Copper Mediated Intramolecular vs. Intermolecular Oxygenations: The Spacer makes the Difference!

Copper complexes in combination with dioxygen are important as potential catalytic systems for regio- and stereoselective aerobic oxygenations of aromatic aliphatic C−H bonds at ambient temperatures. In that context we herein describe a copper(I) complex an imine ligand derived from (+)-camphor 2-(2-aminoethyl)pyridine forms bis(μ-hydroxido) dicopper upon reaction room temperature. It is detectable by UV-vis several hours up to few days, depending on the solvent could be structurally characterized. contrast previous observations this rather oxygenates acetone or thioanisole external substrates instead undergoing intramolecular hydroxylation.