Aromatic Hydroxylation Reactivity of a Mononuclear Cu(II)−Alkylperoxo Complex

Reaction of copper(II) complex 1X supported by the tridentate bis(pyridylmethyl)amine ligand containing m-substituted phenyl groups at the 6-positions of the pyridine rings (LX) with H2O2 in the presence of triethylamine (NEt3) in acetone generates a copper(II)−alkylperoxo species 2X [2-hydroxy-2-hydroperoxypropane (HHPP) adduct]. The alkylperoxo intermediate 2X undergoes an efficient aromatic ligand hydroxylation reaction, producing a phenolate complex 4X via another intermediate 3X. Kinetic studies on the aromatic hydroxylation process are reported together with spectral characterization of 2X.