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.

Automated summary

This study reports the Cu/Cu2O@g-C3N4 catalyzed direct synthesis of 1,4-dihydropyridines and 1,4-dihydropyrimidines using the Hantzsch and Biginelli protocols. The methodology offers operational simplicity, mild reaction conditions, low catalyst loading, no need for column chromatography, and reusability of the catalyst up to five times without significant loss of activity.