Mechanistic insights into C-H amination via dicopper nitrenes.
J Am Chem Soc
; 135(25): 9399-406, 2013 Jun 26.
Article
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| MEDLINE
| ID: mdl-23656170
ABSTRACT
We examine important reactivity pathways relevant to stoichiometric and catalytic C-H amination via isolable ß-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]CuâN(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](HNâCRR'), rendering 1° and 2° alkylnitrene complexes unsuitable for C-H amination.
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Bases de datos:
MEDLINE
Asunto principal:
Compuestos Organometálicos
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Cobre
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Idioma:
En
Revista:
J Am Chem Soc
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos