Catalytic hydrodechlorination of benzyl chloride promoted by Rh–N-heterocyclic carbene catalysts

The rhodium(I) complexes [Rh(Cl)(COD)(R-NHC-(CH2)3Si(OiPr)3)] [COD=cyclooctadiene; R=2,6-diisopropylphenyl (1 a); n-butyl (1 b)] are effective catalyst precursors for the homogeneous hydrodechlorination of benzyl chloride using HSiEt3 as hydrogen source. This reaction is selective to the formation o...

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Detalles Bibliográficos
Autores: Lázaro, Guillermo, Polo, Víctor, Fernández-Álvarez, Francisco J., García-Orduña, Pilar, Lahoz, Fernando J., Iglesias, Manuel, Pérez-Torrente, Jesús J., Oro, Luis A.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2014
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/108734
Acceso en línea:http://hdl.handle.net/10261/108734
Access Level:acceso abierto
Palabra clave:Heterogeneous catalysis
Homogeneous catalysis
Hydrodechlorinatio
Descripción
Sumario:The rhodium(I) complexes [Rh(Cl)(COD)(R-NHC-(CH2)3Si(OiPr)3)] [COD=cyclooctadiene; R=2,6-diisopropylphenyl (1 a); n-butyl (1 b)] are effective catalyst precursors for the homogeneous hydrodechlorination of benzyl chloride using HSiEt3 as hydrogen source. This reaction is selective to the formation of toluene. However, in presence of a stoichiometric amount of potassium tert-butoxide (KtBuO) the formation of mixtures containing toluene together with 17–19 mol % of the CC homocoupling product, namely PhCH2CH2Ph, is observed. A mechanism proposal based on experimental insights and theoretical calculations at the DFT level that allows explanation of the experimental findings is included. Moreover, the heterogeneous catalytic system based on catalyst 1 a supported on MCM-41 has been demonstrated to be effective for the solvent-free hydrodechlorination of benzyl chloride using HSiEt3 and HSiMe(OSiMe3)2.