Enantioselective synthesis of α-hydroxyphosphonates through asymmetric Pudovik reactions with chiral lanthanoid and titanium alkoxides

Abstract

The Pudovik reaction of aromatic aldehydes with diethyl phosphite catalysed by either tartrate-modified titanium(IV) alkoxides or binaphthol-modified lanthanoid alkoxides has been examined. The enantioselectivity for the Pudovik reaction catalysed by tartrate-modified titanium(IV) alkoxide 1 was strongly dependent upon the solvent used. The electronic nature of the carbonyl affected the enantioselectivity for the Pudovik reaction with the La-Li-BINOL complex 2.