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El enlace H como elemento de control en la metátesis estereoselectiva de olefinas catalizadas por Ru
Amir H Hoveyda1, Pamela J Lombardi, Robert V O'Brien
1Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA. amir.hoveyda@bc.edu
Journal of the American Chemical Society
|May 30, 2009
Resumen
La unión de hidrógeno intramolecular mejora significativamente las reacciones de metátesis de olefinas catalizadas por rutenio. Este enfoque permite reacciones altamente estereoselectivas de apertura de anillo / metástasis cruzada con tasas y rendimientos mejorados.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Síntesis estereoselectiva de síntesis.
Sus antecedentes:
- El enlace de hidrógeno es ampliamente utilizado en el diseño de catalizadores para la síntesis estereoselectiva.
- Su aplicación en procesos catalizados por metales, particularmente en la metátesis de las olefinas, sigue siendo poco explorada.
Objetivo del estudio:
- Para investigar el impacto de la unión de hidrógeno intramolecular en la metátesis de olefinas catalizadas por rutenio.
- Desarrollar reacciones de apertura de anillo/metatesis cruzada (DROCM) eficientes y estereoselectivas.
Principales métodos:
- Utilizó catalizadores de rutenio achirales con alcoholes alelicos enriquecidos enantioméricamente.
- Interacciones de enlace de hidrógeno intramolecular explotadas para controlar la estereoquímica.
- Desarrolló reacciones diastereoselectivas de apertura de anillo / metástasis cruzada.
Principales resultados:
- Se lograron reacciones DROCM excepcionalmente fáciles y altamente diastereoselectivas.
- Las reacciones procedieron rápidamente (< 2 mol % catalizador, minutos) con alta conversión (> 98%) y rendimiento (hasta 87%).
- Los productos exhibieron una alta pureza estereoquímica (hasta > 98:2 dr y 11:1 E:Z).
Conclusiones:
- El enlace de hidrógeno intramolecular es una poderosa estrategia para mejorar la velocidad y el estereocontrol en la metátesis de olefinas catalizadas por Ru.
- Este método proporciona acceso a productos sintéticamente valiosos con un excelente control estereoquímico.
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