New Efficient Organic Activators for Highly Enantioselective Reduction of Aromatic Ketones by Trichlorosilane

Aryl ketones were reduced to the corresponding alcohols with excellent enantioselectivity (up to 99.7% ee) by Cl3SiH in the presence of a
catalytic amount of N-formyl-α‘-(2,4,6-triethylphenyl)-l-proline as an activator. Both carboxyl group at the α-position of the activator and
2,4,6-triethylphenyl group at the α‘-position were critical for the high enantioselectivity.