Switching Selectivity in Copper-Catalyzed Transfer Hydrogenation of Nitriles to Primary Amine-Boranes and Secondary Amines under Mild Conditions.

A simple and efficient copper-catalyzed selective transfer hydrogenation of nitriles to primary amine-boranes and secondary amines with an oxazaborolidine-BH complex is reported. The selectivity control was achieved under mild conditions by switching the solvent and the copper catalysts. More than 30 primary amine-boranes and 40 secondary amines were synthesized via this strategy in high selectivity and yields of up to 95%.