Enantioselective Conjugate Reduction of Unsaturated Nitriles

Significance

This is the first reported method for the asymmetric reduction of conjugated nitriles. The use of a bis-phosphine ligand (commercially available JosiPhos) allowed avoiding the inhibitory effect of the cyano group on the copper hydride catalyst activity. Very high yields and ee values are usually achieved in this reaction. Both regioisomers of the alkenyl nitrile can be involved in the process and lead to the products with the opposite absolute configuration.