Hidrosilación catalítica de alquenos por un complejo de sileno de rutenio. Evidencia de un nuevo mecanismo de hidrosilación
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1Department of Chemistry and Center for New Directions in Organic Synthesis, University of California, Berkeley, Berkeley, California 94720-1460, USA.
Journal of the American Chemical Society
|November 6, 2003
Resumen
Se sintetizaron nuevos complejos de rutenio y osmio silileno con enlaces Si-H. Un catalizador de rutenio facilita la hidrociliación de alquenos, mostrando una alta selectividad para los silanos primarios y la adición de anti-Markovnikov a través de un nuevo mecanismo.
Área de la Ciencia:
- Química organometálica de las sustancias orgánicas.
- La catálisis por catálisis.
- Química del silicio y su química.
Sus antecedentes:
- Los complejos de sileno son reactivos intermedios en la química organometálica.
- La hidrosilación es una reacción clave para sintetizar compuestos orgánicos de silicio.
Objetivo del estudio:
- Para sintetizar nuevos complejos de rutenio y osmio silileno con enlaces Si-H.
- Para investigar la actividad catalítica de estos complejos en la hidrociliación de alquenos.
- Para dilucidar el mecanismo de la reacción de hidrosilación.
Principales métodos:
- Síntesis de complejos de rutenio y osmio silileno.
- Caracterización mediante la espectroscopia de resonancia magnética nuclear (RMN).
- Pruebas catalíticas para la hidrosilación de alceno.
Principales resultados:
- Síntesis y caracterización exitosas de nuevas especies de rutenio y osmio silileno que contienen enlaces Si-H.
- El complejo de rutenio [Cp*(iPr3P)(H) 2Ru=Si(H) Ph.Et2O][B(C6F5) [4] demostró una alta actividad catalítica en la hidrosilación de alquenos.
- Se observó una excelente selectividad de sustrato para los silanos primarios y una regioquímica exclusiva anti-Markovnikov.
- Se obtuvo evidencia de un nuevo mecanismo catalítico que implica la adición directa de un alqueno al enlace silileno Si-H.
Conclusiones:
- Se han preparado con éxito nuevos complejos de silileno de rutenio y osmio con enlaces Si-H.
- El catalizador de rutenio desarrollado es altamente eficaz para la hidrosilación de alquenos, ofreciendo un control preciso sobre la regioquímica y la selectividad del sustrato.
- Se ha propuesto una nueva vía mecanicista para la hidrosilación, lo que hace avanzar la comprensión de la química del sileno.
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