Asymmetric Hydrophosphination of Enals

Significance

Here Melchiorre and co-workers report an organocatalytic asymmetric hydrophosphination of α,β-unsaturated aldehydes. Enantioenriched β-phosphine aldehydes 4 were obtained and the corresponding alcohols 5 were isolated as air-stable products using the well-established chiral secondary amine catalyst 1. With 10-20 mol% of catalyst moderate to good yields (60-92%) and high enantioselectivities (75-94% ee) were obtained. This method can be applied to substrates with a wide range of enal substituents including aryl, heteroaryl, alkyl, and alkenyl groups.