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Sustitución alilica enantioselectiva catalizada por el cobre con los alquilboranos
Yoshinori Shido1, Mika Yoshida, Masahito Tanabe
1Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan.
Journal of the American Chemical Society
|October 31, 2012
Resumen
Este estudio introduce la primera sustitución alílica enantioselectiva y catalítica utilizando compuestos de alquilborón. El nuevo método crea eficientemente alquenos quirales con grupos alquilo funcionalizados, avanzando la síntesis asimétrica.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Síntesis asimétrica de síntesis.
- Química organometálica Química orgánica de los metales.
Sus antecedentes:
- Las reacciones de sustitución aliloides son fundamentales en la síntesis orgánica.
- El desarrollo de métodos enantioselectivos para la creación de centros quirales es crucial.
- Los compuestos de alquilborón ofrecen una reactividad única, pero han sido poco explorados en las sustituciones alilicas enantioselectivas.
Objetivo del estudio:
- Para lograr la primera reacción catalítica de sustitución alilica enantioselectiva empleando compuestos de alquilborón.
- Desarrollar un protocolo para la síntesis de alquenos terminales con un centro estereogénico ramificado con grupos sp{3) -alquilo.
- Establecer una estrategia eficiente para la síntesis enantioselectiva de alilisilanos quirales.
Principales métodos:
- Utilizados reactivos alquilo-9-BBN y cloruros alílicos primarios.
- Empleado un sistema catalítico de cobre ((I) -DTBM-SEGPHOS. empleado un sistema catalítico de cobre ((I) -DTBM-SEGPHOS.
- Reacciones investigadas con cloruros de alilo sustituidos por γ-silicio.
Principales resultados:
- Se obtienen excelentes selectividades γ y altas enantioselectividades en la sustitución alelica.
- Se han producido con éxito alquenos terminales que presentan un centro estereogénico alílico con grupos alquilo sp(3) funcionalizados.
- Demostró una estrategia eficiente para la síntesis enantioselectiva de α-estero-génico quiral allylsilanes.
Conclusiones:
- El sistema catalítico desarrollado representa un gran avance en la sustitución alilica enantioselectiva con reactivos de alquilborón.
- Este protocolo proporciona una ruta versátil a valiosos bloques de construcción quirales.
- Los hallazgos abren nuevas vías para la síntesis de moléculas orgánicas complejas con alto control estereoquímico.
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