Kinetics and mechanism of the ferroxime(II)-catalysed biomimetic oxidation of 2-aminophenol by dioxygen. A functional phenoxazinone synthase model.

[Fe(Hdmg)(2)(MeIm)(2)](1), referred to as ferroxime(II), is the precursor of a selective catalyst for the oxidative dehydrogenation of 2-aminophenol (Hap) to 2-amino-3H-phenoxazine-3-one (apx) by dioxygen under ambient conditions. The superoxoferroxime(III) species has been detected by ES-MS, and a 4-substituted 2-aminophenoxyl free radical by the ESR technique. The kinetics of the reaction was followed spectrophotometrically and by monitoring dioxygen uptake at constant pressure.