Application of phthalocyanine complexes of Cu(II), Co(II), Ni(II), and Zn(II) as catalysts in the transfer hydrogenation of acetophenone and its derivatives

Abstract

In this study, tetra substituted metallophthalocyanines (M: Ni, Zn, Co, and Cu) containing imine and azo groups were synthesized using microwave irradiation. The structures of all complexes have been totally characterized via 1HNMR, 13CNMR, TGA/DTA, LC-MS/MS, elemental analysis, UV–Vis, FT-IR spectroscopy. The comparison of the catalytic features of phthalocyanine based on metals is also discussed briefly. These phthalocyanine-complexes were also used in the transfer hydrogenation (TH) of acetophenone derivatives in the existence of KOH, utilizing isoPrOH as a hydrogen source. Acetophenone compounds determined a TH of up to 99 % conversion. Copper phthalocyanines were first used as catalysts in transfer hydrogenation reactions. The Cu(II) complexes showed higher catalytic activity, converting up to 97 % at 1.0 mol% catalyst loading. Furthermore, we have discovered that the catalytic characteristics of this class of molecules are significantly influenced by both steric and electronic variables.