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Escisión de enlaces carbono-oxígeno con complejos sándwich de eta9,eta5-bis(indenilo) zirconio
Christopher A Bradley1, Luis F Veiros, Doris Pun
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14853, USA.
Journal of the American Chemical Society
|December 21, 2006
Resumen
Los complejos de bis ((indenilo) zirconio cortan fácilmente los enlaces C-O en éteres dialquilo, formando complejos de hidróxido de alkoxi. Este mecanismo de reacción implica la activación de C-H que determina la velocidad y la posterior eliminación de beta-alcóxido.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Química del zirconio Química del zirconio
- La catálisis de la catálisis.
Sus antecedentes:
- Los complejos de bis ((indenilo) zirconio son compuestos organometálicos versátiles.
- Comprender su reactividad con éteres es crucial para las aplicaciones sintéticas.
Objetivo del estudio:
- Investigar el mecanismo de reacción de los complejos de bis ((indenil) zirconio con éteres dialquilo.
- Para dilucidar la formación de complejos de alcóxi-hidruro y olefinas libres.
Principales métodos:
- Tratamiento del complejo de eta9,eta5-bis(indenilo) zirconio con varios éteres dialquilo.
- Estudios del efecto del isótopo cinético y análisis de la tasa.
- La termólisis de los compuestos de THF de eta6,eta5-bis(indenilo) zirconio.
- Estudios mecánicos y computacionales.
Principales resultados:
- Se produjo una fácil escisión de enlaces C-O, dando como resultado complejos de alcóxido hidruro de zirconio eta5,eta5-bis ((indenilo) y olefinas.
- Se aisló un raro complejo de etileno eta5,eta5-bis, libre de bases, caracterizado cristalográficamente, cuando se formó el etileno.
- La evidencia apoya un mecanismo que involucra la activación de C-H que determina la velocidad seguida de la eliminación de beta-alcóxido.
- La termólisis de los compuestos THF de eta6,eta5-bis(indenilo) zirconio también condujo a la escisión del enlace C-O.
Conclusiones:
- La reacción se lleva a cabo a través de un mecanismo que incluye la reorganización haptotrópica, la activación de C-H y la escisión del enlace C-O.
- Este estudio proporciona información sobre la reactividad de los complejos de bis ((indenilo) zirconio con éteres, relevantes para la síntesis organometálica y la catálisis.
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