Iron(III)-Catalyzed Cascade Reaction between Nitroolefins and 2-Aminopyridines: Synthesis of Imidazo[1,2-a]pyridines and Easy Access towards Zolimidine

The iron(III)-catalyzed one-pot cascade reaction between nitroolefins and 2-aminopyridines has been demonstrated for the synthesis of imidazo[1,2-a]pyridines by exploiting the bielectrophilic nature of nitroolefins. This methodology could be successfully applicable for the synthesis of zolimidine, a useful drug for the treatment of peptic ulcer. The reaction proceeds through Michael addition followed by intramolecular cyclization and in situ denitration.