Aromatic hydroxylation reactivity of a mononuclear Cu(II)-alkylperoxo complex

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