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

Abstract

The ruthenium-hydride complex (PCy3)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.