Aerobic oxidative coupling of alcohols and amines towards imine formation by a dicopper(I,I) catalyst

Abstract

A dicopper(I,I) complex [Cu2(L1) (Cl)2] (1), bearing a Cu2Cl2 core spanned by a naphthyridine–diimine ligand is synthesized by the treatment of CuCl with 2,7–bis(N–mesitylmethylimino)–1,8–naphthyridine (L1). The catalytic efficacy of 1 is assessed for aerobic oxidative synthesis of imines from alcohols and amines. The title complex is found to be an excellent catalyst for a wide variety of alcohols and amines. Kinetic experiments revealed the involvement of both copper ions in the aerobic oxidation process. The general utility of naphthyridine based ligands to favour a possible bimetallic pathway for a catalytic reaction is demonstrated here.