Oxidation of Ni(II) to Ni(IV) with Aryl Electrophiles Enables Ni-Mediated Aryl–CF₃ Coupling

This communication describes the synthesis and reactivity of NiIV(aryl)­(CF3)2 complexes supported by tris­pyrazolyl­borate and 4,4′-di-tert-butyl­bipyridine ligands. We demonstrate that isolable NiIV complexes can be accessed under mild conditions via the oxidation of NiII precursors with S-(trifluoro­methyl)­dibenzo­thio­phenium triflate as well as with diaryliodonium and aryl diazonium reagents. The NiIV intermediates undergo high yielding aryl–CF3 bond-forming reductive elimination. These studies support the potential viability of NiIV intermediates in nickel-catalyzed coupling reactions involving diaryliodonium and aryldiazonium electrophiles.