Asymmetric Synthesis of α-Chiral Hydroxyalkylphosphines by a Catalytic Enantioselective Reduction of Acylphosphines

Enantioselective reduction of acylphosphines, after precomplexation with borane, proceeded smoothly in the presence of a chiral oxazaborolidine catalyst and catecholborane. α-Hydroxyalkylphosphine products were obtained as phosphine-borane complexes in good yield and enantioselectivity. One of the products of the enantioselective reduction was successfully applied as an optically active phosphine ligand for asymmetric catalysis after suitable derivatization.