Organics

18 pages, 4205 KiB

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 369

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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34 pages, 6479 KiB

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 4 | Viewed by 6896

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 KiB

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 1774

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 KiB

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 2 | Viewed by 2157

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 KiB

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 1608

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 KiB

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

Viewed by 1162

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 KiB

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

Viewed by 2100

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 KiB

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 1712

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 KiB

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 1485

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 KiB

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 2 | Viewed by 2720

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 KiB

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 2 | Viewed by 4829

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 KiB

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 1839

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 KiB

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 2335

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 KiB

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 4 | Viewed by 2690

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 KiB

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 2166

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 KiB

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 1 | Viewed by 2336

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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