title: Oxidation of Ni(II) to Ni(IV) with Aryl Electrophiles Enables Ni-Mediated Aryl-CF3 Coupling.
abstract: This communication describes the synthesis and reactivity of Ni(IV)(aryl)(CF3)2 complexes supported by trispyrazolylborate and 4,4'-di-tert-butylbipyridine ligands. We demonstrate that isolable Ni(IV) complexes can be accessed under mild conditions via the oxidation of Ni(II) precursors with S-(trifluoromethyl)dibenzothiophenium triflate as well as with diaryliodonium and aryl diazonium reagents. The Ni(IV) intermediates undergo high yielding aryl-CF3 bond-forming reductive elimination. These studies support the potential viability of Ni(IV) intermediates in nickel-catalyzed coupling reactions involving diaryliodonium and aryldiazonium electrophiles.
authors.affiliation: University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: James R
authors.initials: JR
authors.lastname: Bour
authors.affiliation: University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Camasso
authors.affiliation: University of Michigan, Department of Chemistry, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Melanie S
authors.initials: MS
authors.lastname: Sanford