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La alilación regioselectiva y enantioselectiva catalizada por iridio de trimetilsiloxifuranos
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|September 8, 2012
Resumen
Desarrollamos un nuevo método para la alilación regio y enantioselectiva del trimetilsiloxifurano utilizando un catalizador de iridio. Esta reacción crea valiosos butenolidos 3-sustituidos con una alta pureza enantiomérica.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- Los enolados de éster son versátiles intermediarios sintéticos.
- El acceso a los butenolidos 3-sustituidos enantioenriquecidos es sintéticamente importante.
- El desarrollo de métodos catalíticos para la funcionalización selectiva es un objetivo clave en la síntesis orgánica.
Objetivo del estudio:
- Para reportar una nueva alilación regio y enantioselectiva de trimethylsiloxyfuran.
- Desarrollar un sistema catalítico para la síntesis de 3-butenolides sustituidos.
- Para investigar el mecanismo de la reacción de alilación.
Principales métodos:
- El uso de un catalizador de iridio metalacíclico.
- Reacción del trimetilsiloxifurano con carbonatos alilicos o benzoatos.
- Análisis de los productos de reacción para la regioselectividad y la enantioselectividad.
Principales resultados:
- La reacción se produjo selectivamente en la posición 3 de trimethylsiloxyfuran.
- Los productos de sustitución ramificada se formaron con un alto enriquecimiento enantiomérico.
- Se utilizó con éxito una variedad de carbonatos alelicos aromáticos y benzoatos alelicos alifáticos.
- Los estudios estequiométricos indicaron la activación del trimetilsiloxifurán por el grupo que deja el carboxilato.
Conclusiones:
- La reacción catalizada por iridio desarrollada proporciona un acceso eficiente a los butenolides enantioenriquecidos 3-sustituidos.
- La metodología ofrece una herramienta valiosa para la síntesis de moléculas orgánicas complejas.
- El grupo que deja el carboxilato juega un papel crucial en la activación del sustrato de furano.
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