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Dihydrophenanthridine: un nuevo y fácilmente regenerable modelo de NAD(P) H para la hidrogenación asimétrica

Qing-An Chen¹, Kai Gao, Ying Duan

¹State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.

Journal of the American Chemical Society

|January 14, 2012

Resumen

Un nuevo modelo de nicotinamida adenina dinucleótido (fosfato) (NAD(P) H, 9,10-dihidrofenantridina (DHPD), permite una hidrogenación asimétrica eficiente de varios compuestos utilizando gas hidrógeno. Este enfoque biomimético logra una excelente enantioselectividad en una amplia gama de sustratos.

Área de la Ciencia:

Química orgánica es la química orgánica.
Catalización asimétrica por catálisis asimétrica.
Química biomimética es la química biomimética.

Sus antecedentes:

Las enzimas dependientes de nicotinamida adenina dinucleótido (fosfato) (NAD(P) H) son cruciales en las reducciones biológicas.
El desarrollo de modelos de NAD(P) H sintéticos eficientes y renovables es clave para la catálisis biomimética.
La hidrogenación asimétrica es una herramienta vital para la síntesis de moléculas quirales.

Objetivo del estudio:

Para diseñar y sintetizar un nuevo modelo de NAD(P) H fácilmente regenerable, 9,10-dihidrofenantridina (DHPD).
Para investigar la hidrogenación asimétrica biomimética de iminas y compuestos aromáticos utilizando DHPD y gas hidrógeno.
Para explorar el alcance del sustrato y la enantioselectividad de la reacción catalizada por DHPD.

Principales métodos:

Síntesis del modelo de la 9,10-dihidrofenantridina (DHPD) NAD(P) H. Síntesis del modelo de la 9,10-dihidrofenantridina (DHPD) NAD(P) H. Síntesis del modelo de la 9,10-dihidrofenantridina (DHPD) NAD
Reacciones asimétricas de hidrogenación utilizando DHPD como catalizador y gas hidrógeno como reductor.
Análisis de los productos de reacción para la actividad y la enantioselectividad utilizando varios sustratos, incluidas las benzoxazinonas, las benzoxazinas, las quinoxalinas y las quinolinas.

Principales resultados:

El modelo DHPD demostró un rendimiento eficiente y regenerable en hidrogenación asimétrica bajo condiciones suaves.
Se lograron excelentes actividades y enantioselectividades para un amplio alcance de sustrato, que se extiende más allá de las benzoxazinonas para incluir benzoxazinas, quinoxalinas y quinolinas.
Se observó una reversión inesperada de la enantioselectividad al comparar DHPD con otros modelos de NAD(P) H, atribuidos a diferentes vías de transferencia de hidruro.

Conclusiones:

El modelo DHPD desarrollado es un catalizador versátil y eficaz para la hidrogenación asimétrica biomimética.
El uso de gas hidrógeno como reductor terminal simplifica el sistema catalítico y mejora su aplicabilidad.
La inversión de enantioselectividad observada pone de relieve la importancia de la estructura del catalizador para dictar el resultado estereocímico de la reacción.

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