Oxidative Coupling of Alcohols and Amines Using Functionalized Cu(II) 2-Quinoxolinol Salen Catalysts

Cu-(II) complexes bearing 2-quinoxolinol salen ligands have been prepared and studied for direct imine formation by oxidative coupling between alcohols and amines, with tert-butyl hydroperoxide (TBHP) as an oxidant under mild conditions. Various aromatic alcohols are coupled to anilines and benzylamines to form the corresponding imines in good-to-excellent yields. Notably, the water formed was the principal byproduct in 2 steps. This is a greener and more powerful approach as alcohols are readily accessible materials, enabling the synthesis of a diverse range of imine products.