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Arilación catalítica selectiva B-H de los aldehídos de o-carboranilo mediante una estrategia de dirección transitoria
Xiaolei Zhang1, Hongning Zheng1, Jie Li1
1School of Pharmaceutical Sciences, School of Biotechnology, Jiangnan University , Wuxi, Jiangsu 214122, P. R. China.
Journal of the American Chemical Society
|August 8, 2017
Resumen
La arilación directa de los aldehídos de o-carboranilo se logró mediante catálisis con paladio y un grupo de dirección derivado de la glicina. Este método permite la funcionalización selectiva de los enlaces B-H de la jaula de carborano, dando como resultado productos diarilados o monoarilados.
Área de la Ciencia:
- Química organometálica
- Química del boro
- Síntesis orgánica
Sus antecedentes:
- Los aldehídos de carboranilo son sintones valiosos para la derivación del carborano.
- Su utilidad sintética está limitada por la débil coordinación del grupo aldehído en comparación con los ácidos carboxílicos.
- La funcionalización directa de los enlaces B-H de la jaula de carborano sigue siendo un desafío sintético.
Objetivo del estudio:
- Desarrollar un nuevo método para la arilación directa de los aldehídos de o-carboranilo.
- Para lograr la funcionalización selectiva de los enlaces B-H de la jaula de carborano.
- Para ampliar las aplicaciones sintéticas de los aldehídos de carboranilo.
Principales métodos:
- Arilación directa de aldehídos de o-carboranilo catalizada por el paladio.
- Generación in situ de un grupo de dirección utilizando glicina.
- Funcionalización del enlace B-H de la jaula en las posiciones B (4,5) o B (4).
Principales resultados:
- Síntesis exitosa de los aldehídos de o-carboranilo diarilados y monoarilados con un rendimiento de bueno a excelente.
- Se obtiene una alta selectividad en el proceso de arilación.
- Tolerancia de una amplia gama de grupos funcionales.
- El grupo aldehído puede ser eliminado o convertido en metanol después de la arilación.
Conclusiones:
- Se ha establecido un nuevo método catalizado por Pd para la arilación directa de aldehídos de o-carboranilo.
- El uso de un grupo de dirección derivado de la glicina facilita la funcionalización selectiva de B-H.
- Este enfoque mejora la versatilidad sintética de los aldehídos de carboranilo en la química del organoboron.
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