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Síntesis y actividad de los complejos de alquilideno de rutenio coordinados con la fosfina y los ligandos de carbenos
Tina M Trnka1, John P Morgan, Melanie S Sanford
1Arnold and Mabel Beckman Laboratory of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Journal of the American Chemical Society
|February 27, 2003
Resumen
Este estudio introduce un nuevo método de síntesis más seguro para los catalizadores de rutenio utilizando ligandos protegidos de carbenos N-heterocíclicos (NHC), mejorando su utilidad en las reacciones de metátesis de olefinas.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis por catálisis.
Sus antecedentes:
- Los complejos de rutenio con fosfina y los ligandos de carbenos N-heterocíclicos (NHC) son cruciales en la metátesis de las olefinas.
- La síntesis tradicional de estos catalizadores implica el manejo de NHCs libres potencialmente inestables.
Objetivo del estudio:
- Desarrollar una ruta sintética mejorada para complejos de rutenio-NHC.
- Explorar el uso de aductos NHC protegidos para facilitar el manejo.
- Para evaluar la actividad catalítica de los complejos sintetizados en la metátesis de olefinas.
Principales métodos:
- Síntesis de complejos de alquilideno de rutenio utilizando aductos de NHC-alcohol o -cloroformo.
- Preparación de complejos estéricamente voluminosos bis ((NHC).
- Caracterización de complejos, incluida la determinación de la estructura cristalina.
- Evaluación del rendimiento catalítico en la metástasis de cierre de anillo (RCM) y la polimerización de la metástasis de apertura de anillo (ROMP).
Principales resultados:
- Se estableció una nueva y ventajosa ruta sintética utilizando ligandos NHC protegidos.
- Se sintetizaron con éxito complejos de rutenio estérilmente voluminosos bis (NHC).
- Se determinaron las estructuras cristalinas de un derivado mixto bis ((NHC) y un producto de activación C-H.
- Los complejos de rutenio coordinados por NHC sintetizados demostraron actividad de metátesis de olefinas.
Conclusiones:
- Los aductos protegidos de NHC ofrecen una alternativa más segura y conveniente a los NHC libres para la síntesis de catalizadores de rutenio.
- Los métodos desarrollados permiten la preparación de diversos y activos catalizadores de metátesis de olefinas de rutenio-NHC.
- Se justifica una mayor investigación sobre las reacciones secundarias y el rendimiento del catalizador.
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