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Una reacción de acoplamiento cruzado enantioselectivo C-H/C-H: método altamente eficiente para preparar ferroceno

De-Wei Gao¹, Qing Gu¹, Shu-Li You¹

¹State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Lu, Shanghai 200032, China.

Journal of the American Chemical Society

|February 20, 2016

Resumen

Este estudio introduce una nueva reacción catalizada por el paladio para acoplar ferrocenos y heteroarenos, logrando una alta selectividad a través de una vía de activación doble C-H utilizando aire como oxidante verde.

Área de la Ciencia:

Química organometálica
Catálisis
Síntesis asimétrica

Sus antecedentes:

Las reacciones de acoplamiento cruzado catalizadas por el paladio son vitales en la síntesis orgánica.
El desarrollo de métodos asimétricos para la activación de C-H sigue siendo un desafío importante.
Los compuestos de biarylo son motivos estructurales importantes en productos farmacéuticos y materiales.

Objetivo del estudio:

Desarrollar una nueva reacción asimétrica de acoplamiento cruzado oxidativa catalizada por Pd.
Para lograr el acoplamiento entre los ferrocenos y los heteroarenos a través de una vía de activación doble C-H.
Para utilizar un oxidante verde y evitar el exceso de reactivos.

Principales métodos:

Reacción catalizada por el paladio.
Acoplamiento cruzado oxidativo asimétrico.
Estrategia de activación del doble enlace C-H.
Utilizando el aire como oxidante.

Principales resultados:

Se obtienen eficiencias de reacción de moderadas a altas (36-86%).
Se ha demostrado un alto nivel de regioselectividad y enantioselectividad (95-99% ee).
La reacción procede a través de una doble vía de activación C-H.
No se requirió un exceso de socios de acoplamiento.
El aire sirvió como un oxidante eficaz y verde.

Conclusiones:

Este trabajo presenta el primer ejemplo de un acoplamiento biarílico asimétrico catalítico a través de la activación doble C-H.
Los productos quirales sintetizados son precursores versátiles para los ligandos y catalizadores quirales.
El método ofrece un enfoque eficiente y sostenible para los compuestos quirales valiosos.

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