Effective Oxidation of Alcohols under Heterogeneous Conditions with a New Reagent: Manganese Dioxide Supported on Graphite

A new reagent, manganese dioxide supported on graphite, under heterogeneous conditions at reflux is described for the oxidation of benzylic and allylic alcohols into the corresponding aldehydes and ketones, respectively. The main advantage of the present oxidation is that the insoluble solid support, graphite, provides a particular reaction environment capable of enhancing the reaction selectivity and reactivity. Moreover, it turns out to be very profitable in the workup, which becomes reduced to a mere filtration. The mechanism for this oxidation is also discussed.