 70; https://doi.org/10.3390/ecsoc-24-08314 - 14 Nov 2020
Viewed by 1300
Abstract
Herein, an eco-friendly palladium-catalyzed tandem reaction for the one-pot synthesis of carbazoles under microwave irradiation is reported. This approach involves an amination and a direct arylation from available and inexpensive anilines and 1,2-dihaloarenes. For the development of this purpose, a novel recoverable palladium [...] Read more.
Herein, an eco-friendly palladium-catalyzed tandem reaction for the one-pot synthesis of carbazoles under microwave irradiation is reported. This approach involves an amination and a direct arylation from available and inexpensive anilines and 1,2-dihaloarenes. For the development of this purpose, a novel recoverable palladium nanocatalyst supported on a green biochar under ligand-free conditions is used. Compared with other existing palladium-based protocols, the present synthetic methodology shows a drastic reduction in reaction times and excellent compatibility with different functional groups, allowing to obtain a small library of carbazoles with high yields and regioselectivity. The novel heterogeneous palladium nanocatalyst can be recycled and reused up to five times without significant loss activity. Full article
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Proceeding Paper
Chemical Synthesis and Hemi-Synthesis of Novel Benzimidazole Derivatives Using Microwave-Assisted Process: Chemical Characterization, Bioactivities and Molecular Docking
by Asmaâ Sameut, Sarah Yasmine Zanndouche, Chaimaa Boumaza, Chaima Dikes and Borhane Eddine Cherif Ziani
Chem. Proc. 2021, 3(1), 71; https://doi.org/10.3390/ecsoc-24-08306 - 14 Nov 2020
Cited by 2 | Viewed by 1789
Abstract
Benzimidazole derivatives represent a class of heterocyclic compounds that exhibit a wide range of pharmaceutical properties. The present study aimed to investigate the in-vitro antioxidant and antimicrobial activities of newly synthesized benzimidazole derivatives. Compound 1b (2-(1H-1,3-benzodiazol-2-yl) phenol) was synthesized by reacting o-phenylenediamine (OPA) [...] Read more.
Benzimidazole derivatives represent a class of heterocyclic compounds that exhibit a wide range of pharmaceutical properties. The present study aimed to investigate the in-vitro antioxidant and antimicrobial activities of newly synthesized benzimidazole derivatives. Compound 1b (2-(1H-1,3-benzodiazol-2-yl) phenol) was synthesized by reacting o-phenylenediamine (OPA) with chemical salicylaldehyde, while compounds 2b (2-(2-[(1E)-2-phenylethenyl]-1H-1,3-benzodiazole) and 3b (2-[(1E)-2,6-dimethylhepta-1,5-dien-1-yl]-1H-1,3-benzodiazole) were obtained through a hemi-synthesis process of, respectively, the cinnamon (cinnamaldehyde, 90.54%) and lemongrass (cis-citral, 43.9%) essential oils previously characterized by GC/MS. Compounds 4b (2-phenyl-1H-benzimidazole) and 5b (5-(1H-benzimidazol-2-yl)benzene-1,2,3-triol) were synthesized with a click chemistry method by reacting the OPA with benzoic acid and gallic acid directly in ethanol under microwave irradiation (MW) at 400 MHz. The structure/purity of the synthesized compounds was clarified by spectroscopy, ATR-FTIR and NMR 1H. Compounds 1b5b were screened for their antioxidant activity by using four complementary in-vitro assays: DPPH scavenging activity, ferric ion reducing power, β-carotene bleaching inhibition, and Thiobarbituric Acid Reactive Substance Assay (TBARS) formation inhibition. All the tested compounds showed antioxidant potential, with varying performance. Antimicrobial activity was investigated against American Type Culture Collection (ATCC) strains (three Gram- bacteria: Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa; one Gram+ bacteria: Staphylococcus aureus, and one yeast strain: Candida albicans) through the determination of the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) by using the microdilution method and rapid colorimetric test of p-iodonitrotetrazolium chloride (INT). Compound 5b exhibited the highest potential, especially against S. aureus (MIC = 0.156 mg·mL−1) followed by S. typhi and C. albicans (MIC = 0.3125 mg·mL−1) and then by E. coli and P. aeruginosa. Compound 1b also showed great potential against S. aureus and C. albicans (MIC ˂ 0.3125 mg·mL−1), followed by E. coli and S. typhi (MIC = 0.3125 mg·mL1) and P. aeruginosa (MIC = 0.625 mg·mL−1). Further molecular docking was conducted using AutoDock Vina 1.1.2 software on S. aureus thymidylate kinase (TMK) protein to highlight the structure–activity relationship of the potent molecules. Full article
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Proceeding Paper
New BODIPY Dye with a Large Stokes Shift for Biopolymer Labelling
by Valeria I. Raskolupova, Tatyana V. Popova, Olga D. Zakharova, Tatyana V. Abramova and Vladimir N. Silnikov
Chem. Proc. 2021, 3(1), 72; https://doi.org/10.3390/ecsoc-24-08304 - 14 Nov 2020
Viewed by 1441
Abstract
As the most abundant protein with a variety of physiological functions, human serum albumin (HSA) has been used extensively for the delivery and improvement of therapeutic molecules. Thiolactone chemistry provides a powerful tool to prepare albumin-based multimodal imaging probes and agents for boron [...] Read more.
As the most abundant protein with a variety of physiological functions, human serum albumin (HSA) has been used extensively for the delivery and improvement of therapeutic molecules. Thiolactone chemistry provides a powerful tool to prepare albumin-based multimodal imaging probes and agents for boron neutron capture therapy (BNCT). For this purpose, boron containing 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dye was designed and synthesized. BODIPY dyes are photostable neutral derivatives of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene. These are widely used as chemosensors, laser materials and molecular probes. At the same time, BODIPY dyes, like most other fluorophores, have small or moderate Stokes shifts. Large Stokes shifts are preferred for fluorophores because of higher sensitivity of such probes and sensors. We succeeded in performing an annulation of pyrrole ring with coumarin heterocyclic system and achieved a remarkable difference in absorption and emission maximum of obtained fluorophore up to 100 nm. Moreover, this BODIPY dye was equipped with a linker arm and was functionalized with a maleimide residue specifically reactive towards thiol groups of proteins. The released sulfhydryl groups of the homocysteine functional handle in thiolactone modified HSA was labeled with BODIPY dye to prepare a labeled albumin-BODIPY dye conjugate confirmed by MALDI-TOF-MS, UV-vis and fluorescent emission spectra. The cytotoxicity of HSA conjugate was evaluated by MTT assay in cell lines MCF-7 and T98G. This is the basis for a novel BODIPY dye -albumin theranostic for BNCT. These results provide further impetus to develop derivatives of HSA for delivery of boron to cancer cells. Full article
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Proceeding Paper
Interactions between Isoniazid and α-Hydroxycarboxylic Acids
by Raquel Álvarez-Vidaurre, Alfonso Castiñeiras, Isabel García-Santos and Rocío Torres-Iglesias
Chem. Proc. 2021, 3(1), 73; https://doi.org/10.3390/ecsoc-24-08355 - 14 Nov 2020
Viewed by 1063
Abstract
The present study refers to the preparation of isonicotinic acid hydrazide (isoniazid (INH)) cocrystals with two α-hydroxycarboxylic acids. The interaction of glycolic acid (H2ga) or dl-mandelic acid (H2ma) resulted in the formation of cocrystals, or salts of composition, as [...] Read more.
The present study refers to the preparation of isonicotinic acid hydrazide (isoniazid (INH)) cocrystals with two α-hydroxycarboxylic acids. The interaction of glycolic acid (H2ga) or dl-mandelic acid (H2ma) resulted in the formation of cocrystals, or salts of composition, as isoniazid−glycolic acid cocrystal (INH)·(H2ga) (1) and isoniazid−dl-mandelic acid salt cocrystal [HINH]+[Hma]·(H2ma) (2), when reacted with isoniazid. An N’-(propan-2-ylidene)isonicotinic hydrazide hemihydrate, (pINH)·1/2(H2O) (3), was also prepared by condensation of isoniazid with acetone in the presence of glycolic acid. The prepared compounds were well characterized by elemental analysis and spectroscopic methods, and their three-dimensional molecular structure was determined by single-crystal X-ray crystallography. Hydrogen bonds involving carboxylic acid occur consistently with the pyridine ring N atom of the isoniazid and its derivatives. The remaining hydrogen-bonding sites on the isoniazid backbone vary on the basis of the steric influences of the derivative group. These are contrasted in each of the molecular systems. Full article
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Proceeding Paper
One-Pot Selective Functionalization of Polysaccharides with Urea
by Vanina A. Guntero, Micaela Peralta, Pablo Noriega, María N. Kneeteman and Cristián A. Ferretti
Chem. Proc. 2021, 3(1), 74; https://doi.org/10.3390/ecsoc-24-08346 - 14 Nov 2020
Viewed by 1145
Abstract
Natural polysaccharides are polymers composed of monosaccharide units bound together by glycosidic linkages. In their native form, these polymers may not be able to provide all the desired properties for a particular application. Thus, the functionalization of their reactive hydroxyl groups would change [...] Read more.
Natural polysaccharides are polymers composed of monosaccharide units bound together by glycosidic linkages. In their native form, these polymers may not be able to provide all the desired properties for a particular application. Thus, the functionalization of their reactive hydroxyl groups would change their surface properties. In this work, we evaluated the derivatization of OH groups of maltodextrin polysaccharide with urea. Through a one-pot selective procedure carried out at room temperature for 3 h, urea united at maltodextrin through covalent bonding was obtained. The results show that after functionalization with urea, the pH and solubility in polar solvents of the new material increased. Derivatization of maltodextrin with urea confers stability, and terminal amide groups on the surface of this material represent a versatile reactive functional group for conjugation with other molecules for potential applications in the development of new materials. Full article
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Proceeding Paper
Identification of Natural Products for the Treatment of Alzheimer’s Disease: 3D Similarity Search
by Luminita Crisan, Alina Bora and Liliana Pacureanu
Chem. Proc. 2021, 3(1), 75; https://doi.org/10.3390/ecsoc-24-08341 - 14 Nov 2020
Viewed by 1074
Abstract
Glycogen synthase kinase-3 (GSK-3), one of the main tau kinases involved in a variety of cellular processes, has been evidenced as a promising target for Alzheimer’s disease (AD) treatment. In recent years, great efforts have been made to discover new molecules with an [...] Read more.
Glycogen synthase kinase-3 (GSK-3), one of the main tau kinases involved in a variety of cellular processes, has been evidenced as a promising target for Alzheimer’s disease (AD) treatment. In recent years, great efforts have been made to discover new molecules with an enhanced profile that inhibit GSK-3 and display efficacy in AD treatment. SAR502250, a newly discovered selective GSK-3 inhibitor with AD therapeutic potential, represents a good alternative to design future specific inhibitors against this condition. SAR502250 was used as a query in a 3D similarity search on the SPECS database to select new natural compounds as possible GSK-3 inhibitors. According to ShapeTanimoto, TanimotoCombo, and ComboScore matrics, the first 10 SPECS natural compounds were selected and structurally analyzed. The ADME (Absorption, Distribution, Metabolism, and Excretion), physicochemical parameters, and toxicity-related risk profiles of the selected natural compounds were also investigated. The 3D similarity results in conjunction with pharmaceutical profiles revealed the potential use of natural compounds as GSK-3 inhibitors for Alzheimer’s disease therapy. Full article
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Proceeding Paper
Insight into the Influence of the Chiral Molecular Symmetry on the Chiroptics of Fluorescent BINOL-Based Boron Chelates
by Josué Jiménez, Edurne Avellanal-Zaballa, Sergio Serrano, Alexis R. Torres, Antonia R. Agarrabeitia, Florencio Moreno, Gilles Muller, Jorge Bañuelos, Beatriz L. Maroto and Santiago de la Moya
Chem. Proc. 2021, 3(1), 76; https://doi.org/10.3390/ecsoc-24-08308 - 14 Nov 2020
Cited by 2 | Viewed by 1480
Abstract
The prominent influence of the molecular symmetry, as defined by the symmetry point group, on the chiroptical behavior (electronic circular dichroism and, especially, circularly polarized luminescence) of simple fluorescent boron chelates (BODIPY and related BOPHY analogues) is studied and discussed. It is shown [...] Read more.
The prominent influence of the molecular symmetry, as defined by the symmetry point group, on the chiroptical behavior (electronic circular dichroism and, especially, circularly polarized luminescence) of simple fluorescent boron chelates (BODIPY and related BOPHY analogues) is studied and discussed. It is shown that increasing the dye symmetry by means of the D3 chiral symmetry group is a workable design option to enhance the level of differential emission of right- and left-circularly polarized light in BODIPY dyes and related emitters, and that the influence of the level of symmetry is stronger than the influence of the higher number of chiral moieties perturbing the acting achiral chromophore. Full article
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Proceeding Paper
Lead Finding from Plant Cymbopogon Citratus with Immunomodulator Potentials through in Silico Methods
by Sandeep Waghulde, Prutha Parmar, Jasraj Mule, Diksha Pashte, Bhakti Patil, Namrata Modhale, Nilesh Gorde, Ajay Kharche and Mohan Kale
Chem. Proc. 2021, 3(1), 77; https://doi.org/10.3390/ecsoc-24-08302 - 14 Nov 2020
Viewed by 1374
Abstract
The aim of this study was to examine the correlation between immunomodulators and the molecular properties of the Cymbopogon citratus derivatives in search of a lead compound through molinspiration cheminformatics software. Ten naturally occurring derivatives of Cymbopogon citratus were selected for bioactivity prediction [...] Read more.
The aim of this study was to examine the correlation between immunomodulators and the molecular properties of the Cymbopogon citratus derivatives in search of a lead compound through molinspiration cheminformatics software. Ten naturally occurring derivatives of Cymbopogon citratus were selected for bioactivity prediction and drug likeness score on the basis of Lipinski’s rule. All of the compounds fulfilled Lipinski’s rule as their Milog P score was below 5, suggesting these compounds show good permeability across cell membranes. All the screened compounds had minimum or no violations of the Lipinski rule. Cymbopogon citratus and its derivatives showed a good bioactivity score for drug targets including nuclear receptor ligand, protease inhibitor and enzyme inhibition and thus are expected to have excellent pharmacological activity in vivo. The results of this study justify their topical application as immunomodulators but some structural modifications in order to make the compound more polar would definitely improve oral bioavailability and thus the usefulness and therapeutic efficacy of Cymbopogon citratus. All the Cymbopogon citratus derivatives are predicted to be orally active and are considered as potential candidates for further research as their bioactivity score due to high affinity for various drug targets was better than the standard as well as among other tested compounds. Full article
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Proceeding Paper
Synthesis and Quantum-Chemical Studies of New Hybrid Heterocyclic Molecules Derived from 3-(Thiocyanatoacetyl)Coumarin
by Natalya S. Tatarchenko, Vyacheslav K. Kindop, Alexander V. Bespalov, Victor V. Dotsenko and Nicolai A. Aksenov
Chem. Proc. 2021, 3(1), 78; https://doi.org/10.3390/ecsoc-24-08104 - 13 Nov 2020
Viewed by 982
Abstract
3-(Thiocyanatoacetyl)coumarin, prepared by a reaction of 3-(bromoacetyl)coumarin with KSCN, reacts with primary aryl amines to give new hybrid heterocyclic products, 3-(3-aryl-2-imino-2,3-dihydrothiazol-4-yl)-2Н-chromen-2-ones. The structures and conformational features of the products have been studied by the B3LYP-D3/6-311G(d,p) method. Full article
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Proceeding Paper
Synthesis and Characterization of a meso-Anthracene-BODIPY Derivative for Colorimetric Recognition of Cu2+ and Fe3+
by Sónia C. S. Pinto, Raquel C. R. Gonçalves, Susana P. G. Costa and Maria Manuela M. Raposo
Chem. Proc. 2021, 3(1), 79; https://doi.org/10.3390/ecsoc-24-08292 - 14 Nov 2020
Cited by 2 | Viewed by 1125
Abstract
Ions exist widely in biological and environmental media, and the scarcity or excess of these species can have adverse consequences. BODIPY dyes appear as heterocyclic organic compounds capable of recognizing metal ions in solution and in cells, through optical signals (colorimetric and/or fluorimetric), [...] Read more.
Ions exist widely in biological and environmental media, and the scarcity or excess of these species can have adverse consequences. BODIPY dyes appear as heterocyclic organic compounds capable of recognizing metal ions in solution and in cells, through optical signals (colorimetric and/or fluorimetric), and their photophysical properties can be adjusted through the functionalization of the BODIPY core. In continuation of the work developed recently, our research group reports the synthesis of a meso-anthracene-BODIPY derivative and the respective characterization by 1H and 13C nuclear magnetic resonance (NMR) and UV-Vis absorption spectroscopies. The preliminary study of the chemosensory capacity of the BODIPY derivative was also carried out in the presence of several cations in acetonitrile solution, which shows a selective colorimetric response for Cu2+ and Fe3+. Full article
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Proceeding Paper
Synthesis and Structural Characterization of Imidazolium-Based Dicationic Ionic Liquids
by Nassima Medjahed, Mansour Debdab, Boumediene Haddad, Elhabib Belarbi, Zahira KIBOU, Amina Berrichi, Redouane Bachir and Noureddine Choukchou-Braham
Chem. Proc. 2021, 3(1), 80; https://doi.org/10.3390/ecsoc-24-08389 - 14 Nov 2020
Cited by 3 | Viewed by 1684
Abstract
Dicationic ionic liquids present a novel class of ionic liquids composed of dication and two monoanions; the latter have shown an increasing interest in recent years and are used in many applications. Compared to conventional ionic liquids, the physicochemical properties of dicationic ionic [...] Read more.
Dicationic ionic liquids present a novel class of ionic liquids composed of dication and two monoanions; the latter have shown an increasing interest in recent years and are used in many applications. Compared to conventional ionic liquids, the physicochemical properties of dicationic ionic liquids can be set by modifying the languor and the type of chains linking the cationic heads as well as the type of cation. In this work, we present the synthesis of three dicationic ionic liquids based on imidazolium with two steps; the first of which is a quaternization reaction leading to the formation of dicationic ionic liquids with the iodide ion. The characterization of these organic salts was carried out by magnetic resonance spectroscopy, allowing a better identification of the products obtained. Full article
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Proceeding Paper
Lactamomethylation of Phenols: Synthesis, In Silico Study of Reactivity and Possible Applications
by Stepan Vorobyev, Olga Primerova and Vladimir Koshelev
Chem. Proc. 2021, 3(1), 81; https://doi.org/10.3390/ecsoc-24-08408 - 14 Nov 2020
Cited by 1 | Viewed by 1118
Abstract
Lactamomethylation of phenols with various substituents was provided by pyrrolidone, valerolactam, caprolactam, and 4-phenylpyrrolidone derivatives. The structures of the target compounds were confirmed by IR and NMR study. The behavior of alkylphenols (2,4-di-tert-butyl- and thymol), diphenols (catechol and hydroquinone), formylphenol (vanillin), and hydroxybenzoic [...] Read more.
Lactamomethylation of phenols with various substituents was provided by pyrrolidone, valerolactam, caprolactam, and 4-phenylpyrrolidone derivatives. The structures of the target compounds were confirmed by IR and NMR study. The behavior of alkylphenols (2,4-di-tert-butyl- and thymol), diphenols (catechol and hydroquinone), formylphenol (vanillin), and hydroxybenzoic acids (salicylic and resorcylic) in this reaction was compared by quantum-chemical calculations. For several compounds, the energy of dissociation of the ArO-H bond was calculated by quantum-chemical method to reveal their possible antioxidant activity. In addition, the ability of synthesized compounds to destruct cumene hydroperoxide was studied. It was estimated that 1-(4-hydroxy-5-isopropil-2-methylbenzyl)azepan-2-one and 1-(4-hydroxy-5-isopropil-2-methylbenzyl)pyrrolidin-2-one possess the best antioxidant effect, comparable to the one of industrial additive butylated hydroxytoluene (BHT). Full article
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Proceeding Paper
On the Use of CeCl3.7H2O as a Catalyst for the Synthesis of Hydrazones Derived from Aromatic Aldehydes and Ketones
by Didier Farley Vargas, Brenda S. Romero, Teodoro Saul Kaufman and Enrique Leandro Larghi
Chem. Proc. 2021, 3(1), 82; https://doi.org/10.3390/ecsoc-24-08095 - 13 Nov 2020
Cited by 1 | Viewed by 1430
Abstract
Hydrazonation of acetophenones and benzaldehydes under CeCl3 assistance was evaluated. The transformations entailed the use of the respective hydrazines (H2N–NH2.HCl, Me2N–NH2, or Ph2N–NH2.HCl) and CeCl3.7H2O (2–5 [...] Read more.
Hydrazonation of acetophenones and benzaldehydes under CeCl3 assistance was evaluated. The transformations entailed the use of the respective hydrazines (H2N–NH2.HCl, Me2N–NH2, or Ph2N–NH2.HCl) and CeCl3.7H2O (2–5 mol %). The use of different solvents in a model reaction between 3,4-dimethoxybenzaldehyde and N,N-dimethylhydrazine was studied. Full article
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345 KiB  
Proceeding Paper
Synthesis of Epoxyisoindolinones via Microwave-Assisted Ugi-4CR/Intramolecular-Diels-Alder Reaction
by Fernando Torres-Hernández, Ángel Rentería-Gómez and Rocío Gámez-Montaño
Chem. Proc. 2021, 3(1), 83; https://doi.org/10.3390/ecsoc-24-08425 - 14 Nov 2020
Cited by 1 | Viewed by 1097
Abstract
A series of epoxyisoindolinones were synthesized by microwave-assisted post-IMCR transformation-based domino strategy via the Ugi-4CR/Intramolecular-Diels-Alder (U-4CR/IMDA) sequence under mild, solvent-, catalyst-free ecofriendly conditions, and orthogonal-bifunctional components. Epoxyisoindolinones are a privileged core of high interest in medicinal chemistry mainly for its anticancer activity in [...] Read more.
A series of epoxyisoindolinones were synthesized by microwave-assisted post-IMCR transformation-based domino strategy via the Ugi-4CR/Intramolecular-Diels-Alder (U-4CR/IMDA) sequence under mild, solvent-, catalyst-free ecofriendly conditions, and orthogonal-bifunctional components. Epoxyisoindolinones are a privileged core of high interest in medicinal chemistry mainly for its anticancer activity in several cell lines. Full article
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309 KiB  
Proceeding Paper
Ecotoxicity of Mixtures of IL and Lithium Salt
by Juan José José Parajó, Pablo Vallet, Lois Fernádez-Míguez, María Villanueva and Josefa Salgado
Chem. Proc. 2021, 3(1), 84; https://doi.org/10.3390/ecsoc-24-08361 - 14 Nov 2020
Cited by 1 | Viewed by 1028
Abstract
The applicability of ionic liquids (IL) has been increased during the last years and even new opportunities are becoming a reality, i.e., mixtures of pure IL and inorganic salt as electrolytes for smart electrochemical devices. In this work, the ecotoxicity of two protic [...] Read more.
The applicability of ionic liquids (IL) has been increased during the last years and even new opportunities are becoming a reality, i.e., mixtures of pure IL and inorganic salt as electrolytes for smart electrochemical devices. In this work, the ecotoxicity of two protic ILs (Ethylammonium nitrate and Ethylimidazolium nitrate) and one aprotic IL (butylmethylpyrrolidinium bis(trifluoroomethylsulfonyl)imide) doped with the corresponding Lithium salt was tested towards changes on the bioluminescence of the bacteria Aliivibrio fischeri, using the Microtox® standard toxicity test. Half maximal effective concentration (EC50) of these mixtures was determined over three standard periods of time and compared with the corresponding values to pure ILs. Full article
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485 KiB  
Proceeding Paper
Ecotoxicological Evaluation of Ethylammonium Nitrate and Aluminium Salt Mixture
by Carlota Ucha, Otilia Reyes, Carmen Trasar-Cepeda, Josefa Salgado and Juan José Parajó
Chem. Proc. 2021, 3(1), 85; https://doi.org/10.3390/ecsoc-24-08364 - 14 Nov 2020
Viewed by 965
Abstract
The ecotoxicity of a mixture of the ionic liquid ethylammonium nitrate (EAN) and aluminum nitrate salt (Al(NO3)3), as well as the corresponding pure components, was studied in this work. This mixture is of singular interest as electrolytes in electrochemical [...] Read more.
The ecotoxicity of a mixture of the ionic liquid ethylammonium nitrate (EAN) and aluminum nitrate salt (Al(NO3)3), as well as the corresponding pure components, was studied in this work. This mixture is of singular interest as electrolytes in electrochemical applications and data on the effects of mixture and components on the environment can hardly be found in the literature. Changes in the bioluminescence of the Aliivibrio fischeri (Beijerinck) Urbanczyk bacteria, determined through a Microtox® test, and microbial activity, measured by microcalorimetry, of two soils with different organic matter contents when exposed to solutions of different concentrations of these compounds were analyzed. Full article
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758 KiB  
Proceeding Paper
Synthesis of (2S,3S)-3-Aroyl Pyroglutamic Acid Amides
by Lucia Pincekova and Dusan Berkes
Chem. Proc. 2021, 3(1), 86; https://doi.org/10.3390/ecsoc-24-08377 - 14 Nov 2020
Viewed by 1254
Abstract
A new methodology for the asymmetric synthesis of enantiomerically enriched 3-aroyl pyroglutamic acid derivatives has been developed through effective 5-exo-tet cyclization of N-chloroacetyl aroylalanines. The three-step sequence starts with the synthesis of N-substituted (S,S)-2-amino-4-aryl-4-oxobutanoic acids [...] Read more.
A new methodology for the asymmetric synthesis of enantiomerically enriched 3-aroyl pyroglutamic acid derivatives has been developed through effective 5-exo-tet cyclization of N-chloroacetyl aroylalanines. The three-step sequence starts with the synthesis of N-substituted (S,S)-2-amino-4-aryl-4-oxobutanoic acids via highly diastereoselective tandem aza-Michael addition and crystallization-induced diastereomer transformation (CIDT). Their N-chloroacetylation followed by base-catalyzed cyclization and ultimate acid-catalyzed removal of chiral auxiliary without loss of stereochemical integrity furnishes the target substituted pyroglutamic acids. Finally, several series of their benzyl amides were prepared as 3-aroyl analogs of known P2X7 antagonists. Full article
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315 KiB  
Proceeding Paper
One-Step Synthesis of 5a,11a-Janusene Imide Employing 2,3-Dibromo-N-methylmaleimide as Acetylene Equivalent
by Petar Štrbac and Davor Margetić
Chem. Proc. 2021, 3(1), 87; https://doi.org/10.3390/ecsoc-24-08426 - 14 Nov 2020
Viewed by 1005
Abstract
Synthesis of janusene (5,5a,6,11,11a,12-hexahydro-5,12:6,11-di-o-benzenonaphthacene) requires several reaction steps, starting from anthracene. In this account, a one-pot, three-step synthesis of janusene N-methyl-5a,11a-dicarboximide employing 2,3-dibromo-N-methylmaleimide as an acetylene equivalent is described. This thermal reaction is a simple synthetic procedure in [...] Read more.
Synthesis of janusene (5,5a,6,11,11a,12-hexahydro-5,12:6,11-di-o-benzenonaphthacene) requires several reaction steps, starting from anthracene. In this account, a one-pot, three-step synthesis of janusene N-methyl-5a,11a-dicarboximide employing 2,3-dibromo-N-methylmaleimide as an acetylene equivalent is described. This thermal reaction is a simple synthetic procedure in comparison to sequential-multi step [4+2] cycloaddition routes. Here, 2,3-dibromo-N-methylmaleimide acts effectively as a ‘molecular glue’, bridging two anthracene molecules together. Full article
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369 KiB  
Proceeding Paper
Heterocyclic Aldehydes Based on Thieno[3,2-b]thiophene Core: Synthesis and Preliminary Studies as Ion Optical Chemosensors
by Rui P. C. L. Sousa, Raquel C. R. Gonçalves, Susana P. G. Costa, Rita B. Figueira and Maria Manuela M. Raposo
Chem. Proc. 2021, 3(1), 88; https://doi.org/10.3390/ecsoc-24-08092 - 13 Nov 2020
Cited by 1 | Viewed by 1723
Abstract
Heterocyclic aldehydes show a variety of optical properties and the versatility of their reactivity allows them to yield a wide range of more complex compounds, with application in areas such as medicinal, materials and supramolecular chemistry. The biological and environmental relevance of certain [...] Read more.
Heterocyclic aldehydes show a variety of optical properties and the versatility of their reactivity allows them to yield a wide range of more complex compounds, with application in areas such as medicinal, materials and supramolecular chemistry. The biological and environmental relevance of certain molecules and ions turns them into targets for the design of molecular recognition systems. Recently, heterocyclic aldehydes have been reported in the literature as ion chemosensors. Following the group’s work on optical chemosensors, for the detection and quantification of ions and molecules with environmental and medicinal relevance, this work reports the synthesis and characterization of two heterocyclic aldehydes based on the thieno[3,2-b]thiophene core, by Suzuki coupling, as well as the synthesis of the corresponding precursors. Preliminary chemosensory studies for the synthesized heterocyclic aldehydes in the presence of selected cations were also performed, in solution, in order to determine their potential application as optical chemosensors. Full article
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440 KiB  
Proceeding Paper
ZnFe2O4@dimethylglyoxime: Preparation and Catalyst Application in the Synthesis of 2-Amino-tetrahydro-4H-chromene-3-carbonitrile Derivatives
by Haniyeh Dogari, Fereshte Hassanzadeh-Afruzi and Ali Maleki
Chem. Proc. 2021, 3(1), 89; https://doi.org/10.3390/ecsoc-24-08287 - 14 Nov 2020
Cited by 2 | Viewed by 1133
Abstract
Hybrid materials constructed from two or more constituents provide new features and distinctive applications which not found in the single-part material. Spinel ferrites with the general formula of AB2O4, where A denotes divalent ions and B represents trivalent ions, [...] Read more.
Hybrid materials constructed from two or more constituents provide new features and distinctive applications which not found in the single-part material. Spinel ferrites with the general formula of AB2O4, where A denotes divalent ions and B represents trivalent ions, appeared as efficient catalysts for the synthesis of organic compounds. These magnetic nanoparticles have both the Lewis acid and the Lewis base sites in their structure. In the present study, ZnFe2O4 was prepared and modified with dimethylglyoxime to obtain a magnetic ZnFe2O4@dimethylglyoxime hybrid catalyst. Dimethylglyoxime is a dibasic acid substance that has been used as a chelating agent for divalent metal ions due to containing two nitrogen atoms and hydroxyl groups. Surface modification of zinc ferrite with this dibasic acid substance produced a bifunctional hybrid catalyst with increased catalytic active sites. In the next step, a prepared catalyst was applied in the synthesis of 2-amino-tetrahydro-4H-chromene-3-carbonitrile derivatives by condensation of aromatic aldehydes, malononitrile and dimedone in ethanol at room temperature. The present method offers advantages such as simple procedure, mild reaction condition, short reaction times and retrievable catalyst. Full article
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515 KiB  
Proceeding Paper
Diplodomica II. Repugnatorial Secretion of Ecuadorian Endemic Millipede Rhinocricus sp. (Diplopoda, Spirobolida, Rhinocricidae) from Orellana Province, Amazonia, Ecuador
by Juan Enrique Tacoronte Morales and Maria Teresa Cabrera
Chem. Proc. 2021, 3(1), 90; https://doi.org/10.3390/ecsoc-24-08435 - 14 Nov 2020
Viewed by 1011
Abstract
Millipedes (Myriapoda: Diplopoda) represents one of the oldest and most evolutionary successful classes of invertebrates. The order Spirobolida is dominantly tropical, and the family Rhinocricidae is widely distributed in the Ecuadorian edaphic fauna inhabiting the Amazonia region. The millipedes collected were stimulated mechanically, [...] Read more.
Millipedes (Myriapoda: Diplopoda) represents one of the oldest and most evolutionary successful classes of invertebrates. The order Spirobolida is dominantly tropical, and the family Rhinocricidae is widely distributed in the Ecuadorian edaphic fauna inhabiting the Amazonia region. The millipedes collected were stimulated mechanically, and an ejected repugnatorial fluid was subjected to structural analysis. The analysis of the defensive–repugnatorial secretion of the endemic millipede Rhinocricus sp., inhabiting in the Amazonian region of Orellana, Republic of Ecuador, and chemical evidence (chromogenic reactions: KI starch paper and rodanine test in aqueous ammonia) as well, revealed the quinonoide composition of the secretion. We identified 2-methyl-3-methoxy-1,4-benzoquinone as an active major component. Full article
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158 KiB  
Proceeding Paper
Influence of Nonpolar Medium on Antioxidant Capacity of Bergaptol and Xanthotoxol—Kinetic DFT Study
by Žiko Milanović, Marko Antonijević, Jelena Đorović Jovanović, Edina Avdović, Dejan Milenković and Zoran Marković
Chem. Proc. 2021, 3(1), 91; https://doi.org/10.3390/ecsoc-24-08100 - 13 Nov 2020
Cited by 1 | Viewed by 916
Abstract
Within this study, the antioxidant capacity of bergaptol (BER) and xanthotoxol (XAN) in a nonpolar environment (benzene) was investigated against the reference standard trolox (Tx). The ability to inactivate HO radicals from the kinetic aspect was examined through hydrogen atom transfer (HAT), [...] Read more.
Within this study, the antioxidant capacity of bergaptol (BER) and xanthotoxol (XAN) in a nonpolar environment (benzene) was investigated against the reference standard trolox (Tx). The ability to inactivate HO radicals from the kinetic aspect was examined through hydrogen atom transfer (HAT), single-electron transfer–proton transfer (SET-PT), sequential proton loss electron transfer (SPLET) and radical adduct formation (RAF) mechanisms. The rate constants of the chemical reaction were calculated using the conventional transition state theory (TST) and Eckart method (ZCT_0). The research is based on a QM-ORSA (Quantum Mechanics–based test for Overall free-Radical Scavenging Activity) protocol. For this purpose, the Gaussian 09 software package with the M06-2X/6-311++G(d,p) theoretical model was used. It has been shown that both compounds in benzene can inactivate the HO radical via HAT and RAF mechanisms. The calculated kinetic parameters indicate that the TST method, in some positions, is not suitable for calculating reaction rate constants at room temperature. Based on relative antioxidant capacity (rT), both compounds showed better antioxidant capacity than Tx, and it should be emphasized that BER showed better activity than XAN. Based on the relative amount of products (Гi) of both compounds, it was concluded that the formation of a radical adduct in positions C-3, C-5, C-8, and C-2' is the most represented. Full article
534 KiB  
Proceeding Paper
Green Synthesis of Symmetric Dimaleamic Acids from Dianilines and Maleic Anhydride: Behind New Bidentate Ligands for MOFs
by Julio C. Flores-Reyes, José L. Sosa-Juárez, Mayra Sánchez-Serratos, Perla Islas-Jácome, Atilano Gutiérrez-Carrillo, Francisco Méndez, Galdina V. Suárez-Moreno, Alejandro Islas-Jácome and Eduardo González-Zamora
Chem. Proc. 2021, 3(1), 92; https://doi.org/10.3390/ecsoc-24-08379 - 14 Nov 2020
Viewed by 1376
Abstract
We herein report the synthesis and characterization of six α,β-unsaturated dicarboxylic acid ligands with different phenyl spacers, and two ligands with a biphenyl and anthraquinone spacers. All these dimaleamic acids were synthesized in 16 to 99% yields via a base-catalyzed maleimide ring opening [...] Read more.
We herein report the synthesis and characterization of six α,β-unsaturated dicarboxylic acid ligands with different phenyl spacers, and two ligands with a biphenyl and anthraquinone spacers. All these dimaleamic acids were synthesized in 16 to 99% yields via a base-catalyzed maleimide ring opening in water (ligand 2), or by a di-N-acylation from the corresponding diamines and maleic anhydride in acetic acid (ligands 4, 6, 8, 10, 12, 14 and 16). These reactions were performed using green solvents, while requiring minimal work up procedures, making them suitable alternatives to access these types of bidentate ligands quickly, which can be used to fabricate new metal-organic frameworks (MOFs). Full article
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