A new hybrid porphyrin-heteropolyacid material: Synthesis, characterization and investigation as catalyst in Baeyer-Villiger oxidation. Synergistic effect

A new tetraphenylporphyrin-tungstophosphoric acid hybrid was synthesized and physico-chemically characterized by different techniques. This hybrid, its molybdenum analogue, tungstophosphoric and molybdophosphoric acids as well as their, Mn, Fe and Co salts were applied in Baeyer-Villiger oxidation of cyclohexanone to caprolactone with molecular oxygen. Due to the synergistic effect porphyrin-heteropolyacid hybrids exhibit similar catalytic activity as appropriate heteropoly salts and much higher activity than parent heteropolyacids. (C) 2015 Elsevier B.V. All rights reserved.