OXIDATION OF ALKYLAROMATIC COMPOUNDS WITH HYDROGEN-PEROXIDE CATALYZED BY MIXED ADDENDA KEGGIN HETEROPOLYANIONS

Keggin type mixed addenda heteropolyanions containing vanadium atoms such as PV2Mo10O405- are shown to be effective catalysts for the oxidation of alkylaromatic compounds to the respective acetates or alcohols and aldehydes or ketones using 30% hydrogen peroxide as oxidant. Use of spectroscopic techniques including UV-Vis, IR, vanadium-51 and phosphorus-31 NMR, and ESR shows that the H5PV2Mo10O40 compound is not degraded during the catalytic cycle. Oxidation proceeds by homolytic cleavage of H5P2Mo10O40-peroxo intermediates. The resulting hydroperoxy and hydroxy radicals initiate the formation of benzyl radicals which lead to the product formation.