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Moléculas inspiradas en flavaglinas ópticamente activas por una alquilación alilica descarboxilada catalizada por el

Meng-Yue Cao^1,2,3, Bin-Jie Ma^1,2, Zhi-Qi Lao^1,2

¹Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China.

Journal of the American Chemical Society

|June 26, 2020

Resumen

Una nueva reacción catalizada por el paladio permite la alquilación alilica asimétrica de los benzofuranos. Este método facilita la síntesis de estructuras complejas de flavaglina, ofreciendo potencial para el desarrollo de nuevos fármacos.

Área de la Ciencia:

Química orgánica
Catálisis
Química medicinal

Sus antecedentes:

Las reacciones catalizadas por el paladio son cruciales en la síntesis orgánica moderna.
La alquilación alilica asimétrica (AAA) es una herramienta poderosa para crear moléculas quirales.
Las flavaglinas son una clase de productos naturales con aplicaciones terapéuticas potenciales.

Objetivo del estudio:

Desarrollar una eficiente descarboxilación dearomativa asimétrica (AAA) de los benzofuranos.
Establecer una síntesis orientada a la diversidad (DOS) para la construcción de andamios complejos.
Para explorar nuevas rutas sintéticas para el descubrimiento de fármacos basados en flavaglina.

Principales métodos:

Utilizó ligandos de bisfosfina de tipo Trost recientemente descubiertos con un marco quiral de cicloalcanos.
Se utiliza un catalizador de paladio ((2) (dba) 3) para la reacción AAA.
Desarrolló una secuencia de múltiples pasos que incluye AAA, oxidación de Wacker-Grubbs-Stoltz, condensación intramolecular de benzoína y adición conjugada.

Principales resultados:

Se obtiene una alta eficiencia (carga de catalizador de 0,2-1,0% mol) y enantioselectividad (90-96% ee) en el AAA de los benzofuranos.
Demostró una buena generalidad con más de 30 ejemplos, dando un producto del 82-99%.
Sintetizó con éxito flavaglines previamente inaccesibles con un andamio compacto de ciclopenta [b] benzofuran y estereocentros contiguos.

Conclusiones:

Los ligandos de tipo Trost desarrollados permiten una AAA catalizada por el paladio altamente enantioselectiva de los benzofuranos.
La nueva estrategia DOS proporciona un acceso eficiente a las estructuras complejas de la flavaglina.
Este enfoque abre nuevas vías para el descubrimiento y desarrollo de terapias basadas en flavaglina.

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