Aerobic, chemoselective oxidation of alcohols to carbonyl compounds catalyzed by a DABCO-Copper complex under mild conditions

A DABCO-copper(l) chloride complex (5 mol %) together with TEMPO (5 mol %) in nitromethane as solvent has been used as an efficient catalytic system for the selective oxidation of benzylic and allylic alcohols into the corresponding carbonyl compounds at room temperature where molecular oxygen acts as an ultimate, stoichiometric oxidant and water is the only by-product. The solidstate structure determination of the DABCO-copper complex shows that the copper is in the +II oxidation state with trigonal bipyramidal geometry and exists in a linear polymeric structure due to strong hydrogen bonding.