Synthesis of Six-Membered N-Heterocycles Using Ruthenium Catalysts

Facile one-pot, multi-component reaction to synthesize spirooxindole-annulated thiopyran derivatives under environmentally benevolent conditions

An efficient and facile one-pot, five-component reaction for the synthesis of 2,6-diamino-1-alkyl-2-oxospiro[indoline-3,4′-thiopyran]-3,5-dicarbonitrile derivatives has been reported by a reaction between primary amines, carbon disulfide, malononitrile, and isatin derivatives. The major advantages of this procedure are high yields of products in relatively short reaction time, scalability, mild conditions, multi-component synthetic procedure, low catalyst loading, no column separation and simple reaction work-up. As a consequence, this synthetic procedure provided an efficient access to spirooxindole-annulated thiopyran derivatives.

Nanocatalysts: applications for the synthesis of N-containing five-membered heterocycles

Using transition metals as nanocatalysts has opened up a vast new area in heterocyclic chemistry in the modern day. Heterocyclic moieties are significant scaffolds that have both pharmacological and industrial applications. Various scientific groups have focused their attention on the expansion of simple reaction protocols by introducing better functional group compatibilities under mild reaction conditions through the use of easily available starting materials. This review provides an outline of the applications of metallic nanoparticles as proficient, recyclable, low-cost and green heterogeneous catalysts for the preparation of a wide range of key therapeutic five-membered nitrogen-containing heterocyclic compounds as well as some other significant functionalizations over the rings. This review mainly covers the literature published through the period from 2004 to 2021.