C鈥揌 Functionalization Reactivity of a Nickel鈥揑mide

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• 作者：Stefan Wiese ; Jason L. McAfee ; Dale R. Pahls ; Claire L. McMullin ; Thomas R. Cundari ; Timothy H. Warren
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：June 20, 2012
• 年：2012
• 卷：134
• 期：24
• 页码：10114-10121
• 全文大小：472K
• 年卷期：v.134,no.24(June 20, 2012)
• ISSN：1520-5126

文摘

We report bifunctional reactivity of the 尾-diketiminato Ni(III)鈥搃mide [Me₃NN]Ni鈺怤Ad (1), which undergoes H-atom abstraction (HAA) reactions with benzylic substrates R鈥揌 (indane, ethylbenzene, toluene). Nickel鈥搃mide 1 competes with the nickel鈥揳mide HAA product [Me₃NN]Ni鈥揘HAd (2) for the resulting hydrocarbyl radical R^{鈥?/sup> to give the nickel鈥揳mide [Me₃NN]Ni鈥揘(CHMePh)Ad (3) (R鈥揌 = ethylbenzene) or aminoalkyl tautomer [Me₃NN]Ni(畏2-CH(Ph)NHAd) (4) (R鈥揌 = toluene). A significant amount of functionalized amine R鈥揘HAd is observed in the reaction of 1 with indane along with the dinickel imide {[Me₃NN]Ni}₂(渭-NAd) (5). Kinetic and DFT analyses point to rate-limiting HAA from R鈥揌 by 1 to give R鈥?/sup>, 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鈥揌 amination systems that proceed via a HAA/radical rebound mechanism.}