An efficient copper-catalysed aerobic oxybromination of arenes in water

An aerobic oxybromination of arenes catalysed by Cu(NO3)(2) was achieved using HBr as a bromine source, molecular oxygen as the oxidant and water as solvent with high selectivity. The catalyst shows not only high chemoselectivity for monobromination, but also a remarkable regioselectivity for para-isomers.