General Synthesis of N-Alkylation of Amines with Secondary Alcohols via Hydrogen Autotransfer.

Direct catalytic N-alkylation of amines with secondary alcohols via hydrogen autotransfer (HA) strategy is very challenging and has been scarcely reported, even under precious metal catalysis. Herein, an efficient N-alkylation of amines, including benzylamines using secondary alcohols as alkylating agents, is reported. This reaction is catalyzed by a molecularly defined NNN-Ni(II) pincer complex, and the reaction operates under mild, benign conditions. Various substrates and functional groups were tolerated. Preliminary mechanistic studies suggest that the N-alkylation reaction proceeds via a hydrogen autotransfer mechanism.