Catalytic oxidation of benzene by mononuclear copper(II) complexes with a bis(imidazolyl)methane ligand

Abstract

Catalytic oxidation of benzene under mild conditions is one of the most challenging reactions in synthetic chemistry. In order to develop a hydroxylation catalyst for benzene, we have designed and synthesized new copper(II) complexes with the bidentate ligand bis(1,4,5-trimethyl-2-imidazolyl)methane (Me₆bim), [Cu(Me₆bim)X₂] (X = Cl, Br). This ligand provides a reaction space which can be easily accessed by exogenous substrates and has an imidazole group, which is a typical ligand of metalloenzymes. These complexes exhibit catalytic oxidation of benzene in the presence of excess H₂O₂ at room temperature in aqueous MeCN solution to yield phenol and 1,4-benzoquinone.