Rhodium-NHC Hybrid Silica Materials as Recyclable Catalysts for [2+2+2] Cycloaddition Reactions of Alkynes

Bis-silylated dihydroimidazolium salt 1 and monosilylated imidazolium salt 2 are transformed to (NHC)RhCl(COD) complexes 3 and 4, allowing the preparation of hybrid silica materials either by sol-gel or grafting processes. Full characterization of the materials by means of solid state NMR, N-2-sorpt...

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Detalles Bibliográficos
Autores: Fernández Wang, Martí, Ferré Romeu, Meritxell, Pla i Quintana, Anna, Parella Coll, Teodor, Pleixats, Roser, Roglans i Ribas, Anna
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2014
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/11333
Acceso en línea:http://hdl.handle.net/10256/11333
Access Level:acceso abierto
Palabra clave:Catàlisi heterogènia
Heterogeneous catalysis
Catalitzadors de rodi
Rhodium catalyst
Reaccions d'addició
Addition reactions
Rodi
Rhodium
Ciclització (Química)
Ring formation (Chemistry)
Descripción
Sumario:Bis-silylated dihydroimidazolium salt 1 and monosilylated imidazolium salt 2 are transformed to (NHC)RhCl(COD) complexes 3 and 4, allowing the preparation of hybrid silica materials either by sol-gel or grafting processes. Full characterization of the materials by means of solid state NMR, N-2-sorption measurements, thermogravimetric analysis (TGA) and elemental analysis was followed by evaluation of catalytic activity in the [2+2+2] cycloaddition of alkynes. Excellent yields of the cycloadducts are obtained for up to six consecutive cycles with the grafted material, using simple filtration to recover the catalyst. Both conventional and microwave heating prove effective for the process described