Copper Complexes as Functional Models for Dopamine β-Hydroxylase – Stereospecific Oxygen Atom Transfer

Abstract

The stereochemistry of oxygen atom transfer mediated by copper–oxygen species has been studied through a substrate binding ligand approach. Copper(II) [(IndPY2)Cu](CF3SO3)2 (2a) and copper(I) [(IndPY2)Cu]PF6 (5a) complexes were prepared and exposed to O2 in media of benzoin/NEt3/CH2Cl2 and CH2Cl2, respectively. In both cases, highly regio- and stereoselective oxygen atom transfer to the benzylic C–H bond of the indane ligand occurred. Using deuterium-labelled copper complexes 2b and 5b, we found that, in both cases, the oxygen atom transfer occurs with retention of configuration. The high deuterium kinetic isotope effects (7.6 and 11, respectively), determined by 13C-NMR spectroscopy, strongly suggest the intermediacy of two different copper–oxygen reactive species.