Pseudo-Five-Component Reaction for Diastereoselective Synthesis of Butterfly Shaped Bispiro[Oxindole-Pyrrolidine]s

A pseudo-five-component reaction involving double decarboxylative 1,3-dipolar cycloaddition of azomethine ylides with olefinic oxindoles for the diastereoselective synthesis of bispiro[oxindole-pyrrolidine]s is developed. The major diastereomers are unique butterfly shaped compounds with a plane of symmetry. Recyclable zeolite HY acid catalyst is used to promote the reaction, and only CO₂ and H₂O are generated as byproducts.

Condensation-Based Methods for the C-H Bond Functionalization of Amines

This review aims to provide a comprehensive overview of condensation-based methods for the C-H bond functionalization of amines that feature azomethine ylides as key intermediates. These transformations are typically redox-neutral and share common attributes with classic name reactions such as the Strecker, Mannich, Friedel-Crafts, Pictet-Spengler, and Kabachnik-Fields reaction, while incorporating a redox-isomerization step. This approach provides an ideal platform to rapidly transform simple starting materials into complex amines.

Co2(CO)8 as a Solid CO (g) Source for the Amino Carbonylation of (Hetero)aryl Halides with Highly Deactivated (Hetero)arylamines

Carbonylation of (hetero)aryl iodides/bromides with highly deactivated 2-aminopyridines using Pd-Co(CO)₄ bimetallic catalysis is accomplished. The use of Co₂(CO)₈ as a solid CO(g) source enhanced reaction rates observed when compared to CO(g), and excellent yields highlight the versatility of the developed protocol. A wide range of electronically and sterically demanding heterocyclic amines and (hetero)aryl iodides/bromides employed for this study resulted in excellent yields of amino carbonylated products. The developed methodology was further extended to synthesize Trypanosome brucie and luciferase inhibitors.

I2-Catalyzed transformation of o-aminobenzamide to o-ureidobenzonitrile using isothiocyanates

The present work describes an unexpected and unique protocol for the iodine catalysed synthesis of o-ureidobenzonitriles using o-aminobenzamides and isothiocyanates via intramolecular rearrangement. The metal-free route achieved here is insensitive to moisture and applicable to the synthesis of a wide variety of o-ureidobenzonitriles with excellent yields even in a scalable fashion.

Domino Transformations of Ene/Yne Tethered Salicylaldehyde Derivatives: Pluripotent Platforms for the Construction of High sp3 Content and Privileged Architectures

Diversity-oriented synthesis (DOS) has become a powerful synthetic tool that facilitates the construction of nature-inspired and privileged chemical space, particularly for sp³ -rich non-flat scaffolds, which are needed for phenotypic screening campaigns. These diverse compound collections led to the discovery of novel chemotypes that can modulate the protein function in underrepresented biological space. In this context, starting material-driven DOS is one of the most important tools used to build diverse compound libraries with rich stereochemical and scaffold diversity. To this end, ene/yne tethered salicylaldehyde derivatives have emerged as a pluripotent chemical platform, the products of which led to the construction of a privileged chemical space with significant biological activities. In this review, various domino transformations employing o-alkene/alkyne tethered aryl aldehyde/ketone platforms are described and discussed, with emphasis on the period from 2011 to date.

Synthesis of 7'-Arylidenespiro[indoline-3,1'-pyrrolizines] and 7'-Arylidenespiro[indene-2,1'-pyrrolizines] via [3 + 2] Cycloaddition and β-C-H Functionalized Pyrrolidine

The acetic acid catalyzed three-component reaction of pyrrolidine, aromatic aldehydes, and 3-arylideneoxindolin-2-ones in refluxing toluene afforded functionalized 7'-arylidenespiro[indoline-3,1'-pyrrolizines] in good yields and with high diastereoselectivity. The similar three-component reaction with 2-arylidene-1,3-indanediones also gave 7'-arylidenespiro[indene-2,1'-pyrrolizines] in good yields. However, the reaction with 3-phenacylideneoxindoles resulted in a mixture of spiro[indoline-3,1'-pyrrolizines] and 7'-arylidene-substituted spirooxindoles in moderate yields. The reaction mechanism included generation of azomethine ylides, β-C-H functionalization of pyrrolidine, and sequential [3 + 2] cycloaddition. The obtained spirooxindole derivatives were investigated by in vitro evaluation against mouse colon cancer cells CT26 and human liver cancer cells HepG2 by MTT assay.

Synthesis and antiproliferative efficiency of novel bis(imidazol-1-yl)vinyl-1,2,4-oxadiazoles

A new class of bis(imidazol)vinyl-1,2,4-oxadiazoles were synthesised and their anti-proliferative efficiency was tested against HCT116 and A549 cancer cell lines.

A novel approach for the synthesis of imidazo and triazolopyridines from dithioesters

Various imidazo- and triazolo-pyridines were synthesised by the intramolecular cyclization of pyridine 2-methylamine and dithioesters under mild conditions.

One-step approach for the synthesis of functionalized quinoxalines mediated by T3P®–DMSO or T3P® via a tandem oxidation–condensation or condensation reaction

An easy and efficient (T3P®)–DMSO or T3P® mediated oxidation–condensation or condensation reaction for the synthesis of quinoxalines from the different arrays of condensing partners and ortho-phenylene diamines (o-PDs) in one step has been reported.

Tandem approach for the synthesis of 3-sulfenylimidazo[1,5-a]pyridines from dithioesters

Iodine-mediated synthesis of 3-sulfenylimidazo[1,5-a]pyridines via C–H functionalization has been achieved using dithioesters, 2-methylaminopyridines and sulfonyl hydrazides.