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catalizadores inmovilizados de bisdiazaphospholane para la hidroformilación asimétrica
Tyler T Adint1, Clark R Landis
1Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison Wisconsin 53706, United States.
Journal of the American Chemical Society
|April 19, 2014
Resumen
Los catalizadores de hidroformilación asimétrica inmovilizados derivados de bis-3,4-diazafosfolanos (BDP) muestran una alta selectividad y actividad comparable a los catalizadores homogéneos. Estos catalizadores reciclables ofrecen un excelente rendimiento con una lixiviación mínima de rodio tanto en sistemas de lote como de flujo.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis es la catálisis.
- Química verde es la química verde.
Sus antecedentes:
- Los catalizadores homogéneos ofrecen una alta selectividad, pero plantean desafíos de separación.
- La inmovilización de los catalizadores es crucial para la reciclabilidad y la sostenibilidad.
- Los bis-3,4-diazafosfolanos (BDP) son ligandos efectivos en la catálisis asimétrica.
Objetivo del estudio:
- Desarrollar y evaluar catalizadores inmovilizados de hidroformilación asimétrica (iAHF).
- Para comparar el rendimiento de los catalizadores BDP inmovilizados con sus homólogos homogéneos.
- Para evaluar la reciclabilidad y la lixiviación de catalizadores de hidroformilación inmovilizados.
Principales métodos:
- Adhesión covalente de enantiopuros bis-3,4-diazafosfolanos (BDPs) a soportes de cuentas y sílice a través de la funcionalización del ácido carboxílico.
- Formación de catalizadores de hidroformilación inmovilizados mediante la exposición de BDPs atados a Rh (acac) (CO) 2.
- Evaluación del rendimiento del catalizador en la hidroformilación asimétrica de alquenos procirales en condiciones de lote y flujo.
Principales resultados:
- Los catalizadores inmovilizados en resinas de Tentagel demostraron una alta regioselectividad y enantioselectividad, comparables a los catalizadores homogéneos.
- La actividad del catalizador, corregida por la carga, se acercó a la de los análogos homogéneos.
- Se observó una excelente reciclabilidad y una lixiviación mínima de rodio tanto en reactores de lote como de flujo.
- Los catalizadores ligados a la sílice exhibieron una reducida enantioselectividad.
Conclusiones:
- Los catalizadores inmovilizados basados en BDP son efectivos para la hidroformilación asimétrica, ofreciendo alta selectividad y actividad.
- Los catalizadores con soporte de tentáculo proporcionan una alternativa reciclable y sostenible a los sistemas homogéneos con una lixiviación mínima de metales.
- Se necesita una optimización adicional para los catalizadores soportados por sílice para mejorar la enantioselectividad.
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