Aerobic Oxygenation of Benzylic Ketones Promoted by a Gold Nanocluster Catalyst

Gold nanoclusters stabilized by poly(N-vinyl-2-pyrrolidone) (Au:PVP) promote the oxidation of benzylic ketones, including auto-oxidation-type bond-cleavage reactions and alpha-hydroxylation, under ambient conditions. The catalyst accelerates the formation of an alpha-peroxide intermediate, from which bond cleavage spontaneously proceeds in aqueous solvent to give the auto-oxidation products. In contrast, the alpha-hydroxylation product is obtained predominantly in DMSO solvent.