Hydride-Mediated Homogeneous Catalysis. Catalytic Reduction of α,β-Unsaturated Ketones Using 6 and H2

Article abstract of DOI:10.1021/ja00206a008

Hydride-mediated reduction of α,β-unsaturated ketones catalytic in the hydride reagent is reported using <(Ph3P)CuH>6 and molecular hydrogen.The reaction proceeds at room temperature and is highly regioselective, affording either the product of conjugate reduction or complete 1,4- and 1,2-reduction to the saturated alcohol, depending on reaction conditions.In the presence of excess phosphine, the process is homogeneous and chemoselective: isolated double bonds are not hydrogenated, even under forcing conditions.This novel catalytic reduction appears to proceed viathe heterolytic activation of molecular hydrogen by highly reactive copper(I) enolate and alkoxide intermediates.