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Las reacciones catalíticas, asimétricas y "interrumpidas" Feist-Bénary son reacciones catalíticas, asimétricas y

Michael A Calter¹, Ryan M Phillips, Christine Flaschenriem

¹Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459-0180, USA. mcalter@wesleyan.edu

Journal of the American Chemical Society

|October 20, 2005

Resumen

Los derivados de pirimidina quiral de los alcaloides de cinchona catalizan la reacción interrumpida Feist-Bénary, produciendo hidroxidihidrofuranos sustituidos. Esta síntesis asimétrica logra una alta enantioselectividad y diastereoselectividad bajo condiciones suaves.

Área de la Ciencia:

Química orgánica es la química orgánica.
Catalización asimétrica por catálisis asimétrica.
Metodología sintética de la metodología sintética.

Sus antecedentes:

La reacción Feist-Bénary es un método clásico para sintetizar derivados de furano.
El desarrollo de métodos catalíticos asimétricos eficientes para la síntesis de moléculas complejas es un desafío significativo en la química orgánica.
Los alcaloides de Cinchona son privilegiados andamios quirales ampliamente utilizados en la catálisis asimétrica.

Objetivo del estudio:

Desarrollar nuevos catalizadores asimétricos para la reacción interrumpida Feist-Bénary.
Para sintetizar hidroxidihidrofuranos altamente sustituidos con alto estereocontrol.
Para investigar el mecanismo catalítico de la reacción asimétrica.

Principales métodos:

Síntesis de derivados de pirimidina de los alcaloides de la cinchona.
Aplicación de estos derivados como catalizadores en la reacción interrumpida Feist-Bénary.
Análisis estereoquímico de los productos de reacción utilizando cromatografía quiral y espectroscopia de RMN.
Estudios mecánicos que incluyen experimentos cinéticos y modelado computacional.

Principales resultados:

Se descubrió que los derivados de pirimidina de los alcaloides de cinchona eran excelentes catalizadores asimétricos.
La Reacción Feist-Bénary Interrumpida procedió en condiciones suaves, proporcionando hidroxidihidrofuranos altamente sustituidos.
Se observaron altas enantioselectividades con las bromoketonas no sustituidas.
Se lograron excelentes enantio- y diastereoselectividades con sustratos sustituidos.
Los estudios mecánicos indicaron que la sal de hidrobromuro del derivado alcaloide es la especie catalítica activa.

Conclusiones:

Los alcaloides de cinchona funcionalizados con pirimidina quiral son catalizadores muy efectivos para las reacciones asimétricas de Feist-Bénary interrumpidas.
Esta metodología proporciona una ruta fácil a los hidroxidihidrofuranos enriquecidos enantioméricamente.
El sistema catalítico ofrece un amplio alcance de sustrato y una alta estereoselectividad, lo que lo hace valioso para la síntesis orgánica.

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