Mechanism of aromatic hydroxylation in a copper monooxygenase model system. 1,2-methyl migrations and the NIH shift in copper chemistry

The mechanism of aromatic hydroxylation for 2-methyl substituted analogues of copper complexes studied previously, namely [Cu{sub 2}(Me{sub 2}XYL-CH{sub 3})]{sup 2+} (4) and [Cu{sub 2}(XYL-CH{sub 3})]{sup 2+} (5) are described in detail. Manometric O{sub 2} uptake experiments and labeling studies were used to unravel the reaction pathway. The NIH shift mechanism is said to be operative in a copper monooxygenase model system involving dicopper ion complex mediated O{sub 2} hydroxylation of an arene substrate. Manometric O{sub 2} uptake experiments and labeling studies were used to unravel the reaction pathway. 66 refs., 7 figs.