Reductive generation of enolates from enones using elemental hydrogen: catalytic C-C bond formation under hydrogenative conditions.

Exposure of enones to elemental hydrogen in the presence of a Rh(I) catalyst enables reductive enolate generation, as evidenced by electrophilic trapping of the enolate by appendant and exogenous aldehyde partners. The significance of these findings resides in the ability to regioselectivity generate and transform transition metal enolates under catalytic conditions that circumvent formation of stoichiometric byproducts.