Theoretical study of the hydroxylation of phenols mediated by an end-on bound superoxo copper(II) complex

Peptidylglycine α-amidating monooxygenase and dopamine β-monooxygenase are copper-containing proteins which catalyze essential hydroxylation reactions in biological systems. There are several possible mechanisms for the reductive O2-activation at their mononuclear copper active site. Recently, Karlin and coworkers reported on the reactivity of a copper(II)–superoxo complex which is capable of inducing the hydroxylation of phenols with incorporated oxygen atoms derived from the Cu(II)-O2 ·− moiety. In the present work the reaction mechanism for the abovementioned superoxo complex with phenols is studied. The pathways found are analyzed with the aim of providing some insight into the nature of the chemical and biological copper-promoted oxidative processes with 1:1 Cu(I)/O2-derived speciesFinancial help has been furnished by the Spanish Ministerio de Educación y Ciencia (MEC) projects No. CTQ2005-08797-C02-01/BQU and CTQ2008-03077/BQU and by the Catalan Department d’Universitats, Recerca i Societat de la Informació (DURSI) of the Generalitat de Catalunya project No. 2005SGR-0023