The phenol ortho-oxygenation by mononuclear copper( I) complexes requires a dinuclear mu-eta(2) : eta(2)-peroxodicopper(II) complex rather than mononuclear CuO2 species

The mononuclear complex [Cu(L)](+) performs the ortho-oxygenation of an exogeneous phenol through the formation of a dinuclear mu-eta(2):eta(2)-peroxodicopper(II) intermediate, which is so far the only type of copper-dioxygen complex that mediates the tyrosinase monophenolase reaction.