Copper-catalyzed oxidative cleavage of carbon–carbon double bond of enol ethers with molecular oxygen

A novel Cdouble bond; length as m-dashC bond cleavage reaction of aromatic enol ethers (1) to give ketones (2) using molecular oxygen as oxidant is described. Among the examined catalysts (Cu(II), Pd(II), Ru(II), and H+), CuCl2 exhibited the highest activity. The reaction proceeded smoothly with several kinds of substrates.