Preparation of Imines by Oxidative Coupling of Benzyl Alcohols with Amines Catalysed by Dicopper Complexes

Complexation of 2,7-bis(2-pyridyl)-1,8-naphthyridine (bpnp) with Cu2O in formic acid under aerobic conditions provided a dicopper complex [Cu-2(bpnp)(-OH)(HCOO)(3)] (1). This complex has been characterized by X-ray crystallographic and spectroscopic analysis. With O-2 as the oxidant, complex 1 is an efficient catalyst for the oxidative coupling of alcohols with amines or diamines, leading to the corresponding imines or diimines in good to excellent yields.