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Una síntesis asimétrica catalítica a temperatura ambiente de los alenos con el ECNU-Phos

Yuli Wang¹, Wanli Zhang, Shengming Ma

¹Shanghai Key Laboratory of Green Chemistry and Chemical Process, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.

Journal of the American Chemical Society

|July 23, 2013

Resumen

Los investigadores desarrollaron un nuevo método catalítico para crear 2,3-alenoatos ópticamente activos a partir de carbonatos propargílicos racémicos. Este eficiente proceso a temperatura ambiente utiliza un catalizador de paladio y un nuevo ligando quiral de bisfosfina, ofreciendo acceso a ambos enantiómeros.

Área de la Ciencia:

Química orgánica es la química orgánica.
Catalización asimétrica por catálisis asimétrica.
Química organometálica Química orgánica de los metales.

Sus antecedentes:

El establecimiento de la quiralidad axial es crucial en la síntesis de moléculas orgánicas complejas.
Desarrollar métodos catalíticos eficientes para la síntesis asimétrica sigue siendo un desafío significativo.
Los carbonatos propargílicos son materiales de partida versátiles en la síntesis orgánica.

Objetivo del estudio:

Para informar de la primera carbonilación asimétrica catalítica de carbonatos propargílicos racémicos.
Desarrollar un método para acceder a 2,3-alenoatos ópticamente activos con alta enantioselectividad.
Introducir un nuevo ligando quiral de bisfosfina para reacciones catalizadas por el paladio.

Principales métodos:

Utilizando un catalizador de paladio, específicamente [(π-alilo) PdCl]2.
Empleando un nuevo ligando quiral de bisfosfina, (R) - o (S) -ECNU-Phos, basado en un esqueleto de bifenilo.
Realización de la reacción de carbonilación de carbonatos propargílicos racémicos a temperatura ambiente.

Principales resultados:

Logró la primera carbonilación asimétrica catalítica de carbonatos propargílicos racémicos.
Síntesis de 2,3-alenoatos ópticamente activos con un exceso enantiomérico bastante alto (ee).
Se demostró que ambos enantiómeros de los alenoatos se pueden obtener mediante el uso de (R) - o (S) -ECNU-Phos.

Conclusiones:

El método desarrollado proporciona una ruta eficiente a los 2,3-alenoatos enriquecidos enantioméricamente.
El nuevo ligando quiral de la bisfosfina, ECNU-Phos, es eficaz para promover una alta enantioselectividad en reacciones catalizadas por el paladio.
Este trabajo amplía el conjunto de herramientas para la síntesis asimétrica, particularmente para acceder a los alenoatos quirales.

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