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Método para la ligación altamente enantioselectiva de dos estereocentros quirales

Eswar Bhimireddy¹, E J Corey¹

¹Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States.

Journal of the American Chemical Society

|August 1, 2017

Resumen

Este estudio introduce un nuevo método para unir centros quirales en moléculas, preservando su configuración. El proceso acopla eficientemente dos estereocentros utilizando un nuevo intermediario de cobre, evitando la formación de radicales libres.

Área de la Ciencia:

Química orgánica
Estereoquímica
Química organometálica

Sus antecedentes:

Los estereocentros son cruciales para la función molecular.
Se necesitan métodos eficientes para acoplar los estereocentros con retención de la configuración.
Los métodos existentes a menudo carecen de eficiencia o estereoselectividad.

Objetivo del estudio:

Desarrollar un nuevo método para unir dos estereocentros de C ((sp3) litio-alfa.
Para lograr un acoplamiento eficiente con una completa conservación de la configuración.
Para explorar el mecanismo que implica un cobre (III) intermedio.

Principales métodos:

Utilizando un organocuprado quiral R2CuLi.
El uso de i-propil 2,4-dinitrobenzoato para una oxidación de dos electrones.
Formación de un complejo de cobre.
Realización de la eliminación reductiva acelerada a -90 °C.

Principales resultados:

La unión exitosa de dos estereocentros de C ((sp3) litio-alfa.
Se logró una completa conservación de la configuración.
La reacción procedió enantioselectivamente y exclusivamente.
No se observó formación de radicales libres.

Conclusiones:

El método descrito proporciona una ruta eficiente para la formación de enlaces estereoselectivos C(sp3) -C(sp3).
El cobre (III) intermedio juega un papel clave en la eliminación reductora enantioselectiva.
Este enfoque ofrece una herramienta valiosa para la síntesis asimétrica.

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