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Control regiocímico en la transposición catalizada por metales de éteres silílicos alílicos
1Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
Journal of the American Chemical Society
|June 22, 2006
Resumen
Un nuevo método controla la regioquímica en la transposición del grupo sililoxi alilico utilizando heptoxido de renio (Re2O7). Esta estrategia utiliza boronatos de vinilo para el atrapamiento eficiente y la transferencia de alta quiralidad en los reordenamientos.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis por catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- Las reacciones de transposición de [1,3]-alilo son fundamentales en la síntesis orgánica.
- El control de la regioquímica y la quiralidad en estas transformaciones sigue siendo un desafío clave.
Objetivo del estudio:
- Desarrollar un nuevo sistema catalítico para la regioselectiva alilica [1,3]-transposición de los grupos sililoxi.
- Investigar la utilidad de los intermedios generados en reacciones de acoplamiento cruzado posteriores.
- Para evaluar el grado de transferencia de quiralidad durante el reordenamiento.
Principales métodos:
- La catálisis mediante el uso de heptoxido de renio (Re2O7).
- Generación de boronatos de vinilo cis-orientados a través de la reacción de Alder-ene entre éteres de sililo homoalílicos y boronatos de alquinyl.
- Reacciones de acoplamiento cruzado utilizando los intermediarios del ácido borónico cíclico.
Principales resultados:
- Se logró un nuevo control regioquímico sobre la [1,3]-transposición alílica de los grupos sililoxi.
- La estrategia atrapa efectivamente al grupo hidroxilo alílico utilizando boronatos de vinilo generados in situ.
- Los ácidos borónicos cíclicos resultantes son adecuados para reacciones de acoplamiento cruzado.
- Se observó una transferencia de quiralidad alta de éteres silílicos alílicos enriquecidos con enantio.
Conclusiones:
- El método desarrollado catalizado por Re2O7 ofrece una nueva vía para la transposición alilica regioselectiva.
- Este enfoque proporciona acceso a valiosos intermediarios de ácido borónico cíclico para su posterior elaboración sintética.
- El método demuestra un excelente control sobre la estereoquímica, lo que permite una alta transferencia de quiralidad.
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