C-H Activation of Benzene by a Photoactivated Ni(II)(azide): Formation of a Transient Nickel Nitrido Complex.
Photochemical activation of nickel-azido complex 2 [Ni(N3)(PNP)] (PN(H)P=2,2'-di(isopropylphosphino)-4,4'-ditolylamine) in neat benzene produces diamagnetic complex 3 [Ni(Ph)(PN(P)N(H))], which is crystallographically characterized. DFT calculations support photoinitiated N2-loss of the azido complex to generate a rare, transient Ni(IV) nitrido species, which bears significant nitridyl radical character. Subsequent trapping of this nitrido through insertion into the Ni-P bond generates a coordinatively unsaturated Ni(II) imidophosphorane P=N donor. This species shows unprecedented reactivity toward 1,2-addition of a C-H bond of benzene to form 3. The structurally characterized chlorido complex 4 [Ni(Cl)(PN(P)N(H))] is generated by reaction of 3 with HCl or by direct photolysis of 2 in chlorobenzene. This is the first report of aromatic C-H bond activation by a trapped transient nitrido species of a late transition metal.
Homogeneous, Bioinspired & Supramolecular Catalysis van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (The Netherlands).
Vincent
V
Vreeken
Department of Chemistry, John Hopkins University, 3400 N Charles Street, Baltimore, MD 21218 (USA).
Maxime A
MA
Siegler
Homogeneous, Bioinspired & Supramolecular Catalysis van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (The Netherlands).
Bas
B
de Bruin
Homogeneous, Bioinspired & Supramolecular Catalysis van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (The Netherlands).
Joost N H
JN
Reek
Department of Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht (The Netherlands).
Martin
M
Lutz
Homogeneous, Bioinspired & Supramolecular Catalysis van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (The Netherlands). j.i.vandervlugt@uva.nl.
Jarl Ivar
JI
van der Vlugt
D001386:Azides / Q000737:chemistry*; D001554:Benzene / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006859:Hydrogen / Q000737:chemistry; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009532:Nickel / Q000737:chemistry*; D011789:Quantum Theory; D013816:Thermodynamics
D001386:Azides; D056831:Coordination Complexes; D002244:Carbon; D009532:Nickel; D006859:Hydrogen; D001554:Benzene
CH activation; azides; iminophosphoranes; nickel; nitridyl radical