New five- and six-coordinate complexes containing the [Mn-III(Br(4)cat)(2)](-) core (Br(4)cat(2-) = tetrabromo-1,2-catecholate) have been prepared. Homoleptic [Mn-III(Br(4)cat)(3)](3-) reacts rapidly with O-2 to produce tetrabromo-1,2-benzoquinone (Br(4)bq). The [Mn-III(Br(4)cat)(2)](-) fragment is a robust catalytic platform for the aerobic conversion of catechols to quinones. The oxidase activity apparently derives from the coupling of metal- and ligand-centered redox events.