Intermolecular Coupling Reaction of Cyclic Amines and Alkenes Catalyzed by a Ruthenium-Hydride Complex (PCy3)2(CO)RuHCl

The ruthenium-hydride complex (PCy 3 ) 2 (CO)RuHCl ( 1 ) was found to be an effective catalyst for the dehydrogenative coupling reaction of cyclic amines and alkenes. The reaction of secondary cyclic amines with unactivated alkenes preferentially gave the C−H bond insertion products in which both C−H and N−H bonds of amines have been selectively activated. In contrast, the reaction of amines with vinylsilane gave the N -silylation products. The catalytically active anionic ruthenium-amido complex was isolated from the reaction mixture, and its structure was established by X-ray crystallography. The preliminary mechanistic studies suggested that both C−H and N−H bond activation steps are mediated by a highly unsaturated ruthenium species.