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Reacción directa asimétrica de tipo Mannich vinílica y bisvinílica catalizada por un complejo de cobre

Hai-Jun Zhang¹, Chang-Yun Shi¹, Feng Zhong¹

¹CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032, China.

Journal of the American Chemical Society

|February 1, 2017

Resumen

Una nueva reacción viníloga asimétrica catalítica de tipo Mannich logra una alta selectividad utilizando ligandos voluminosos de N-acilpirazol y bisfosfina. Este método se extiende a las reacciones bisvinílogas, mostrando una amplia utilidad sintética para la síntesis de moléculas complejas.

Área de la Ciencia:

Química orgánica
Catálisis asimétrica

Sus antecedentes:

La reacción de tipo Mannich es una reacción fundamental de formación de enlaces carbono-carbono.
El desarrollo de variantes asimétricas catalíticas es crucial para sintetizar moléculas quirales de manera eficiente.

Objetivo del estudio:

Para revelar una reacción catalítica asimétrica viníloga directa de tipo Mannich.
Establecer el control sobre la regio-, la diastereoselectividad y la enantioselectividad.
Explorar la extensión a las reacciones bisvinílogas y demostrar su utilidad sintética.

Principales métodos:

Se utilizó un sistema catalítico que combina un N-acilpirazol y un ligando de bisfosfina.
Se varió sistemáticamente el ligando para lograr reacciones de tipo Mannich bisvinílogas.
Realizó varias transformaciones en los productos vinílicos.

Principales resultados:

Se obtienen buenos rendimientos con una excelente regioselectividad, diastereoselectividad y enantioselectividad en la reacción viníloga de tipo Mannich.
Extendió con éxito el sistema catalítico a una reacción de tipo Mannich bisviníloga mediante la modificación del ligando.
Demostró la aplicabilidad sintética de los productos vinílicos resultantes a través de transformaciones químicas posteriores.

Conclusiones:

Se ha desarrollado una reacción viníloga asimétrica catalítica directa de tipo Mannich altamente selectiva.
El diseño del ligando es crítico para controlar la selectividad y permitir reacciones bisvinílogas.
La metodología proporciona bloques de construcción quirales valiosos para la síntesis orgánica.

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