Cooperative catalysis involving copper(ii) complex bearing redox ligands allows generation of CF˙3 radicals through ligand-based SET while metallic oxidation state is preserved.

The reaction of a copper complex bearing iminosemiquinone ligands with a CF3(+) source provides an unprecedented Cu(II)-CF3 complex through ligand-based oxidation. Reactivity of this complex leads to nucleophilic trifluoromethylation of the ligand, suggesting an electronic interplay that results in a formal umpolung of the initial CF3(+).