Copper(II)-catalyzed selective reduction of chalcones using phenylsilane

A copper-catalyst system for the chemoselective reduction of electronically diverse chalcones under mild reaction conditions is reported here. This straightforward method employs phenylsilane (PhSiH₃) as a mild hydride source, 4,5-diazafluoren-9-one (DAFO) as a ligand, and copper(II) acetate as the catalyst. The reduction was successfully applied to a range of chalcone derivatives containing both electron-donating (EDG) and electron-withdrawing (EWG) groups. Under optimized conditions, a broad scope of substrates was explored, yielding products in moderate to good yields. The sustainability of copper catalysis and the ease of applying this catalytic system make it an attractive alternative for selective alkene reductions in targeted organic synthesis.