Oxidation of cyclohexane catalyzed by bis-(2-pyridylmethyl)amine Cu(II) complexes

In this work, it is showed the cyclohexane oxidation catalyzed by the copper(II) complexes, [Cu(BMPA)Cl-2] (1) and {[Cu(BMPA)Cl-2] [Cu(BMPA)(H2O)Cl] [Cu(BMPA)Cl][CuCl4]} (2), using hydrogen peroxide or tert-butyl hydroperoxide as terminal oxidants and acetonitrile as solvent. Although the complexes were previously reported, in the present paper it is disclosed an alternative method for the synthesis of the complex 2, as well as additional characterization data on these complexes including EPR and cyclic voltammetry. The complexes were able to oxidize cyclohexane into cyclohexanol, cyclohexanone, cyclohexyl hydroperoxide and adipic acid, in mild conditions. Complex 2 exhibited the best results, reaching as high as 68.9% of total yield in 24 h with H2O2. In general, H2O2 showed better results than tert-butyl hydroperoxide as terminal oxidant. (c) 2006 Elsevier B.V. All rights reserved.