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

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.