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Un intermediario putativo de rutenio-dihidrógeno en la hidrogenación de cetonas
Robin J Hamilton1, Carolyn G Leong, Glen Bigam
1Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
Journal of the American Chemical Society
|March 24, 2005
Resumen
Se sintetizaron y estudiaron los complejos de dihidrógeno de rutenio, específicamente el trans-[Ru((R) -BINAP) ((H) ((Eta2-H2) ((R,R) -dpen) ]+ . El intermedio requiere una fuente de base o hidruro para la actividad catalítica, no muestra protonación de disolvente significativa.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Investigación de la investigación de la catálisis.
- Coordinación Química de la Coordinación
Sus antecedentes:
- Los complejos de rutenio con ligandos quirales de fosfina como (R) -BINAP son cruciales en la catálisis asimétrica.
- Comprender el comportamiento de los ligandos de dihidrógeno en los intermediarios de rutenio catiónico es clave para el diseño de catalizadores.
Objetivo del estudio:
- Para sintetizar y caracterizar un supuesto intermediario de dihidrógeno catiónico de un complejo de rutenio.
- Para investigar la estabilidad y la reactividad de este intermediario de dihidrógeno con respecto al disolvente y la actividad catalítica.
Principales métodos:
- Reacción de fac-[Ru((R) -BINAP) ((H) ((2-PrOH) 3) + con (R,R) -dpen bajo H2 a baja temperatura.
- 1H espectroscopia de RMN para estudiar el ligando dihidrógeno y sus interacciones.
- Análisis del intercambio de H-D entre el disolvente intermedio y el desterrado.
Principales resultados:
- El dihidrógeno catiónico intermedio trans-[Ru((R) -BINAP) ((H) ((eta2-H2) ((R,R) -dpen) ]+ se generó sin intercambio H-D.
- El ligando dihidrógeno no protonó significativamente el disolvente 2-PrOH.
- El intermedio por sí solo no es catalíticamente activo.
Conclusiones:
- El intermediario de dihidrógeno sintetizado es estable bajo las condiciones estudiadas.
- La actividad catalítica de este complejo de rutenio requiere la adición de una fuente de hidrógeno o base.
- Este hallazgo proporciona información sobre el mecanismo de activación de los catalizadores de hidrogenación de rutenio.
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