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Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
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Amina (((imine) difosfina catalizadores de hierro para la hidrogenación asimétrica de transferencia de cetonas e
Weiwei Zuo1, Alan J Lough, Young Feng Li
1Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
Science (New York, N.Y.)
|November 30, 2013
Resumen
Este estudio demuestra que los catalizadores a base de hierro con nuevos ligandos realizan eficientemente la hidrogenación asimétrica. Estos catalizadores abundantes en la Tierra ofrecen una alternativa sostenible a los metales preciosos para la producción de alcoholes y aminas enantiopuros.
Área de la Ciencia:
- La catálisis de la catálisis.
- Química organometálica Química orgánica de los metales.
- Química Sostenible y Sustentable.
Sus antecedentes:
- Los catalizadores de hidrogenación tradicionales se basan en metales preciosos raros y caros como el rutenio, el rodio y el paladio.
- Existe una necesidad crítica de catalizadores que utilicen elementos abundantes en la Tierra para la síntesis química sostenible.
Objetivo del estudio:
- Para validar una hipótesis mecanicista para la hidrogenación asimétrica catalizada por el hierro utilizando ligandos de aminadifosfina parcialmente saturados.
- Desarrollar una ruta sintética directa para los ligandos enantiopuros moldeados por hierro (II).
- Explorar la actividad catalítica y el mecanismo de estos nuevos catalizadores de hierro.
Principales métodos:
- Síntesis de los enantiopuros parcialmente saturados de aminas (P-NH-N-P) utilizando una plantilla de hierro (II).
- Hidrogenación asimétrica de cetonas e iminas utilizando isopropanol como donante de hidrógeno.
- Detección espectroscópica de hidruro de hierro y amida intermedios para dilucidar el mecanismo catalítico.
Principales resultados:
- Los complejos de hierro con ligandos P-NH-N-P catalizan efectivamente la reducción asimétrica de los enlaces polares en cetonas e iminas.
- Se lograron altas frecuencias de rotación (hasta 200 s−1) a temperatura ambiente (28°C).
- Se aclaró el mecanismo catalítico que involucra el hidruro de hierro y los intermediarios de amida.
Conclusiones:
- Los ligandos de aminas (aminas) difosfinas parcialmente saturadas activan el hierro para una hidrogenación asimétrica altamente eficiente.
- Este sistema catalítico basado en hierro proporciona una alternativa sostenible y rentable a los catalizadores de metales preciosos.
- El estudio presenta una estrategia sintética viable para los ligandos enantiopuros y conocimientos mecanicistas sobre el proceso catalítico.
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