An Fe3O4@P4VP@FeCl3 core–shell heterogeneous catalyst for aerobic oxidation of alcohols and benzylic oxidation reaction

Abstract

A novel magnetic Fe₃O₄@P4VP(poly(4-vinylpyridine))@FeCl₃ core–shell structure was successfully synthesized. Its Fe₃O₄@P4VP core was initially prepared via polymerization of 4-vinyl pyridine on the surface of Fe₃O₄ microspheres. The successful introduction of the FeCl₃ moiety as a catalytic active site was achieved through coordination interaction between P4VP and FeCl₃. The obtained Fe₃O₄@P4VP@FeCl₃ catalyst was applied in the selective oxidation of alcohols using molecular oxygen as the oxidant. It was shown that a variety of alcohol substrates is tolerated under optimized reaction conditions. Additionally, benzylic oxidation of hydrocarbon compounds was also evaluated using Fe₃O₄@P4VP@FeCl₃ as the catalyst and tBuOOH as the oxidant, achieving high yields and very good selectivities. The heterogeneity of the Fe₃O₄@P4VP@FeCl₃ core–shell catalyst was tested and the initial activity was maintained after five reuses.