Selective oxidation of phenol and anisole derivatives to quinones with hydrogen peroxide and polymer-supported methylrhenium trioxide systems

A convenient and efficient application of heterogeneous poly(4-vinylpyridine)/methyl rhenium trioxide (PVP/MTO) systems for the selective oxidation of substituted phenol and anisole derivatives to benzoquinones is described. Environment friendly, easily available, and low cost H2O2 was used as the oxygen atom donor. All catalysts were stable systems for at least five recycling experiments. In the oxidation of some natural phenols such as cardanol derivatives higher conversion and yields of benzoquinones were observed with respect to MTO in homogeneous phase suggesting a support-mediated molecular recognition process based on hydrogen-bonding interactions.