Ni-Catalyzed Enantioselective Intermolecular Hydroamination of Branched 1,3-Dienes Using Primary Aliphatic Amines

A Ni-catalyzed intermolecular enantioselective hydroamination of branched 1,3-dienes is reported. The method is broadly applicable, highly regio-, chemo-, and enantioselective, and provides direct access to valuable chiral allylic amines starting from linear or alpha-branched aliphatic primary amines or secondary amines. Mechanistic studies have been conducted using P-31 NMR spectroscopy for reaction progress monitoring, isotopic labeling experiments (H-2), and kinetic analysis. The resting state of the catalyst is a Ni-pi-allyl complex, and the outer-sphere nucleophilic attack of H-bonded amine aggregates is proposed to be the rate-determining step. This hypothesis guided the identification of an improved set of reaction conditions for the enantioselective hydroamination of branched 1,3-dienes.