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.