Discovery of a practical direct O2-coupled Wacker oxidation with Pd[(-)-sparteine]Cl2.

The discovery of a direct O2-coupled Wacker oxidation with use of balloon pressure of O2 and low catalyst loading is described. Use of (-)-sparteine as a ligand on Pd prevents olefin isomerization and leads to selective formation of methyl ketones from terminal olefins in good yields. Oxidation of enantiomerically enriched substrates is reported with no observed racemization.