Homogeneous cobalt-catalyzed deoxygenative hydrogenation of amides to amines

Abstract

The first general and efficient cobalt-catalyzed deoxygenative hydrogenation of amides to amines is presented. The optimal catalytic system based on a combination of [Co(NTf₂)₂] and (p-anisyl)triphos (L3) in the presence of [Me₃SiOTf] as acidic co-catalyst facilitates the direct hydrogenation of a broad range of amides to the corresponding amines under mild conditions. A set of control experiments indicate that, after the initial reduction of the amide carboxylic group to the well-known hemiaminal intermediate, the reaction mainly proceeds through C–O bond cleavage though other pathways might be also involved to a minor extent.