Theoretical Studies onortho-Oxidation of Phenols with Dioxygen Mediated by Dicopper Complex: Hints for a Catalyst with the Phenolase Activity of Tyrosinase

Theoretical studies on the chemo- and regioselective ortho-oxidation reaction of phenols mediated by a biomimetic μ-η:η 2 peroxo)dicopper(II) complex were performed using unrestricted hybrid density functional theory (UB3LYP) calculations, with the aim of providing a guide for the development of new bio-inspired catalysts with the phenolase activity of tyrosinase. Energetic, structural, and electronic analyses suggested the involvement of a side-on (μ-η 2 :η 2 )-Cu 2 0 2 complex as an active intermediate, and a single electron transfer (SET)-induced electrophilic aromatic substitution mechanism is proposed for the rate-determining C-Ο bond forming process; this is consistent with experimental observations. Moreover, the inherent roles of, and requirement for, two copper ions in this reaction have been elucidated.