Co‐operative visible‐light and Cu/Cu2O@g‐C3N4 catalysis towards Hantzsch/Biginelli synthesis of dihydro‐pyridine/pyrimidine

Herein, Cu/Cu2O@g‐C3N4 catalyzed direct Hantzsch and Biginelli protocols are reported for the synthesis of 1,4‐dihydropyridines and 1,4‐dihydropyrimidines, respectively. The reactions were carried out in the presence of visible light at room temperature via sequential activation of 1,3‐diketones and cyclodehydration steps to afford the target products in good to excellent yield (84–97%). Salient features of the developed methodology are operational simplicity, mild reaction conditions, low catalyst loading, no use of column chromatography, and reusability of catalyst up to five times with no significant loss of catalytic activity. The Cu/Cu2O@g‐C3N4 catalyzed direct Hantzsch and Biginelli protocols are reported for the synthesis of 1,4‐dihyropyridines and 1,4‐dihyropyrimidines respectively in the presence of visible light at room temperature. The reaction involved sequential activation of 1,3‐diketones and cyclodehydration to afford the target products in good to excellent yield (84–97%).