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Reacciones directas catalíticas asimétricas de Mannich para la construcción de estereocentros de carbono cuaternario

Barry M Trost¹, Tanguy Saget¹, Chao-I Joey Hung¹

¹Department of Chemistry, Stanford University , Stanford, California 94305-5080, United States.

Journal of the American Chemical Society

|March 9, 2016

Resumen

Este estudio introduce un nuevo método catalítico para crear moléculas complejas. El catalizador de zinc-profenol permite una síntesis eficiente de estereocentros de carbono cuaternario utilizando cetonas ramificadas alfa.

Área de la Ciencia:

Química orgánica
Catálisis
Síntesis estereoselectiva

Sus antecedentes:

Los estereocentros cuaternarios de carbono prevalecen en los productos farmacéuticos y naturales.
Los métodos eficientes para su síntesis estereoselectiva siguen siendo un desafío en la química orgánica.

Objetivo del estudio:

Desarrollar una nueva reacción catalítica de Mannich para la construcción directa de estereocentros cuaternarios de carbono enantio y diastereoselectivos.
Para utilizar cetonas ramificadas alfa como socios nucleófilos en esta transformación.

Principales métodos:

Empleando un catalizador de Zn-Profenol para la reacción de Mannich.
Utilizando cetonas ramificadas alfa como nucleófilos.
Investigación de las condiciones de reacción a escala de gramos con baja carga de catalizador.

Principales resultados:

Se ha conseguido una construcción enantio- y diastereoselectiva directa de estereocentros cuaternarios de carbono.
Eficiencia de reacción demostrada en escala de gramos con baja carga del catalizador (por ejemplo, 1 mol%).
Demostró la capacidad de elaborar aún más los adductos de Mannich con un control completo de diastereo.

Conclusiones:

La reacción de Mannich catalizada por Zn-ProPhenol proporciona una ruta efectiva para las estereotriadas complejas.
Este método ofrece un enfoque escalable y eficiente para sintetizar bloques de construcción quirales valiosos.

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