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Phosphinylation alilico regiocatalizado por Rh y enantioselectivo

Bing Li¹, Min Liu¹, Sajid Ur Rehman¹

¹Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.

Journal of the American Chemical Society

|February 14, 2022

Resumen

Este estudio introduce un nuevo método catalizado por Rh para la creación de óxidos quirales de fosfina. Este avance permite la formación selectiva de enlaces carbono-fosforo, superando los desafíos anteriores de desactivación del catalizador.

Área de la Ciencia:

Química organometálica
Catálisis asimétrica
Síntesis orgánica

Sus antecedentes:

La sustitución alilica catalizada por metales de transición está bien establecida para varios nucleófilos.
La formación selectiva de enlaces carbono-fosforo a través de la sustitución alilica se ha visto obstaculizada por la desactivación del catalizador.
Los ligandos de fosfina a menudo desactivan los catalizadores debido a sus fuertes propiedades de coordinación.

Objetivo del estudio:

Desarrollar una síntesis altamente regioselectiva y enantioselectiva de óxidos de fosfina alílicos.
Para superar los problemas de desactivación del catalizador en la formación de enlaces carbono-fosforo.
Establecer un nuevo método para la fosforilación alilica asimétrica.

Principales métodos:

Se utilizó una reacción catalizada por Rh empleando un ligando quiral de bisoxasolina-fosfina.
Se emplean óxidos de α-hidroxialquilfosfina para mantener bajas concentraciones de óxidos secundarios de fosfina.
Se ha añadido ácido difetilfosfórico para activar los alcoholes alilicos y acelerar la formación de enlaces C-P.

Principales resultados:

Se ha logrado una síntesis altamente regioselectiva y enantioselectiva de óxidos de fosfina alílicos.
Se ha demostrado con éxito la formación de enlaces carbono-fosforo en la sustitución de alelo.
Se han identificado aditivos clave (óxidos de α-hidroxialquilfosfina y ácido difenilico fosfórico) cruciales para el alto rendimiento y la selectividad.

Conclusiones:

El sistema catalizado por Rh desarrollado proporciona una ruta efectiva para la fosforilación alilica asimétrica.
La estrategia de uso de óxidos de α-hidroxilafosfina es vital para la estabilidad del catalizador y la eficiencia de la reacción.
Este trabajo amplía el alcance de la sustitución alilica enantioselectiva para incluir la formación de enlaces carbono-fosforo.

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