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La transferencia de átomos de oxígeno desde el dióxido de carbono a un carbeno de Fischer en (PNP) Ir
Matthew T Whited1, Robert H Grubbs
1Arnold and Mabel Beckman Laboratories of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|April 16, 2008
Resumen
Los complejos de iridio facilitan la activación de C-H y las reacciones de transferencia de átomos de oxígeno. Este estudio detalla la formación y la reactividad de un complejo de carbenos de iridio (I) Fischer, que permite una transferencia eficiente de átomos de CO2.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis de la catálisis.
- La activación de la C-H.
Sus antecedentes:
- Los ligandos de pinza son cruciales en la estabilización de complejos metálicos para aplicaciones catalíticas.
- Los complejos de carbenos de Fischer son intermediarios versátiles en la síntesis orgánica.
- La activación de C-H es una transformación clave para la funcionalización de las moléculas orgánicas.
Objetivo del estudio:
- Para investigar la formación y la reactividad de un complejo de carbenos de iridio (I) Fischer.
- Para explorar el potencial catalítico de este complejo en las reacciones de transferencia atómica.
- Para aclarar el mecanismo de estas transformaciones.
Principales métodos:
- Deshidrogenación de un complejo de dihidruro de iridio con norbornileno.
- Reacción del complejo de carbenos resultante con CO2, sulfuro de carbonilo y isocyanato de fenilo.
- Estudios de termólisis bajo atmósfera de CO2.
- Investigaciones mecanicistas preliminares. investigaciones mecánicas preliminares.
Principales resultados:
- Formación de un complejo de carbenos de iridio (I) Fischer, (PNP) Ir C (H) OtBu, a través de la activación doble C-H.
- Transferencia cuantitativa de átomos de oxígeno del CO2 para generar formato de t-butilo y (PNP) Ir-CO.
- Se observó la transferencia de átomos de azufre y grupos de nitreno con sulfuro de carbonilo y isocyanato de fenilo, respectivamente.
- Formación de (PNP) Ir-CO y formato de t-butilo a través de la termólisis bajo CO2.
Conclusiones:
- El complejo de iridio carbeno sintetizado es una plataforma eficaz para las reacciones de transferencia de átomos.
- Las reacciones proceden a través de un intermediario metallactona de cuatro miembros propuesto.
- Este trabajo amplía el alcance de los complejos de iridio ligados a pinzas en catálisis.
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