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Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry

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La activación del enlace silicio-hidrógeno y la hidrosilación de alquenos mediados por complejos CpCo: un estudio

Vincent Gandon¹, Nicolas Agenet, K Peter C Vollhardt

¹UPMC Paris 06, Laboratoire de Chimie Organique (UMR CNRS 7611), Institut de Chimie Moléculaire (FR 2769), case 229, 4 place Jussieu, F-75252 Paris cedex 05, France. vincent.gandon@upmc.fr

Journal of the American Chemical Society

|February 13, 2009

Resumen

Los complejos triplet de ciclopentadienilcobalt activan enlaces silicio-hidrógeno para formar hidratos de sililcobalt. Los cálculos sugieren un mecanismo de dos estados y la viabilidad de la hidrosilación catalítica de alquenos utilizando estos complejos de cobalto.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
Química computacional es la química computacional.
La catálisis es la catálisis.

Sus antecedentes:

La activación del enlace silicio-hidrógeno (Si-H) es crucial para la química del silicio.
Los complejos de ciclopentadienilcobalto son catalizadores organometálicos muy versátiles.
La comprensión de los mecanismos de reacción es clave para el diseño de catalizadores.

Objetivo del estudio:

Para investigar el mecanismo de activación del enlace Si-H por el triplet ciclopentadienilcobalt.
Para explorar la estabilidad de configuración de los complejos de cobalto con ligandos sililo.
Evaluar la viabilidad de la hidrosilación catalítica utilizando estos sistemas.

Principales métodos:

Se emplearon cálculos de la Teoría Funcional de Densidad (DFT).
Se realizó un análisis de los estados electrónicos (singlet y triplet).
Se modelaron los estados de transición y las vías de reacción.

Principales resultados:

El triplet ciclopentadienilcobalt activa los enlaces Si-H para producir hidratos de sililcobalt individuales.
Los complejos de cobalto exhiben inestabilidad de configuración, sometidos a diastereoisomerización.
Es factible un mecanismo de dos estados para la transformación de hidruro de sililo a dihidruro de disililo.
Los intermediarios hidruro de puente facilitan la inversión del metal en el estado de singlet.

Conclusiones:

El estudio aclara una nueva vía para la activación de Si-H por complejos de cobalto.
Los cálculos predicen el potencial de hidrosilación catalítica de los alquenos.
Estos hallazgos ofrecen información sobre el diseño de nuevos catalizadores orgánicos de silicio.

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