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Bromolactonización enantioselectiva de las eninas (Z) conjugadas

Wei Zhang¹, Suqing Zheng, Na Liu

¹School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705, USA.

Journal of the American Chemical Society

|March 3, 2010

Resumen

Este estudio introduce un nuevo método catalítico para la bromolactonización enantioselectiva de las eninas. El proceso crea eficientemente bromoalenas y lactonas quirales con alta estereoselectividad.

Área de la Ciencia:

Química orgánica es la química orgánica.
La catálisis es la catálisis.
Metodología sintética de la metodología sintética.

Sus antecedentes:

La síntesis enantioselectiva es crucial para los productos farmacéuticos.
El desarrollo de nuevos métodos catalíticos para la síntesis de moléculas complejas está en curso.
La bromolactonización ofrece una ruta a los heterociclos funcionalizados.

Objetivo del estudio:

Para desarrollar una enantioselectiva catalítica sin-1,4-bromolactonización de las (Z) -eninas. conjugadas.
Para sintetizar de manera eficiente los bromoalenos di-, tri- y tetrasubstituidos y los heterociclos de lactona.
Para investigar el mecanismo del catalizador quiral.

Principales métodos:

Reacción catalítica de sin-1,4-bromolactonización enantioselectiva y catalizadora.
Uso de las eninas (Z) conjugadas como sustratos.
Empleando un catalizador quiral y N-bromosuccinimida (NBS).

Principales resultados:

Se obtienen altas proporciones diastereoméricas (>20:1).
Se obtiene hasta un 99% de exceso enantiomérico.
Síntesis eficiente y estereoselectiva de bromoalenos y lactonas sustituidas.

Conclusiones:

Se ha establecido una nueva bromolactonización catalítica enantioselectiva de (Z) eninas.
El método proporciona acceso a valiosos bromoalenos y lactonas quirales.
El catalizador quiral probablemente actúa como un reactivo bifuncional.

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