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Eficaz acoplamiento cruzado de alquil trifluoroboratos secundarios con cloruros de arilo - descubrimiento de la
Spencer D Dreher1, Peter G Dormer, Deidre L Sandrock
1Department of Process Research and the Catalytic Reactions Discovery and Development Laboratory, Merck and Co. Inc., 126 East Lincoln Avenue, Rahway, New Jersey 07065, USA. spencer_dreher@merck.com
Journal of the American Chemical Society
|June 28, 2008
Resumen
Los investigadores desarrollaron nuevos sistemas de catalizadores para acoplar organotrifluoroboratos con haluros de arilo desafiantes. Este estudio es el primero en explorar exhaustivamente el acoplamiento secundario de alquilborón con cloruros de arilo, revelando un mecanismo para sustratos obstaculizados.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis es la catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- Los organotrifluoroboratos son unos versátiles intermediarios sintéticos.
- Las reacciones de acoplamiento cruzado son cruciales para la formación de enlaces C-C.
- El acoplamiento de reactivos secundarios de alquilborón con haluros de arilo sigue siendo un desafío.
Objetivo del estudio:
- Descubrir nuevos sistemas de catalizadores para acoplar organotrifluoroboratos secundarios con cloruros de arilo y bromuros exigentes.
- Establecer el primer estudio exhaustivo sobre el acoplamiento cruzado de reactivos secundarios de alquilborón con cloruros de arilo.
- Para investigar el mecanismo de estas complejas reacciones de acoplamiento cruzado.
Principales métodos:
- Se empleó la experimentación en paralelo a microescala para examinar los sistemas de catalizadores.
- Variación sistemática de los ligandos y las condiciones de reacción.
- Análisis del producto para determinar el rendimiento, la selectividad e identificar isómeros.
Principales resultados:
- Se identificaron tres sistemas catalizadores efectivos para el acoplamiento cruzado deseado.
- El estudio acopló con éxito organotrifluoroboratos secundarios con cloruros de arilo y bromuros estérico y electrónicamente exigentes.
- Se propuso un mecanismo dependiente de ligandos que involucra la eliminación / reinserción de beta-hidruro para sustratos obstaculizados, lo que lleva a mezclas isoméricas.
Conclusiones:
- Se han desarrollado nuevos métodos catalíticos para el acoplamiento secundario de alquilborón con haluros de arilo.
- Los hallazgos proporcionan avances significativos en la química orgánica sintética, particularmente para la construcción de moléculas complejas.
- Comprender el mecanismo de reacción ofrece ideas para diseñar futuros sistemas catalíticos y mejorar la selectividad.
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