title: C-H functionalization reactivity of a nickel-imide.
abstract: We report bifunctional reactivity of the β-diketiminato Ni(III)-imide [Me(3)NN]Ni═NAd (1), which undergoes H-atom abstraction (HAA) reactions with benzylic substrates R-H (indane, ethylbenzene, toluene). Nickel-imide 1 competes with the nickel-amide HAA product [Me(3)NN]Ni-NHAd (2) for the resulting hydrocarbyl radical R(•) to give the nickel-amide [Me(3)NN]Ni-N(CHMePh)Ad (3) (R-H = ethylbenzene) or aminoalkyl tautomer [Me(3)NN]Ni(η(2)-CH(Ph)NHAd) (4) (R-H = toluene). A significant amount of functionalized amine R-NHAd is observed in the reaction of 1 with indane along with the dinickel imide {[Me(3)NN]Ni}(2)(μ-NAd) (5). Kinetic and DFT analyses point to rate-limiting HAA from R-H by 1 to give R(•), which may add to either imide 1 or amide 2, each featuring significant N-based radical character. Thus, these studies illustrate a fundamental competition possible in C-H amination systems that proceed via a HAA/radical rebound mechanism.
authors.affiliation: Department of Chemistry, Georgetown University, Box 571227-1227, Washington, DC 20057, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wiese
authors.forename: Jason L
authors.initials: JL
authors.lastname: McAfee
authors.forename: Dale R
authors.initials: DR
authors.lastname: Pahls
authors.forename: Claire L
authors.initials: CL
authors.lastname: McMullin
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Cundari
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Warren