One-Pot Metal-Free Synthesis of [1,2,3]triazolo[1,5-a]-quinoxalines by Sequential Ugi-3CR/Alkyne-Azide Cycloaddition Reaction

A convenient and one-pot approach to prepare [1,2,3]triazolo[1,5-a]quinoxalin-4(5H)-ones by a metal-free sequential Ugi-4CR/alkyne–azide cycloaddition reaction has been developed. The reaction of 2-azidobenzenamines, aldehydes, propiolic acids, and isocyanides produced the Ugi adducts, which were transformed to the [1,2,3]triazolo[1,5-a]quinoxalin-4(5H)-ones in moderate to good yields via alkyne–azide cycloaddition reaction.

Download Full-text

An Expeditious Route for the Synthesis of Oxazepine Triazolo-β-Lactams through Intramolecular Metal-Free [3+2] Azide–Alkyne Cycloaddition

Australian Journal of Chemistry ◽

10.1071/ch19670 ◽

2020 ◽

Vol 73 (7) ◽

pp. 654

Author(s):

Ram N. Yadav ◽

Sunena Chandra ◽

Armando Paniagua ◽

Md. Firoj Hossain ◽

Bimal Krishna Banik

Keyword(s):

Sodium Azide ◽

Good Yield ◽

Cycloaddition Reaction ◽

Present Approach ◽

One Pot ◽

Metal Free ◽

Internal Alkynes

A copper-free intramolecular azide–alkyne cycloaddition reaction of 4-hydroxymethyl-β-lactam with sodium azide has been described. The present approach involves the incorporation of an alkyne moiety through O-alkynylation of 3-hydroxy β-lactam with various propargylic halides. The generality of the method has been demonstrated by treating the corresponding tosylates or mesylates of the hydroxymethyl functionality of a variety of β-lactam-tethered terminal and internal alkynes with sodium azide in a one-pot three-step reaction to furnish novel oxazepane-β-lactam fused triazole scaffolds of diverse interest in good yield.

Download Full-text

One-pot synthesized multi-functional graphene oxide as a water-tolerant and efficient metal-free heterogeneous catalyst for cycloaddition reaction

Carbon ◽

10.1016/j.carbon.2015.05.023 ◽

2015 ◽

Vol 93 ◽

pp. 22-31 ◽

Cited By ~ 73

Author(s):

Dong-Hui Lan ◽

Lang Chen ◽

Chak-Tong Au ◽

Shuang-Feng Yin

Keyword(s):

Graphene Oxide ◽

Heterogeneous Catalyst ◽

Cycloaddition Reaction ◽

One Pot ◽

Metal Free ◽

Functional Graphene Oxide

Download Full-text

Metal-Free Photoinduced Hydroalkylation Cascade Enabled by an Electron-Donor-Acceptor Complex

10.26434/chemrxiv.11912073 ◽

2020 ◽

Author(s):

José Tiago Menezes Correia ◽

Gustavo Piva da Silva ◽

Camila Menezes Kisukuri ◽

Elias André ◽

Bruno Pires ◽

...

Keyword(s):

Electron Donor ◽

Functional Group ◽

Photoexcited Electron ◽

One Pot ◽

Quaternary Centers ◽

Metal Free ◽

Acceptor Complex ◽

Catalyst Free ◽

Donor Acceptor ◽

Radical Cascade

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

Download Full-text

Metal-Free Photoredox-Catalyzed C–H/C–H Coupling of Arenes Enabled by Interrupted Pummerer Activation

10.26434/chemrxiv.9158564 ◽

2019 ◽

Author(s):

Miles Aukland ◽

Mindaugas Šiaučiulis ◽

Adam West ◽

Gregory Perry ◽

David Procter

Keyword(s):

Natural Product ◽

Selective Reduction ◽

Cross Coupling ◽

One Pot ◽

Complex Molecules ◽

Pummerer Reaction ◽

Metal Free ◽

Bond Forming ◽

Coupling Partner ◽

Bioactive Natural Product

<p>Aryl–aryl cross-coupling constitutes one of the most widely used procedures for the synthesis of high-value materials, ranging from pharmaceuticals to organic electronics and conducting polymers. The assembly of (hetero)biaryl scaffolds generally requires multiple steps; coupling partners must be functionalized before the key bond-forming event is considered. Thus, the development of selective C–H arylation processes in arenes, that side-step the need for prefunctionalized partners, is crucial for streamlining the construction of these key architectures. Here we report an expedient, one-pot assembly of (hetero)biaryl motifs using photocatalysis and two non-prefunctionalized arene partners. The approach is underpinned by the activation of a C–H bond in an arene coupling partner using the interrupted Pummerer reaction. A unique pairing of the organic photoredox catalyst and the intermediate dibenzothiophenium salts enables highly selective reduction in the presence of sensitive functionalities. The utility of the metal-free, one-pot strategy is exemplified by the synthesis of a bioactive natural product and the modification of complex molecules of societal importance.</p>

Download Full-text

Metal-Free Synthesis of 1,2,4-Triazines via a Coupled Domino Process in One-Pot

Current Organic Chemistry ◽

10.2174/1385272820666160919113406 ◽

2016 ◽

Vol 21 (2) ◽

pp. 183-188

Author(s):

Jing Wang ◽

Dong Tang ◽

Zhuo-Mei Li ◽

Ping Wu ◽

Xu Meng ◽

...

Keyword(s):

One Pot ◽

Metal Free

Download Full-text

Copper-catalyzed Convenient Synthesis and SAR Studies of Substituted-1,2,3-triazole as Antimicrobial Agents

Letters in Drug Design & Discovery ◽

10.2174/1570180815666180326153322 ◽

2018 ◽

Vol 16 (1) ◽

pp. 3-10

Author(s):

Aniket P. Sarkate ◽

Kshipra S. Karnik ◽

Pravin S. Wakte ◽

Ajinkya P. Sarkate ◽

Ashwini V. Izankar ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antifungal Activity ◽

Antimicrobial Agents ◽

Cycloaddition Reaction ◽

Dipolar Cycloaddition ◽

One Pot ◽

Triazole Derivatives ◽

Sar Studies ◽

Convenient Synthesis ◽

Antibacterial And Antifungal

Background:A novel copper-catalyzed synthesis of substituted-1,2,3-triazole derivatives has been developed and performed by Huisgen 1,3-dipolar cycloaddition reaction of azides with alkynes. The reaction is one-pot multicomponent.Objective:We state the advancement and execution of a methodology allowing for the synthesis of some new substituted 1,2,3-triazole analogues with antimicrobial activity.Methods:A series of triazole derivatives was synthesized by Huisgen 1,3-dipolar cycloaddition reaction of azides with alkynes. The structures of the synthesized compounds were elucidated and confirmed by 1H NMR, IR, MS and elemental analysis. All the synthesized compounds were tested for their antimicrobial activity against a series of strains of Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and against the strains of Candida albicans, Aspergillus flavus and Aspergillus nigar for antifungal activity, respectively.Results and Conclusion:From the antimicrobial data, it was observed that all the newly synthesized compounds showed good to moderate level of antibacterial and antifungal activity.

Download Full-text

Microwave-accelerated Carbon-carbon and Carbon-heteroatom Bond Formation via Multi-component Reactions: A Brief Overview

Current Microwave Chemistry ◽

10.2174/2213346107666200218124147 ◽

2020 ◽

Vol 7 (1) ◽

pp. 23-39 ◽

Cited By ~ 2

Author(s):

Kantharaju Kamanna ◽

Santosh Y. Khatavi

Keyword(s):

Organic Synthesis ◽

Bond Formation ◽

Cycloaddition Reaction ◽

Nanoparticle Synthesis ◽

Single Step ◽

Bioactive Molecules ◽

One Pot ◽

Bond Forming ◽

Material Interest ◽

Carbon Carbon Bond

Multi-Component Reactions (MCRs) have emerged as an excellent tool in organic chemistry for the synthesis of various bioactive molecules. Among these, one-pot MCRs are included, in which organic reactants react with domino in a single-step process. This has become an alternative platform for the organic chemists, because of their simple operation, less purification methods, no side product and faster reaction time. One of the important applications of the MCRs can be drawn in carbon- carbon (C-C) and carbon-heteroatom (C-X; X = N, O, S) bond formation, which is extensively used by the organic chemists to generate bioactive or useful material synthesis. Some of the key carbon- carbon bond forming reactions are Grignard, Wittig, Enolate alkylation, Aldol, Claisen condensation, Michael and more organic reactions. Alternatively, carbon-heteroatoms containing C-N, C-O, and C-S bond are also found more important and present in various heterocyclic compounds, which are of biological, pharmaceutical, and material interest. Thus, there is a clear scope for the discovery and development of cleaner reaction, faster reaction rate, atom economy and efficient one-pot synthesis for sustainable production of diverse and structurally complex organic molecules. Reactions that required hours to run completely in a conventional method can now be carried out within minutes. Thus, the application of microwave (MW) radiation in organic synthesis has become more promising considerable amount in resource-friendly and eco-friendly processes. The technique of microwaveassisted organic synthesis (MAOS) has successfully been employed in various material syntheses, such as transition metal-catalyzed cross-coupling, dipolar cycloaddition reaction, biomolecule synthesis, polymer formation, and the nanoparticle synthesis. The application of the microwave-technique in carbon-carbon and carbon-heteroatom bond formations via MCRs with major reported literature examples are discussed in this review.

Download Full-text

Synthesis of Pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by Alkyne-Carbonyl Metathesis

Synthesis ◽

10.1055/s-0040-1706105 ◽

2020 ◽

Author(s):

Peter Ehlers ◽

Peter Langer ◽

Marian Blanco Ponce ◽

Silvio Parpart ◽

Alexander Villinger ◽

...

Keyword(s):

Heterocyclic Compounds ◽

Metathesis Reaction ◽

Synthetic Methodology ◽

Facile Synthesis ◽

Reaction Conditions ◽

One Pot ◽

Metal Free ◽

Modular Synthesis

AbstractA concise and modular synthesis of pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by a one-pot two-step reaction consisting of electrophilic acylation followed by an alkyne-carbonyl-metathesis reaction as the final cyclization step is reported. This developed synthetic methodology allows the facile synthesis of these heterocyclic core structures in mainly high overall yields under metal-free conditions. Reaction conditions are carefully optimized and display a novel supplement to access these tricyclic heterocyclic compounds.

Download Full-text