A Facile Synthesis of 3-(Arylthio)imidazo[1,2-a]pyridin-2(3H)-ones from 2-Aminopyridinium Bromides and Sodium Arenesulfinates

Abstract

Direct C−H bond functionalization through radical pathway has emerged as a powerful and ideal strategy for the synthesis of organic compounds. This review provides an overview of recent developments in radical C−H functionalization of imidazoheterocycles such as imidazo[1,2-a]pyridine, benzo[d]imidazo[2,1-b]thiazole, imidazo[2,1-b]thiazole, imidazo[1,2-a]pyrimidine, imidazo[2,1-a]isoquinoline, imidazo[1,2-a]pyrazine and imidazo[1,2-a]quinoline using organic peroxides, photo/electric-induced protocols, iodine-based reagents, first-row transition metal catalysts (Fe, Mn, Ni and Cu) and inorganic oxidants/or salts.