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Reacción de alquilación alilica catalizada por iridio con ligandos de N-arilfosforamidita: estudios de alcance y

Wen-Bo Liu¹, Chao Zheng, Chun-Xiang Zhuo

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

Journal of the American Chemical Society

|February 8, 2012

Resumen

Los nuevos ligandos de N-arilo fosforamidita permiten una alquilación alílica altamente selectiva catalizada por iridio. Los estudios mecánicos revelan las formas activas del iridaciclo a través de la activación del enlace C (((sp (((2)) -H, avanzando la química catalítica.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
La catálisis de la catálisis.
Química orgánica sintética y orgánica.

Sus antecedentes:

La alquilación alilica es una reacción crucial para la formación de enlaces carbono-carbono.
La catálisis del iridio ofrece una reactividad y selectividad únicas en la síntesis orgánica.
El desarrollo de ligandos eficientes es clave para optimizar las reacciones catalizadas por metales de transición.

Objetivo del estudio:

Para sintetizar y evaluar nuevos ligandos de N-arilo fosforamidita para la alquilación alilica catalizada por iridio.
Para lograr una alta regionalidad y enantioselectividad en estas transformaciones.
Para dilucidar el mecanismo de reacción, incluida la formación de las especies catalíticas activas.

Principales métodos:

Síntesis de una serie de ligandos de N-arilo fosforamidita.
Aplicación de estos ligandos en reacciones de alquilación alilica catalizadas por iridio.
Investigaciones mecanicistas utilizando cálculos de la Teoría Funcional de la Densidad (DFT) y cristalografía de rayos X.

Principales resultados:

Los ligandos desarrollados proporcionan altas regioselectividades y enantioselectividades en un amplio alcance de sustrato.
Los carbonatos de cinamil orto-sustituidos demuestran conveniencia sintética y buena tolerancia al grupo funcional.
Los estudios mecánicos confirmaron la formación del intermediario activo del iridaciclo a través de la activación del enlace C(sp(2)) -H.

Conclusiones:

Los ligandos de N-aryl phosphoramidite son efectivos para la alquilación alilica altamente selectiva catalizada por iridio.
La vía de activación C(sp(2)) -H es crucial para generar las especies catalíticas activas.
Este trabajo proporciona información valiosa sobre el diseño de los ligandos y la comprensión mecánica de la catálisis del iridio.

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