Discovery of and Mechanistic Insight into a Ligand-Modulated Palladium-Catalyzed Wacker Oxidation of Styrenes Using TBHP

We describe the discovery of a new N-heterocyclic carbene-modulated Pd catalyst for the Wacker oxidation that does not require molecular oxygen but instead uses TBHP as a reagent in this oxidation. The catalyst activity and selectivity for the oxidation of styrene derivatives to methyl ketones are among the best reported. Preliminary mechanistic studies of the catalytic system were performed and show that the origin of the carbonyl oxygen is TBHP and that the hydrogens in the product all originate from the starting olefin.