How to optimize a C-H cleavage with a mononuclear copper-dioxygen adduct?

摘要

We here report the investigations on the role of the charge transfer (CT) from copper toward dioxygen on the activation barrier of the C-H bond breaking in a model [Cu(trenCH(3))(O-2)](+) adduct. By playing on the donating capability of the trenCH(3) ligand, by means of a supplementary pseudopotential applied on the apical nitrogen atom, the existence of an optimum CT to achieve the rupture of the C-H bond is revealed. When considering the dioxygen/superoxide/peroxide range in its whole, it appears that both dioxygen- and peroxide-type complexes are poor oxidant toward the C-H bond. At variance, superoxide dominant complexes are confirmed to be better suited for a reactive purpose. (c) 2008 Wiley Periodicals, Inc.