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Diverso orto-C ((sp²) -H Funcionalización de los benzaldehídos utilizando grupos de dirección transitorios

Xi-Hai Liu¹, Hojoon Park², Jun-Hao Hu¹

¹School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology , Wuhan 430070, People's Republic of China.

Journal of the American Chemical Society

|December 23, 2016

Resumen

Este estudio introduce una nueva estrategia de grupo de dirección transitorio para funcionalizaciones orto-C ((sp2) -H versátiles de los benzaldehídos. Este método permite la arilación catalizada por el paladio, la cloración, la brominación y la amidación catalizada por el iridio sin grupos auxiliares.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

Las funcionalizaciones de C-H catalizadas por paladio que utilizan grupos de dirección transitorios se limitan principalmente a la arilación de C-H.
Los sustratos de benzaldehído poseen desafíos únicos de reactividad para la activación de C-H debido al potencial envenenamiento del catalizador y los grupos de dirección competidores.

Objetivo del estudio:

Desarrollar una estrategia versátil de funcionalización de ortho-C ((sp2) -H para los benzaldehídos.
Ampliar el alcance de la funcionalización C-H catalizada por metales más allá de la arilación utilizando grupos de dirección transitorios.
Para demostrar la aplicabilidad del método desarrollado en la síntesis de moléculas complejas.

Principales métodos:

Formación in situ de grupos direccionales transitorios a través de enlaces iminos en sustratos de benzaldehído.
La arilación C-H catalizada por el paladio (II), la cloración y la brominación.
Amidación C-H catalizada por el iridio.

Principales resultados:

Se han logrado diversas funcionalizaciones orto-C ((sp2) -H de los benzaldehídos, incluyendo la arilación, la cloración, la brominación y la amidación.
Demostró que los grupos de dirección transitorios anulan efectivamente a otros grupos funcionales de coordinación.
Se ha aplicado con éxito la metodología para la diversificación de un análogo de fármaco en etapa tardía.

Conclusiones:

La estrategia de grupo de dirección transitorio amplía significativamente el alcance de la funcionalización C-H catalizada por metales para los benzaldehídos.
Este enfoque ofrece una herramienta poderosa para sintetizar moléculas orgánicas complejas y funcionalizar análogos de fármacos.
El método desarrollado supera las limitaciones de las estrategias anteriores, permitiendo múltiples tipos de reacción con alta eficiencia.

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