One-Pot Synthesis of Indoles from Aniline and α,β-Ynones through an Iodine-Mediated Transition-Metal-Free Tandem aza-Michael addition/C-H Functionalization

An efficient iodine-mediated aza-Michael addition/C-H functionalization procedure for the synthesis of indoles was achieved in one pot. By simple aza-Michael addition between anilines and alpha,beta-ynones, a series of N-aryl enaminones intermediate was generated, followed by iodine-mediated C-H functionalization, a wide variety of indole derivatives were obtained in moderate to excellent yields under transition-metal-free conditions. Control experiments and insitu ESI-MS analysis indicated the reaction occurred via a radical mechanism.