title: Mechanistic insights into C-H amination via dicopper nitrenes.
abstract: We examine important reactivity pathways relevant to stoichiometric and catalytic C-H amination via isolable β-diketiminato dicopper alkylnitrene intermediates {[Cl2NN]Cu}2(μ-NR). Kinetic studies involving the stoichiometric amination of ethylbenzene by {[Cl2NN]Cu}2(μ-N(t)Bu) (3) demonstrate that the terminal nitrene [Cl2NN]Cu═N(t)Bu is the active intermediate in C-H amination. Initial rates exhibit saturation behavior at high ethylbenzene loadings and an inverse dependence on the copper species [Cl2NN]Cu, both consistent with dissociation of a [Cl2NN]Cu fragment from 3 prior to C-H amination. C-H amination experiments employing 1,4-dimethylcyclohexane and benzylic radical clock substrate support a stepwise H-atom abstraction/radical rebound pathway. Dicopper nitrenes [Cu]2(μ-NCHRR') derived from 1° and 2° alkylazides are unstable toward tautomerization to copper(I) imine complexes [Cu](HN═CRR'), rendering 1° and 2° alkylnitrene complexes unsuitable for C-H amination.
authors: Department of Chemistry, Georgetown University, Box 571227-1227, Washington, DC 20057, United States.
authors: Mae Joanne B
authors: MJ
authors: Aguila
authors: Yosra M
authors: YM
authors: Badiei
authors: Timothy H
authors: TH
authors: Warren
mesh_terms: D000586:Amination; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007097:Imines / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D007097:Imines; D009942:Organometallic Compounds; C017621:phenylnitrene; D003300:Copper