Unraveling the\nMetal–Ligand Cooperativity in\na Phosphine-Free Mn(II)-Catalyzed Transfer Hydrogenation of Nitriles\nto Primary Amines and Dehydrogenation of Dimethylamine Borane

Selective synthesis of primary amines from nitriles is\nchallenging\nin synthetic chemistry owing to the possible en route formation of\nvarious amines and imines. Herein, we report a well-defined phosphine-free\nMn(II)-pincer complex-catalyzed transfer hydrogenation of nitriles\nto the corresponding primary amines with a relatively unexplored hydrogen\nsource (dimethylamine borane). The protocol proceeds under relatively\nmild conditions with a broad substrate scope involving metal–ligand\ncooperation. Various control studies have been performed to understand\nthe mechanism of the present strategy. The gas chromatography analysis\nof the reaction mixture revealed the evolution of the H<sub>2</sub> gas through the dehydrogenation of dimethylamine borane. Detailed\ncomputational calculations were undertaken to shed light on the possible\nintermediates and transition states involved during the present protocol.