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Acoplamiento reductor catalizado por níquel de bromuros de arilo con haluros de alquilo terciarios

Xuan Wang¹, Shulin Wang¹, Weichao Xue¹

¹School of Materials Science and Engineering and ‡Department of Chemistry, Shanghai University , 99 Shang-Da Road, Shanghai 200444, China.

Journal of the American Chemical Society

|September 2, 2015

Resumen

Una nueva reacción catalizada por níquel crea eficientemente centros cuaternarios complejos de todo carbono a partir de materiales iniciales simples. Este método ofrece una amplia tolerancia de grupo funcional, lo que lo hace valioso para sintetizar moléculas orgánicas intrincadas.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

Los haluros de alquilo terciarios son sustratos desafiantes en las reacciones de acoplamiento cruzado.
La formación de centros cuaternarios de todo el carbono es crucial para sintetizar moléculas orgánicas complejas.
Los métodos anteriores a menudo carecen de tolerancia de grupo funcional o requieren condiciones duras.

Objetivo del estudio:

Desarrollar un método suave y eficiente para la arilación reductiva de haluros de alquilo terciarios.
Para sintetizar moléculas que contienen todos los centros cuaternarios de carbono.
Investigar el alcance y las limitaciones del nuevo sistema catalítico.

Principales métodos:

Acoplamiento reductor catalizado por níquel de haluros de alquilo terciarios con bromuros de arilo.
Optimización de las condiciones de reacción, incluidos catalizadores, ligandos y aditivos.
Evaluación del alcance del sustrato y la tolerancia del grupo funcional.

Principales resultados:

Se estableció un protocolo de arilación reductora catalizada por níquel leve.
La reacción generó con éxito productos con centros cuaternarios de carbono en rendimientos de moderados a excelentes.
Se observó una excelente tolerancia del grupo funcional, y las arenas con déficit de electrones demostraron ser efectivas para prevenir la isomerización.

Conclusiones:

El método desarrollado catalizado por Ni proporciona una ruta fácil a los centros cuaternarios de todo el carbono.
La reacción exhibe una amplia aplicabilidad y una alta tolerancia de grupo funcional.
La piridina o la 4-dimetilamino) piridina facilitan la reacción, mientras que las sales de imidazolio pueden mejorar la eficiencia.

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