Enantioselective Construction Of Tertiary C(Sp3)-P Bonds By Thiourea-Based Bifunctional Phosphonium Salt-Catalyzed Hydrophosphonylation Of Ketone Compounds

Asymmetric hydrophosphonylation of carbonyl compounds to generate a variety of optically pure quaternary alpha-hydroxy phosphonate molecules is herein described by thiourea-derived bifunctional phosphonium salt catalysis. This new synthetic protocol has an excellent functional group tolerance, and particularly both aromatic, heteroaromatic and aliphatic alpha-ketoesters and 1,2-diketones were readily transferred into phosphonate products in high yields (up to 99 %) with excellent enantioselectivities (up to 97 % ee). The mechanistic results suggested that both ion pair and hydrogen-bonding interactions were crucial in asymmetric induction.