Study of the racemic and enantioselective hydrogenation of acetophenone and 3,4-dimethoxyacetophenone using platinum-based organotin catalysts

In this work, some results of the racemic and enantioselective hydrogenation of acetophenone and 3,4-dimethoxyacetophenone are presented. The employed catalysts were platinum-based modified with organotin precursors either chiral (Men3Sn-SnMen3) or achiral (SnBu4), and they were obtained via surface...

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Detalles Bibliográficos
Autores: Vetere, Virginia, Faraoni, María Belén, Santori, Gerardo Fabian, Podestá, Julio Cesar, Casella, Mónica Laura, Ferretti, Osmar Alberto
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2005
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/56075
Acceso en línea:http://hdl.handle.net/11336/56075
Access Level:acceso abierto
Palabra clave:3,4-Dimethoxyacetophenone
Acetophenone
Enantioselectivity
Hydrogenation
Men3sn-Snmen3
Organometallic Catalysts
https://purl.org/becyt/ford/2.4
https://purl.org/becyt/ford/2
Descripción
Sumario:In this work, some results of the racemic and enantioselective hydrogenation of acetophenone and 3,4-dimethoxyacetophenone are presented. The employed catalysts were platinum-based modified with organotin precursors either chiral (Men3Sn-SnMen3) or achiral (SnBu4), and they were obtained via surface organometallic chemistry on metals (SOMC/M) techniques. The presence of organotin fragments on the catalyst surface inhibits the aromatic ring hydrogenation, leading to the hydrogenation of both acetophenone and 3,4-dimethoxyacetophenone to the corresponding alcohol with selectivity higher than 99%. With both substrates, a rate acceleration when changing from the achiral catalyst PtSn-OM to the chiral one, PtSn-OM* was observed. The presence of menthyl groups may be responsible for the rate acceleration in the key step of enantiodifferentiation. In the 3,4-dimethoxyacetophenone hydrogenation, 39% enantiomeric excess was obtained, with a selectivity of nearly 100%.