Metal-free, iodine-catalyzed regioselective sulfenylation of indoles with thiols

An iodine-catalyzed regioselective sulfenylation of indoles in the presence of DMSO has been presented. Various indoles can react with aryl thiols or alkyl thiols to afford their corresponding 3-sulfenylindoles in good to excellent yields. The notable features of this protocol include easy operation, metal-free reaction conditions, and excellent functional group tolerance.178