Improved methodology for non-covalent immobilization of tert-butyl-azabis(oxazoline)-copper complex on Al-MCM41

Copper sites are supported on Al-MCM41 by thermally treating copper(II) triflate that was deposited using the incipient wetness method. The change of the chemical state of the triflate anions following thermal treatment is monitored using TGA and SEM-EDX. Thermal treatment yields copper sites that t...

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Detalles Bibliográficos
Autores: Feldman, Robert A., Fraile, José M.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/154696
Acceso en línea:http://hdl.handle.net/10261/154696
Access Level:acceso abierto
Palabra clave:Asymmetric catalysis
Mesoporous materials
Copper
Bis(oxazolines)
Immobilized catalysts
Descripción
Sumario:Copper sites are supported on Al-MCM41 by thermally treating copper(II) triflate that was deposited using the incipient wetness method. The change of the chemical state of the triflate anions following thermal treatment is monitored using TGA and SEM-EDX. Thermal treatment yields copper sites that then can be modified with chiral tert-butyl-azabis(oxazoline) by adding a solution of this ligand to the support using incipient wetness. The catalyst produced in this way is efficient and stable with good enantioselectivity, and can be used in the cyclopropanation of styrene with ethyl diazoacetate under conditions employing an elevated temperature. The use of thermal treatment in the catalyst preparation method produces catalysts that are superior to the solids prepared by cation exchange or incipient wetness of the pre-formed complex.