Synthesis of novel fused 4,5-dihydro-1,2,3-triazolo[1,5-a][1,4]benzodiazepine derivatives via four-component Ugi–Smiles-type reaction

Strain-promoted azide-alkyne cycloaddition enhanced by secondary interactions

Azide-alkyne cycloaddition of cyclooct-2-yn-1-ol and 2-(azidophenyl)boronic acid proceeded rapidly at room temperature with complete regioselectivity to afford a triazole having a boronate ester group. The secondary interaction to form a boronate ion contributed to cycloaddition rate acceleration and the control of regioselectivity. The interaction to form an imine or hemiaminal was also evaluated.

Intramolecular Click Cycloaddition Reactions: Synthesis of 1,2,3-Triazoles

Click Chemistry, as a powerful tool, has been used for the synthesis of a variety of 1,2,3-triazoles. Among click cycloaddition reactions, intramolecular click reactions carried out in azido-alkyne precursors has not been thoroughly reviewed. Hence, in this review, we have summarized and categorised the recent literature (from 2012 on) based on the azidoalkynyl precursor's type and a brief and concise description of the involved mechanisms is presented. Accordingly, we have classified the relevant literature into three categories: (1) substitution precursors (2) addition and (3) multi-component reaction (MCR) products.

Growing Impact of Intramolecular Click Chemistry in Organic Synthesis

Click Chemistry, a modular, rapid, and one of the most reliable tool for the regioselective 1,2,3-triazole forming [3+2] reaction of organic azide and terimal alkyne is widely explored in various emerging domains of research ranging from chemical biology to catalysis and medicinal chemistry to material science. This regioselective reaction from a diverse range of azido-alkyne scaffolds has been well performed in both intermolecular as well as intramolecular fashions. In comparison to the intermolecular metal (Cu/Ru/Ni) variant of 'Click Chemistry', the intramolecular click tool is little addressed. The intramolecular click chemistry is exemplified as a mordern tool of cyclization which involves metal-catalyzed (CuAAC/RuAAC) cyclization, organo-catalyzed cyclization, and thermal-induced topochemical reaction. Thus, we report herein the recent approaches on intramolecular azide-alkyne cycloaddition 'Click Chemistry' with their wide-spread emerging applications in the developement of a diverse range of molecules including fused-heterocycles, well-defined peptidomemics, and macrocyclic architectures of various notable features.

Multicomponent cyclization with azides to synthesize N-heterocycles

Heterocyclic compounds, both naturally derived and synthetically produced, constitute a wide variety of biologically active and industrially important compounds. The synthesis and application of heterocyclic compounds have garnered significant attention and experienced rapid growth in recent decades. Organic azides, due to their unique properties and distinctive reactivity, have become a convenient chemical tool for achieving a wide range of heterocycles such as triazoles and tetrazoles. Importantly, the field of multicomponent reaction (MCR) chemistry provides a convergent approach to access various N-heterocyclic scaffolds, offering novelty, diversity, and complexity. However, the exploration of MCR pathways to N-heterocyclic compounds remains incomplete. Here, we review the use of multicomponent reactions for the preparation of N-heterocycles. A wide range of reactions based on azides for the synthesis of various types of N-heterocyclic systems have been developed.

Advances in the Synthesis of Fused 1,2,3-Triazoles via a MCR-Intramolecular Azide-Alkyne Cycloaddition Approach

The present review narrates several reports which deal with the synthesis of fused 1,2,3-triazole containing scaffolds following a sequential multicomponent reaction (MCR)-intramolecular azide-alkyne cycloaddition (IAAC) approach. The reviewed reactions were cleverly designed so as to incorporate azide and alkyne functionalities in the MCR product which was then subjected to IAAC. The review is divided into two sections based on the number of components in the multicomponent reaction. We have aimed at a critical discussion and also have highlighted either advantages or disadvantages of each methodology.

Regioselective One-Pot Synthesis, Biological Activity and Molecular Docking Studies of Novel Conjugates N-(p-Aryltriazolyl)-1,5-benzodiazepin-2-ones as Potent Antibacterial and Antifungal Agents

Novel 1,2,3-triazolo-linked-1,5-benzodiazepinones were designed and synthesized via a Cu(I)-catalyzed 1,3-dipolar alkyne-azide coupling reaction (CuAAC). The chemical structures of these compounds were confirmed by 1H NMR, 13C NMR, HMBC, HRMS, and elemental analysis. The compounds were screened for their in vitro antibacterial and antifungal activities. Several compounds exhibited good to moderate activities compared to those of established standard drugs. Furthermore, the binding interactions of these active analogs were confirmed through molecular docking.

Multicomponent reactions as a potent tool for the synthesis of benzodiazepines

Benzodiazepines (BZDs), a diverse class of benzofused seven-membered N-heterocycles, display essential pharmacological properties and play vital roles in some biochemical processes. They have mainly been prescribed as potential therapeutic agents, which interestingly represent various biological activities such as anticancer, anxiolytic, antipsychotic, anticonvulsant, antituberculosis, muscle relaxant, and antimicrobial activities. The extensive biological activities of BZDs in various fields have encouraged medicinal chemists to discover and design novel BZD-based scaffolds as potential therapeutic candidates with the favorite biological activity through an efficient protocol. Although certainly valuable and important, conventional synthetic routes to these bicyclic benzene compounds contain methodologies often requiring multistep procedures, which suffer from waste materials generation and lack of sustainability. By contrast, multicomponent reactions (MCRs) have recently advanced as a green synthetic strategy for synthesizing BZDs with the desired scope. In this regard, MCRs, especially Ugi and Ugi-type reactions, efficiently and conveniently supply various complex synthons, which can easily be converted to the BZDs via suitable post-transformations. Also, MCRs, especially Mannich-type reactions, provide speedy and economic approaches for the one-pot and one-step synthesis of BZDs. As a result, various functionalized-BZDs have been achieved by developing mild, efficient, and high-yielding MCR protocols. This review covers all aspects of the synthesis of BZDs with a particular focus on the MCRs as well as the mechanism chemistry of synthetic protocols. The present manuscript opens a new avenue for organic, medicinal, and industrial chemists to design safe, environmentally benign, and economical methods for the synthesis of new and known BZDs.

The status of isocyanide-based multi-component reactions in Iran (2010-2018)

Isocyanides as key intermediates and magic reactants have been widely applied in organic reactions for direct access to a broad spectrum of remarkable organic compounds. Although the history of these magical compounds dates back more than 100 years, it still has been drawing widespread attention of chemists who confirmed their versatility and effectiveness. Because of their wide spectrum of pharmacological, industrial and synthetic applications, many reactions with the utilization of isocyanides are reported in the literature. In this context, Iranian scientist played a significant role in the growth of isocyanides chemistry. The present review article covers literature from the period starting from 2010 onward and encompasses new synthetic routes and organic transformation involving isocyanides by Iranian researchers. During this period, a diverse range of isocyanide-based multi-component reactions (I-MCRs) has been reported such as a new modification of Ugi, post-Ugi, Passerini and Groebke-Blackburn-Bienayme condensation reactions, isocyanide-based [1 + 4] cycloaddition reactions, isocyanide-acetylene-based MCRs, isocyanide and Meldrum's acid-based MCRs, several unexpected reactions besides green mediums and novel catalytic systems for the synthesis of diverse kinds of pharmaceutically and industrially remarkable heterocyclic and linear organic compounds. This review also emphasizes the neoteric applications of I-MCR for the synthesis of valuable peptide and pseudopeptide scaffolds, enzyme immobilization and functionalization of materials with tailorable properties that can play important roles in the plethora of applications.

A simple one-pot synthesis of 2,4-diaryl- 9H-pyrido[2,3-b]indoles under solvent-free conditions

A novel, simple, one-pot synthesis of 2,4-diaryl-9

Synthesis of novel fused quinazolinone derivatives

A four-step synthetic route was developed for the synthesis of novel fused quinazolinones, quinazolino[3,4-a]quinazolinones, and isoinodolo[2,1-a]quinazolino[1,2-c]quinazolineones. Reaction of isatoic anhydride and different amines gave various 2-aminobenzamides. Then, reaction of 2-aminobenzamides with 2-nitrobenzaldehyde followed by the reduction of nitro group afforded 2-(2-aminophenyl)-3-aryl-2,3-dihydroquinazolin-4(1H)-one derivatives. Finally, reaction of the latter compounds with aromatic aldehydes or 2-formylbenzoic acid led to the formation of the corresponding products.

Synthesis and Evaluation of Novel Quinazolinone-1,2,3-Triazoles as Inhibitors of Lipoxygenase

This work reports the successful synthesis of quinazolinones carrying triazole derivatives with potent lipoxygenase inhibitory activities. This protocol involves sequential reactions affording novel products in high yields without the need for a tedious work-up procedure.

A Practical Approach for the Synthesis of Novel Triazolo-fused Benzazepine Derivatives Using a Multi-component Reaction and an Intramolecular C–H Arylation

An efficient and straightforward method has been developed for the preparation of triazolo-fused benzazepines by a facile, one-pot Ugi multi-component reaction/click reaction. In this strategy, the Ugi-reaction products were coupled by a click reaction, thus integrating the triazole fragment into the benzazepine structure using an intramolecular C–H arylation. The corresponding products were obtained in good yields without unfavourable by-products.

Copper supported β-cyclodextrin grafted magnetic nanoparticles as an efficient recyclable catalyst for one-pot synthesis of 1-benzyl-1H-1,2,3-triazoldibenzodiazepinone derivatives via click reaction

Cu immobilized into β-cyclodextrin covalently attached to magnetic nanoparticles (denoted as [Cu@β-CD@SPIONs]) is reported as an efficient and recoverable catalyst for “click” and multicomponent reactions.

A Highly Efficient Method for the Synthesis of Novel 1′H-spiro[indene-2,2′-quinazoline]-1,3,4′(3′H)-trione Derivatives

A Series of Novel Ninhydrin-derived Spiro-quinazolinone Derivatives in Moderate to Good Yields Have Been Synthesised Through a Ferric Chloride Catalysed Reaction in 1,2-dichloroethane.

Experimental and computational evidence for KOt-Bu-promoted synthesis of oxopyrazino[1,2-a]indoles

Metal-free intramolecular hydroamination of some Ugi adducts in the presence of KOt-Bu in DMF at room temperature led to the formation of novel oxopyrazino[1,2-a]indole derivatives.

Facile, novel and efficient synthesis of new pyrazolo[3,4-b]pyridine products from condensation of pyrazole-5-amine derivatives and activated carbonyl groups

A novel, simple and efficient route for the synthesis of new fused pyrazolo[3,4-b]pyridines is described.