Aerobic Multicomponent Tandem Synthesis of 3-Sulfenylimidazo[1,2-a] pyridines from Ketones, 2-Aminopyridines, and Disulfides

An aerobic CeCl3 center dot 7H(2)O/NaI-catalyzed C-H functionalization reaction was developed for the synthesis of 3-sulfenylimidazo[1,2-alpha]pyridines from easily available ketones, 2-aminopyridines, and disulfides without DMSO or peroxide as an oxidant. This three-component tandem reaction process involves the formation of imidazo[1,2-alpha]pyridines followed by Friedel-Crafts sulfenylation in one pot under mild conditions. Both aryl and alkyl ketones afforded the desired products in good to excellent yields without the presence of other additives.