Oxidation of benzyl alcohol under a synergism of phase transfer catalysis and heteropolyacids

The use of heteropolyacids in conjunction with phase transfer catalysts in the oxidation of benzyl alcohol to benzaldehyde with hydrogen peroxide as t he oxidising agent has been investigated. The effect of various parameters on the conversion of benzyl alcohol was studied including the effect of the nature of the heteropolyanion as well as the effect of the partial substit ution of protons in the heteropolyacid. Surfactant-type phase transfer cata lysts were found to display high catalytic activity with cetyltrimethylammo nium bromide (CTMAB) being the most effective phase transfer catalyst among those examined. A suitable mechanism for this reaction has been proposed a nd a kinetic model has been developed in order to explain the observed expe rimental results. (C) 2001 Elsevier Science B.V. All rights reserved.