Visible Light Mediated, Catalyst Free, One-Pot Convenient Synthesis of Dihydropyridines

A simple, efficient and green protocol has been developed for the synthesis of polysubstituted dihydropyridines via one-pot, four-component reaction of aldehydes, arylamines, dialkyl acetylenedicarboxylate, and malononitrile. The reaction was proceeded at room temperature in the absence of catalyst in aqueous ethyl lactate under visible light irradiation. The main advantages of the present approach are mild reaction conditions, high yield, no column chromatography, clean reaction profile, environmentally friendly and sustainability from the economic point of view.