Palladium(II)-catalyzed oxidation of terminal alkenes to methyl ketones using molecular oxygen

Abstract

Palladium(II) acetate catalyzes the aerobic oxidation of terminal alkenes in toluene into the corresponding methyl ketones in the presence of a catalytic amount of pyridine using propan-2-ol as a reductant and molecular oxygen as an oxidant. Two catalytic cycles sharing a Pd(II)–OOH species are proposed. One is the formation of a Pd(II)–H species in the oxidation of propan-2-ol to acetone, followed by reaction with molecular oxygen to give a Pd(II)–OOH species, and the other is peroxypalladation of an alkene with the Pd(II)–OOH species produced to afford a methyl ketone in the presence of H₂O₂ produced by the former catalytic cycle.