Organics

19 pages, 6040 KB

Open AccessEditor’s ChoiceReview

Aniline and Beyond: A Multifaceted Case Study for a Bildung-Focused Chemical Education

by Teresa Celestino

Organics 2025, 6(2), 20; https://doi.org/10.3390/org6020020 - 1 May 2025

Cited by 1 | Viewed by 3862

In the chemical education field, the Johnstone’s triangle represents three learning levels (symbolic, macroscopic, and molecular) needed for students. Afterwards, Mahaffy suggested a tetrahedron model based on this triangle, where the top represents the human element. Subsequently, Sjöström proposed a subdivision of the [...] Read more.

In the chemical education field, the Johnstone’s triangle represents three learning levels (symbolic, macroscopic, and molecular) needed for students. Afterwards, Mahaffy suggested a tetrahedron model based on this triangle, where the top represents the human element. Subsequently, Sjöström proposed a subdivision of the top into three other levels: applied chemistry, socio-cultural context, and critical–philosophic approach. These six dimensions of chemical knowledge will be examined in relation to the discovery of aniline, its chemistry and applications. The historical and epistemic aspects of this topic, gradually broadening the focus to the social, political, and artistic backdrop, can provide a more effective approach to teaching the subject. The major impact of the synthetic dye industry makes this field of study particularly important for a Bildung-focused chemistry education. Full article

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18 pages, 2491 KB

Open AccessEditor’s ChoiceReview

Use and Roles of Tannins in Polysaccharide-Based Bioplastics and Biocomposites

by Carlo Santulli, Serena Gabrielli and Graziella Roselli

Organics 2025, 6(2), 19; https://doi.org/10.3390/org6020019 - 1 May 2025

Cited by 4 | Viewed by 3725

Abstract

Most bioplastics are based on polysaccharides, which are either synthesized from a variously sourced monomer or extracted from some biomass waste. In many cases, some lignocellulosic fibers are then added to the obtained bioplastics to form biocomposites and extend their range of applications [...] Read more.

Most bioplastics are based on polysaccharides, which are either synthesized from a variously sourced monomer or extracted from some biomass waste. In many cases, some lignocellulosic fibers are then added to the obtained bioplastics to form biocomposites and extend their range of applications beyond packaging films and generically easily biodegradable materials. Plant-extracted tannins, which, as such, might also be building blocks for bioplastics, do nonetheless represent a useful complement in their production when added to polysaccharide-based plastics and biocomposites, since they offer other functions, such as bioadhesion, coloration, and biocidal effect. The variety of species used for tannin extraction and condensation is becoming very wide and is also connected with the local availability of amounts of bio-waste from other productions, such as from the food system. This work tries to summarize the evolution and recent developments in tannin extraction and their increasing centrality in the production of polysaccharide-based plastics, adhesives, and natural fiber composites. Full article

(This article belongs to the Special Issue Chemistry of Heterocyclic Compounds)

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18 pages, 4205 KB

Open AccessEditor’s ChoiceArticle

Synthesis of Bipyridine Ether-Type Bifunctional Precursors

by Bálint Jávor, Antal Agárdi, Péter Kisfaludi, Barnabás Frigyes, Márton Temesvári, Panna Vezse, Tünde Tóth, Péter Huszthy and Ádám Golcs

Organics 2025, 6(2), 18; https://doi.org/10.3390/org6020018 - 10 Apr 2025

Viewed by 2527

Abstract

Bipyridine ethers are commonly occurring structural motifs in supramolecular chemistry. The herein reported efforts aim to extend the synthetic platform of bipyridino-precursors with new bifunctional intermediates and to improve some previously reported synthetic strategies for structural analogues, like bipyridine-diols as common macrocycle precursors. [...] Read more.

Bipyridine ethers are commonly occurring structural motifs in supramolecular chemistry. The herein reported efforts aim to extend the synthetic platform of bipyridino-precursors with new bifunctional intermediates and to improve some previously reported synthetic strategies for structural analogues, like bipyridine-diols as common macrocycle precursors. In addition, their optimized and highly efficient oxidation to the corresponding dialdehydes is reported to obtain further reactive intermediates with wide modifiability. Furthermore, methylations of pyridine-carbaldehydes were carried out alongside different synthetic strategies to introduce chirality centers. Synthetic difficulties and some unsuccessful approaches are also reported to help in focusing future efforts. Full article

(This article belongs to the Special Issue Chemistry of Heterocyclic Compounds)

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13 pages, 3347 KB

Open AccessEditor’s ChoiceArticle

Small Deviations in Geometries Affect Detonation Velocities and Pressures of Nitroaromatic Molecules

by Danijela S. Kretić, Marija I. Maslarević and Dušan Ž. Veljković

Organics 2025, 6(2), 17; https://doi.org/10.3390/org6020017 - 9 Apr 2025

Cited by 2 | Viewed by 1605

Abstract

Understanding the factors that affect the detonation performance of high-energy molecules (HEMs) is crucial for the design of novel explosives and fuels with desirable characteristics. While molecular factors, such as the presence of specific functional groups that give organic molecules explosive properties, are [...] Read more.

Understanding the factors that affect the detonation performance of high-energy molecules (HEMs) is crucial for the design of novel explosives and fuels with desirable characteristics. While molecular factors, such as the presence of specific functional groups that give organic molecules explosive properties, are key determinants of detonation characteristics, other factors like the geometry of molecules in crystal structures can also affect the high-energy properties of materials. Although it is known that slight deviations in the crystal structure geometry affect the sensitivity of nitroaromatic explosives, the influence of these variations on detonation performance remains unknown. In this study, we extracted different crystal structures of the same high-energy nitroaromatic molecules from the Cambridge Structural Database and calculated their detonation velocities and pressures using the Kamlet–Jacobs equations. Results indicated that different geometries of the same crystal structure can lead to non-negligible differences in detonation velocities and pressures. In the case of the 2,4,6-triamino-1,3,5-trinitrobenzene molecule, discrepancies in detonation pressures among different crystal structures were calculated to be 7.68%. Analysis of geometrical arrangements showed that these differences are mainly the consequence of diverse non-covalent bonding patterns that affect crystal densities. Full article

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49 pages, 14143 KB

Open AccessEditor’s ChoiceReview

An Overview of Quinolones as Potential Drugs: Synthesis, Reactivity and Biological Activities

by Ayoub El-mrabet, Amal Haoudi, Youssef Kandri-Rodi and Ahmed Mazzah

Organics 2025, 6(2), 16; https://doi.org/10.3390/org6020016 - 3 Apr 2025

Cited by 9 | Viewed by 11681

Abstract

Quinolones represent one of the largest classes of synthetic antibiotics used in both human and veterinary medicine. Since the discovery of nalidixic acid, a substantial body of research has been carried out on quinolones, resulting in the synthesis of several quinolone derivatives with [...] Read more.

Quinolones represent one of the largest classes of synthetic antibiotics used in both human and veterinary medicine. Since the discovery of nalidixic acid, a substantial body of research has been carried out on quinolones, resulting in the synthesis of several quinolone derivatives with exceptional pharmacology. In addition to their antibacterial action, quinolones have a broad spectrum of diverse biological activities. In this regard, the present review examines the literature of recent years describing synthesis protocols, reactivity and biological properties, with particular emphasis on the antibacterial, antimalarial, antitrypanosomal, antileishmanial, antiviral and anticancer activities of this famous class of molecules. Finally, this review highlights the potential of quinolones as preferred pharmacophores in medicinal chemistry. The aim is to highlight the innovative aspects of the rational design of new therapeutic agents with this structural motif, in the face of emerging antibiotic resistance and the urgent need for new active molecules. Full article

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16 pages, 3593 KB

Open AccessEditor’s ChoiceArticle

Luminescence of the Conjugate Bases of [2-(2-Hydroxyphenyl)phenyl]phosphinic Acid and Single-Crystal X-Ray Structure Determination of Sodium [2-(2-Hydroxyphenyl)phenyl]phosphinate

by Valeria Gagliardi, Jesús Castro, Valentina Beghetto, María Expósito and Marco Bortoluzzi

Organics 2025, 6(1), 10; https://doi.org/10.3390/org6010010 - 3 Mar 2025

Cited by 2 | Viewed by 1946

Abstract

The commercial flame-retardant 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was almost quantitatively converted in sodium [2-(2-hydroxyphenyl)phenyl]phosphinate Na[OH-Ph-Ph-PHO₂] and disodium 2-(2-phosphinatophenyl)benzen-1-olate Na₂[O-Ph-Ph-PHO₂] under mild reaction conditions and without the use of toxic reactants. The structure of Na[OH-Ph-Ph-PHO₂] was determined by [...] Read more.

The commercial flame-retardant 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was almost quantitatively converted in sodium [2-(2-hydroxyphenyl)phenyl]phosphinate Na[OH-Ph-Ph-PHO₂] and disodium 2-(2-phosphinatophenyl)benzen-1-olate Na₂[O-Ph-Ph-PHO₂] under mild reaction conditions and without the use of toxic reactants. The structure of Na[OH-Ph-Ph-PHO₂] was determined by means of single-crystal X-ray diffraction. The inter- and intramolecular Na-O interactions generate a stair-like framework where the sodium cations are five-coordinated and exhibit a highly distorted coordination sphere. The two compounds are characterized by appreciable blue luminescence at the solid state upon excitation with UV light, attributed to S₁→S₀ decays on the basis of time-resolved measurements and computational calculations. The photoluminescence quantum yield is higher for Na₂[O-Ph-Ph-PHO₂], and the emission and excitation bands are shifted at longer wavelengths. The disodium salt showed affinity towards cellulose, and doped Na₂[O-Ph-Ph-PHO₂]@cellulose samples maintained emission features comparable to those of the pure compound. The nature of the interaction between cellulose and the emitting species was studied by means of periodic density functional theory calculations, that highlighted the role of the sodium cations. Full article

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17 pages, 2664 KB

Open AccessEditor’s ChoiceReview

Ferrocene Derivatives as Histone Deacetylase Inhibitors: Synthesis and Biological Evaluation

by Rostislava Angelova and Georgi Stavrakov

Organics 2025, 6(1), 4; https://doi.org/10.3390/org6010004 - 26 Jan 2025

Cited by 2 | Viewed by 2546

Abstract

Ferrocene is an organometallic compound that has attracted considerable scientific interest due to its unique properties, including low toxicity, excellent stability in aqueous and aerobic media, and high lipophilicity, which enhances membrane permeability. The ferrocene moiety has been effectively used as a bioisostere [...] Read more.

Ferrocene is an organometallic compound that has attracted considerable scientific interest due to its unique properties, including low toxicity, excellent stability in aqueous and aerobic media, and high lipophilicity, which enhances membrane permeability. The ferrocene moiety has been effectively used as a bioisostere of phenyl rings and heteroaromatic groups in the structures of approved tyrosine kinase inhibitors and histone deacetylase inhibitors (HDACis). HDACis exert their cytotoxic effects by blocking cyclin/CDK complexes, causing cell cycle arrest, inducing apoptosis, inhibiting angiogenesis, and through non-histone-directed mechanisms. This mini-review summarizes the synthesis and biological evaluation of small libraries of compounds in which a ferrocenyl moiety is incorporated into the structure of suberoylanilide hydroxamic acid (SAHA) and a number of analogues. The influence of the organometallic function on the antiproliferative effect is investigated. Both docking analysis and in vitro studies confirm that the ferrocenyl-modified HDACis exhibit potent cytotoxicity and strong inhibitory activity against the various enzyme isoforms. Full article

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16 pages, 2321 KB

Open AccessEditor’s ChoiceReview

Synthesis and Pharmacology of Clinical Drugs Containing Isoindoline Heterocycle Core

by Mukund Jha, Dani Youssef, Haley Sheehy and Amitabh Jha

Organics 2025, 6(1), 3; https://doi.org/10.3390/org6010003 - 14 Jan 2025

Cited by 6 | Viewed by 5486

Abstract

Heterocyclic compounds are the cornerstone for active pharmaceutical ingredients. Among heterocycles, isoindoline core occupies a special place, as ten commercial bioactive compounds/drugs contain this skeleton decorated with several functional groups required for optimal receptor binding. These drugs are employed for indications such as [...] Read more.

Heterocyclic compounds are the cornerstone for active pharmaceutical ingredients. Among heterocycles, isoindoline core occupies a special place, as ten commercial bioactive compounds/drugs contain this skeleton decorated with several functional groups required for optimal receptor binding. These drugs are employed for indications such as multiple myeloma, leukemia, inflammation, hypertension, edema, obesity, and insect control. This review presents the pharmacological activities, mechanisms of action, and chemical syntheses of these commercial bioactive molecules/drugs. Full article

(This article belongs to the Special Issue Chemistry of Heterocyclic Compounds)

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18 pages, 3468 KB

Open AccessEditor’s ChoiceReview

Environmental Fate, Ecotoxicity, and Remediation of Heterocyclic Pharmaceuticals as Emerging Contaminants: A Review of Long-Term Risks and Impacts

by Oussama Baaloudj, Laura Scrano, Sabino Aurelio Bufo, Lee-Ann Sade Modley, Filomena Lelario, Angelica Rebecca Zizzamia, Lucia Emanuele and Monica Brienza

Organics 2025, 6(1), 1; https://doi.org/10.3390/org6010001 - 2 Jan 2025

Cited by 14 | Viewed by 5112

Abstract

Heterocyclic pharmaceuticals are emerging contaminants due to their toxic, carcinogenic nature and detrimental impact on the natural ecosystem. These compounds pose a significant environmental concern given their widespread use in medical therapy, constituting over 90% of new medications. Their unique chemical structure contributes [...] Read more.

Heterocyclic pharmaceuticals are emerging contaminants due to their toxic, carcinogenic nature and detrimental impact on the natural ecosystem. These compounds pose a significant environmental concern given their widespread use in medical therapy, constituting over 90% of new medications. Their unique chemical structure contributes to their persistence in various environmental matrices, necessitating urgent measures to mitigate their risks. This review comprehensively examines the sources, environmental fate, toxicity, and long-term risks associated with heterocyclic pharmaceuticals, proposing potential remediation strategies. The article commences with an overview of the diverse types of heterocyclic pharmaceuticals and their applications, focusing on compounds containing heteroatoms such as nitrogen, oxygen, and sulfur. Subsequently, it explores the sources and pathways through which these pollutants enter the environment, including wastewater discharge, agricultural runoff, improper disposal, resistance to biodegradation, and bioaccumulation. The toxic effects and long-term consequences of exposure to heterocyclic pharmaceuticals are then discussed, encompassing neurotoxicity, genotoxicity, mutagenesis, cardiovascular and metabolic toxicity, carcinogenicity, and teratogenesis. Additionally, this review summarizes various remediation strategies and treatment solutions aimed at reducing the environmental impact of these compounds, drawing insights from the literature. The research concludes by identifying critical areas for future research, emphasizing the urgent need for more effective remediation strategies to address the growing concern posed by these emerging contaminants. Full article

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34 pages, 6479 KB

Open AccessEditor’s ChoiceReview

Aldehydes: What We Should Know About Them

by Alessia Catalano, Annaluisa Mariconda, Assunta D’Amato, Domenico Iacopetta, Jessica Ceramella, Maria Marra, Carmela Saturnino, Maria Stefania Sinicropi and Pasquale Longo

Organics 2024, 5(4), 395-428; https://doi.org/10.3390/org5040021 - 21 Oct 2024

Cited by 27 | Viewed by 22795

Abstract

From Egyptian mummies to the Chanel N° 5 perfume, aldehydes have been used for a long time and continue to impact our senses in a wide range of perfumes, foods, and beverages. Aldehydes represent one of the categories of volatile organic compounds (VOCs), [...] Read more.

From Egyptian mummies to the Chanel N° 5 perfume, aldehydes have been used for a long time and continue to impact our senses in a wide range of perfumes, foods, and beverages. Aldehydes represent one of the categories of volatile organic compounds (VOCs), which are categorized as chemicals with boiling points up to 260 °C and can be found in indoor environments in the gaseous phase. Because of their potential or known hazardous properties for humans, the World Health Organization (WHO)-Europe provided some guidelines that may prevent several health risks. Indeed, some aldehydes, reported to be risky for humans, have been retired from the market, such as butylphenyl methylpropional (BMHCA). The purpose of this review is to summarize the most important aldehydes found indoors and outdoors and analyse in depth the toxicological aspects of these compounds, whose presence in perfumes is often underestimated. In addition, the ingredients’ synonyms that are reported in the literature for the same compound were unified in order to simplify their identification. Full article

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17 pages, 1883 KB

Open AccessEditor’s ChoiceReview

Polycyclic Tetramate Macrolactams and Their Potential as Anticancer Agents

by Alexandria Montavon, M. Raquel Marchán-Rivadeneira and Yong Han

Organics 2024, 5(4), 361-377; https://doi.org/10.3390/org5040019 - 27 Sep 2024

Cited by 1 | Viewed by 3367

Abstract

Natural products have been a reliable source of drug compounds in medical research. Technological advances have led to the discovery and characterization of many compounds that were previously difficult to isolate. However, when searching for anticancer drugs, finding natural compounds that can bind [...] Read more.

Natural products have been a reliable source of drug compounds in medical research. Technological advances have led to the discovery and characterization of many compounds that were previously difficult to isolate. However, when searching for anticancer drugs, finding natural compounds that can bind to specific targets is a daunting task. Polycyclic tetramate macrolactams (PoTeMs), specifically, have been a source of antibiotics for a long time, though they possess certain cytotoxic properties that make them attractive candidates for anticancer drug discovery. This review covers the structural diversity and widespread availability of PoTeM compounds and the past research that demonstrates their effects on human cancer cell lines. Additionally, this review documents the known receptors and molecular mechanisms of these compounds in mammalian cells. Full article

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13 pages, 5316 KB

Open AccessEditor’s ChoiceReview

The Use of Heterocyclic Azo Dyes on Different Textile Materials: A Review

by Lucia Emanuele and Maurizio D’Auria

Organics 2024, 5(3), 277-289; https://doi.org/10.3390/org5030015 - 20 Aug 2024

Cited by 10 | Viewed by 4847

Abstract

The art of dyeing textiles has a long history, as natural dyes have been used since prehistoric times. With the development of synthetic dyes in the 19th century, the focus shifted from natural to synthetic dyes due to their superior properties. Recently, however, [...] Read more.

The art of dyeing textiles has a long history, as natural dyes have been used since prehistoric times. With the development of synthetic dyes in the 19th century, the focus shifted from natural to synthetic dyes due to their superior properties. Recently, however, interest in natural dyes has increased again due to environmental and health concerns. Among industrial dyes, heterocyclic dyes, especially azo dyes, are of great importance due to their color brilliance and fastness. This review examines the synthesis, application, and analysis of azo dyes, especially heterocyclic dyes. It deals with monoazo, diazo, and polyazo dyes and highlights their structures, synthesis methods, and fastness properties. In addition, the ecological impact of azo dyes and practical solutions for their synthesis and application are discussed. Full article

(This article belongs to the Special Issue Chemistry of Heterocyclic Compounds)

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14 pages, 1252 KB

Open AccessEditor’s ChoiceArticle

Aromatic Functionalized Indanones and Indanols: Broad Spectrum Intermediates for Drug Candidate Diversification

by Thomas C. Nugent and Nilesh N. Shitole

Organics 2024, 5(3), 263-276; https://doi.org/10.3390/org5030014 - 1 Aug 2024

Viewed by 2998

Abstract

A series of new aromatic substituted indanone and indanol building blocks have been prepared and are anticipated to aid future drug discovery studies. In total, seven compounds (7, 12–17) are expounded on, and all have been fully characterized. [...] Read more.

A series of new aromatic substituted indanone and indanol building blocks have been prepared and are anticipated to aid future drug discovery studies. In total, seven compounds (7, 12–17) are expounded on, and all have been fully characterized. In doing so, we have shown multiple examples of highly chemoselective reactions. One example employed an adaptation of Fujioka’s chemoselective reduction methodology, allowing an ester to be reduced in the presence of a ketone. In another example, an uncommon benzylic methyl group to aldehyde oxidation was demonstrated for two different compounds. These and other chemoselective interconversions allowed us to identify compound (12) as a remarkably flexible springboard for accessing a diverse array of indan-based building blocks (13–17). Full article

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42 pages, 29305 KB

Open AccessEditor’s ChoiceReview

Chiral Nonaromatic Nitrogen-Heterocycles by Asymmetric Intramolecular Haloamination and Haloamidation

by Mario Orena and Samuele Rinaldi

Organics 2024, 5(3), 163-204; https://doi.org/10.3390/org5030009 - 2 Jul 2024

Cited by 1 | Viewed by 2296

Abstract

This review deals with the functionalization of double bonds carried out in the presence of a chiral catalyst exploiting the intramolecular attack to haliranium ions by nucleophilic nitrogen of amides or carbamates prepared from achiral aminoalkenes, and the C–N bonds formation leads to [...] Read more.

This review deals with the functionalization of double bonds carried out in the presence of a chiral catalyst exploiting the intramolecular attack to haliranium ions by nucleophilic nitrogen of amides or carbamates prepared from achiral aminoalkenes, and the C–N bonds formation leads to highly enantioenriched nonaromatic heterocycles. A range of protocols are reported, emphasizing the synthesis of many natural and biologically active products of pharmacological interest prepared according to this methodology. Full article

(This article belongs to the Special Issue Heterocyclic Compounds and Their Derivatives: Synthesis and Applications)

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40 pages, 29528 KB

Open AccessEditor’s ChoiceReview

How Much Potential Do Nucleoside Analogs Offer to Combat Human Corona Viruses?

by Włodzimierz Buchowicz and Mariola Koszytkowska-Stawińska

Organics 2024, 5(2), 71-110; https://doi.org/10.3390/org5020006 - 8 May 2024

Cited by 2 | Viewed by 3614

Abstract

Nucleoside analogs (NAs) have been extensively examined as plausible antiviral agents in recent years, in particular since the outbreak of the global pandemic of COVID-19 in 2019. In this review, the structures and antiviral properties of over 450 NAs are collected according to [...] Read more.

Nucleoside analogs (NAs) have been extensively examined as plausible antiviral agents in recent years, in particular since the outbreak of the global pandemic of COVID-19 in 2019. In this review, the structures and antiviral properties of over 450 NAs are collected according to the type of virus, namely SARS-CoV, SARS-CoV-2, MERS-CoV, HCoV-OC43, HCoV-229E, and HCoV-NL63. The activity of the NAs against HCoV-related enzymes is also presented. Selected studies dealing with the mode of action of the NAs are discussed in detail. The repurposing of known NAs appears to be the most extensively investigated scientific approach towards efficacious anti-HCoV agents. The recently reported de novo-designed NAs seem to open up additional approaches to new drug candidates. Full article

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12 pages, 3310 KB

Open AccessEditor’s ChoiceArticle

Innovative Application of Polyether Amine as a Recyclable Catalyst in Aerobic Thiophenol Oxidation

by Lingxia Chen, Junyu Li, Ke Ni, Xinshu Qin, Lijun Wang, Jiaman Hou, Chao Wang, Xuan Li, Minlong Wang and Jie An

Organics 2024, 5(2), 59-70; https://doi.org/10.3390/org5020005 - 26 Apr 2024

Cited by 1 | Viewed by 2350

Abstract

Polyether amines are versatile compounds characterized by a flexible structure, consisting of polyoxypropylene and polyoxyethylene as the backbone, with amine groups at each end. They have widespread applications in various industrial processes and daily life. Despite their versatility, the utilization of polyether amines [...] Read more.

Polyether amines are versatile compounds characterized by a flexible structure, consisting of polyoxypropylene and polyoxyethylene as the backbone, with amine groups at each end. They have widespread applications in various industrial processes and daily life. Despite their versatility, the utilization of polyether amines as base catalysts is rare. In this study, one kind of three-arm polyether amine 1 was employed as an environmentally friendly, cost-effective catalyst for the aerobic oxidation of thiophenols, leading to the synthesis of disulfides. The oxidative coupling of thiols serves as a fundamental pathway for the production of disulfides, which are vital in both chemical and biological processes. In contrast to known methods for thiol oxidation, this polyether amine-based catalytic process eliminates the need for expensive stoichiometric oxidants and minimizes the formation of over-oxidized by-products. Using a mere 0.5 mol % of the polyether amine 1 as the catalyst, a remarkable > 96% yield was achieved for all 16 tested substrates, encompassing a diverse range of functional groups, under the catalytic aerobic oxidation conditions. Furthermore, it is noteworthy that over 90% of the polyether amine catalyst can be efficiently recovered for reuse without loss of activity, making this a sustainable and cost-effective catalytic approach. Full article

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20 pages, 2705 KB

Open AccessEditor’s ChoiceArticle

Synthesis and Butyllithium-Induced Cyclisation of 2-Benzyloxyphenylphosphonamidates Giving 2,3-Dihydrobenzo[d][1,3]oxaphospholes

by R. Alan Aitken, Khadija Ait Moulay, David B. Cordes, Ryan A. Inwood, Fraser G. Jamieson, Alexander J. B. Nelson and Aidan P. McKay

Organics 2024, 5(1), 12-31; https://doi.org/10.3390/org5010002 - 1 Feb 2024

Cited by 1 | Viewed by 2264

Abstract

A series of fourteen O-ethyl-N-butylphenylphosphonamidates with benzyl ether substituents at the ortho position was prepared and fully characterised. Upon treatment with n-butyllithium in THF at RT, they underwent cyclisation in eight cases to give the novel 2,3-dihydrobenzo[d][1,3]oxaphospholes [...] Read more.

A series of fourteen O-ethyl-N-butylphenylphosphonamidates with benzyl ether substituents at the ortho position was prepared and fully characterised. Upon treatment with n-butyllithium in THF at RT, they underwent cyclisation in eight cases to give the novel 2,3-dihydrobenzo[d][1,3]oxaphospholes in moderate to low yield as a single diastereomer, for which the relative configuration was determined by X-ray diffraction in one case. Full article

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15 pages, 3217 KB

Open AccessEditor’s ChoiceReview

Synthesis of 2-Substituted Benzimidazole Derivatives as a Platform for the Development of UV Filters and Radical Scavengers in Sunscreens

by Kameliya K. Anichina and Nikolai I. Georgiev

Organics 2023, 4(4), 524-538; https://doi.org/10.3390/org4040036 - 28 Nov 2023

Cited by 6 | Viewed by 4378

Abstract

The modern trend in sunscreen products is towards the development of UV filters with multi-functional properties, to provide a broad shielding against ultraviolet radiation, antioxidant activity, and the prevention of skin cancer. Additionally, they should also be safe for humans as well as [...] Read more.

The modern trend in sunscreen products is towards the development of UV filters with multi-functional properties, to provide a broad shielding against ultraviolet radiation, antioxidant activity, and the prevention of skin cancer. Additionally, they should also be safe for humans as well as the environment. The benzimidazole heterocycle is a suitable platform for the development of such multifunctional molecules with potential application in cosmetic formulations, due to their ability to act as both UV protectors and reactive pharmacophores. This review presents for the first time the progress in the synthesis and optimization of benzimidazole compounds as UV sunscreen filters. The modifications to the substitution pattern of the lead compound and structure–activity relationships are discussed, as well as the synthetic approaches for the preparation of 2-substituted benzimidazoles. These aggregated data will be useful in future in the development of modern benzimidazole-based sunscreen. Full article

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31 pages, 13206 KB

Open AccessEditor’s ChoiceReview

Recent Advances in Application of Alkoxy Radical in Organic Synthesis

by Munsaf Ali, Shi Sewell, Juncheng Li and Ting Wang

Organics 2023, 4(4), 459-489; https://doi.org/10.3390/org4040033 - 28 Sep 2023

Cited by 6 | Viewed by 6988

Abstract

Alkoxy radicals have been identified as versatile intermediates in synthetic chemistry in the last few decades. Over the last decade, various catalytic processes for the in situ generation of alkoxy radicals have been explored, leading to the development of new synthetic methodologies based [...] Read more.

Alkoxy radicals have been identified as versatile intermediates in synthetic chemistry in the last few decades. Over the last decade, various catalytic processes for the in situ generation of alkoxy radicals have been explored, leading to the development of new synthetic methodologies based on alkoxy radicals. In this review, we provided a comprehensive review of recent developments in the utilization of alkoxy radicals in diverse organic transformations, natural product synthesis, and the late-stage modification of bioactive molecules through the implementation of the photoredox methodology. Full article

(This article belongs to the Special Issue Design and Development of New Organic Synthetic Methods and Techniques)

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22 pages, 2652 KB

Open AccessEditor’s ChoiceArticle

Synthesis and Biological Evaluation of Substituted Fused Dipyranoquinolinones

by Evangelia-Eirini N. Vlachou, Eleni Pontiki, Dimitra J. Hadjipavlou-Litina and Konstantinos E. Litinas

Organics 2023, 4(3), 364-385; https://doi.org/10.3390/org4030027 - 10 Jul 2023

Cited by 2 | Viewed by 2479

Abstract

New methyl-substituted, and diphenyl-substituted fused dipyranoquinolinones are prepared in excellent yields via the triple bond activation and 6-endo-dig cyclization of propargyloxycoumarin derivatives by gold nanoparticles supported on TiO₂ in chlorobenzene under microwave irradiation. In the absence of gold nanoparticles, the methyl-substituted propargyloxycoumarin [...] Read more.

New methyl-substituted, and diphenyl-substituted fused dipyranoquinolinones are prepared in excellent yields via the triple bond activation and 6-endo-dig cyclization of propargyloxycoumarin derivatives by gold nanoparticles supported on TiO₂ in chlorobenzene under microwave irradiation. In the absence of gold nanoparticles, the methyl-substituted propargyloxycoumarin derivatives resulted in fused furopyranoquinolinones through Claisen rearrangement and 5-exo-dig cyclization. The intermediate propargyloxy-fused pyridocoumarins are prepared by propargylation of the corresponding hydroxy-fused pyridocoumarins. The methyl-substituted derivatives of the latter are synthesized in excellent yield by the three-component reaction of amino hydroxycoumarin with n-butyl vinyl ether under iodine catalysis. The diphenyl-substituted derivatives of hydroxy-fused pyridocoumarins are obtained, also, by the three-component reaction of amino hydroxycoumarin with benzaldehyde and phenyl acetylene catalyzed by iron (III) chloride. Preliminary biological tests of the title compounds indicated lipoxygenase (LOX) (EC 1.13.11.12) inhibitory activity (60–100 μM), whereas compound 28a, with IC₅₀ = 10 μM, was found to be a potent LOX inhibitor and a possible lead compound. Only compounds 10b and 28b significantly inhibited lipid peroxidation. Full article

(This article belongs to the Collection Advanced Research Papers in Organics)

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9 pages, 3225 KB

Open AccessEditor’s ChoiceCommunication

A New Rapid and Specific Iodination Reagent for Phenolic Compounds

by Till Hauenschild and Dariush Hinderberger

Organics 2023, 4(2), 137-145; https://doi.org/10.3390/org4020011 - 4 Apr 2023

Cited by 1 | Viewed by 3446

Abstract

A new rapid iodination reagent, N¹,N³,N⁵-tris[(2,4,6-trimethylpyridine)iodo(I)]-2,4,6-triphenyl-s-triazine trihexafluorophosphate, was synthesized in a modification of the established synthesis of 2,4,6-triiodo-3,5-dimethylphenol in the presence of bis(2,4,6-trimethylpyridine)iodo(I) hexafluorophosphate and used for the precise post-modification of mono- and trisubstituted [...] Read more.

A new rapid iodination reagent, N¹,N³,N⁵-tris[(2,4,6-trimethylpyridine)iodo(I)]-2,4,6-triphenyl-s-triazine trihexafluorophosphate, was synthesized in a modification of the established synthesis of 2,4,6-triiodo-3,5-dimethylphenol in the presence of bis(2,4,6-trimethylpyridine)iodo(I) hexafluorophosphate and used for the precise post-modification of mono- and trisubstituted phenyl compounds. We performed triple iodinations with our new phenyl-based compounds as a proof of principle of selected types of phenols, ß-sympatholytic agents and their spin-labeled derivatives, which can be employed in electron paramagnetic resonance (EPR) spectroscopy. The new rapid iodination reagent can be employed with high reactivity and regioselectivity. Full article

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17 pages, 2780 KB

Open AccessEditor’s ChoiceArticle

Triple Benefits of Cardanol as Chain Stopper, Flame Retardant and Reactive Diluent for Greener Alkyd Coating

by Maxinne Denis, Cédric Totée, Damien Le Borgne, Rodolphe Sonnier, Sylvain Caillol and Claire Negrell

Organics 2023, 4(1), 109-125; https://doi.org/10.3390/org4010009 - 15 Mar 2023

Cited by 6 | Viewed by 3509

Abstract

Cardanol, a waste from the food industry and widely produced (1 Mt/y), has been used as a chain stopper during the polycondensation of short oil alkyd resins in order to replace benzoic acid. Then, phosphorylated cardanol has been added in order to both [...] Read more.

Cardanol, a waste from the food industry and widely produced (1 Mt/y), has been used as a chain stopper during the polycondensation of short oil alkyd resins in order to replace benzoic acid. Then, phosphorylated cardanol has been added in order to both reduce solvent content and bring flame-retardant (FR) properties to the alkyd resins. The renewable carbon content of the formulations has been increased up to 23%. The impact of the introduction of phosphorylated cardanol molecules on the drying time and flexibility has been studied as well as the thermal and flame-retardant properties by differential scanning calorimeter, thermogravimetric analysis and pyrolysis-combustion flow calorimeter. The most effective flame-retardant coating that was associated with excellent FR properties and excellent coating properties has been obtained with phosphate-cardanol added at 2%wt of P. Indeed, the film properties were closed to the classical alkyd resin, the solvent content was reduced by 50% and the pHRR decreased by 42% compared to the reference alkyd resin. Full article

(This article belongs to the Special Issue Progress in Synthesis and Applications of Phosphorus-Containing Compounds)

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11 pages, 1031 KB

Open AccessEditor’s ChoiceArticle

Synthesis and Wittig Rearrangement of 3- and 4-Benzyloxyphenylphosphonamidates

by R. Alan Aitken and Ryan A. Inwood

Organics 2023, 4(1), 59-69; https://doi.org/10.3390/org4010005 - 3 Feb 2023

Cited by 4 | Viewed by 4161

Abstract

A series of seven O-ethyl-N-butylphenylphosphonamidates with benzyl ether substituents at the para or meta position have been prepared and fully characterised. Upon treatment with n-butyllithium in THF at RT, these undergo Wittig rearrangement in six cases to give the [...] Read more.

A series of seven O-ethyl-N-butylphenylphosphonamidates with benzyl ether substituents at the para or meta position have been prepared and fully characterised. Upon treatment with n-butyllithium in THF at RT, these undergo Wittig rearrangement in six cases to give the novel phosphonamidate-substituted diarylmethanols in moderate to good yield. Full article

(This article belongs to the Special Issue Progress in Synthesis and Applications of Phosphorus-Containing Compounds)

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8 pages, 1364 KB

Open AccessEditor’s ChoiceCommunication

Parallel Synthesis of Aurones Using a Homogeneous Scavenger

by Zachary E. Taylor and Scott T. Handy

Organics 2023, 4(1), 51-58; https://doi.org/10.3390/org4010004 - 28 Jan 2023

Cited by 2 | Viewed by 3671

Abstract

The ability to synthesize arrays of related compounds quickly and with good purity has become critical for a rapid exploration of their properties for biological or material applications. While a number of methods have been developed to enable this combinatorial synthesis, the existing [...] Read more.

The ability to synthesize arrays of related compounds quickly and with good purity has become critical for a rapid exploration of their properties for biological or material applications. While a number of methods have been developed to enable this combinatorial synthesis, the existing options were not readily appliable to the synthesis of aurones using the simple Knoevenagel condensation approach. In order to avoid the time, expense, and lowered yields associated with flash column chromatography, we developed a scavenging approach for their synthesis. This method uses an excess of aldehyde to ensure complete conversion to aurones, followed by selective removal of the remaining aldehyde using a simple, inexpensive scavenger – isoniazid – and subsequent extraction with dilute acid, to produce the desired compounds with good purity under operationally simple conditions. This approach is expected to be applicable to many other reactions involving aldehydes as one of the reactants. Full article

(This article belongs to the Collection Advanced Research Papers in Organics)

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