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Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
Hidrogenólisis de palladio (II) complejos de hidróxido, fenoxido y alcóxido
Gregory R Fulmer1, Alexandra N Herndon, Werner Kaminsky
1Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Journal of the American Chemical Society
|September 22, 2011
Resumen
Este estudio sintetizó complejos de paladio para investigar la hidrogenólisis del enlace paladio-oxígeno. La selectividad para la hidrogenólisis se logró con ligandos de alcóxidos fluorados, aclarando las vías de reacción de los alcóxidos metálicos.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis por catálisis.
- Mecanismos de reacción Mecanismos de reacción
Sus antecedentes:
- Los enlaces paládio-oxígeno son intermediarios cruciales en varios procesos catalíticos.
- Comprender la reactividad de los alcóxidos y aryloxidos de paladio es clave para controlar los resultados catalíticos.
- La hidrogenólisis ofrece una ruta directa a las especies de hidruro de paladio, importantes en la catálisis.
Objetivo del estudio:
- Para sintetizar y caracterizar una serie de complejos de palladio ((II) -OR) de pinza.
- Para explorar la generalidad y la selectividad de las reacciones de hidrogenólisis para los enlaces paladio-oxígeno.
- Esclarecer los factores que influyen en la reactividad de los alcóxidos y aryloxidos de paladio.
Principales métodos:
- Síntesis de los complejos pincer ((tBu) PCP) Pd (II) -OR con diversos grupos R. Síntesis de los complejos pincer ((tBu) PCP) Pd (II) -OR con diversos grupos R. Síntesis de los complejos pincer ((tBu) PCP) Pd (II) -OR con diversos grupos R. Síntesis de los complejos pincer ((tBu) PCP) Pd (II) -OR con diversos grupos R. Síntesis de los complejos pincer ((tBu) PCP) Pd (II) -OR) con diversos grupos R. Síntesis de los complejos pincer ((tBu) PCP) Pd (II) -OR con diversos grupos R.
- Investigación de las reacciones de hidrogenólisis en condiciones variables.
- Análisis de las vías de reacción en competencia, incluida la hidrólisis y la abstracción de β-hidruro.
Principales resultados:
- La hidrogenólisis del hidróxido de paladio fue inhibida por la formación de dímeros.
- La reactividad del alcóxido de paladio y del aryloxide varió en función de las propiedades estéricas y electrónicas del ligando y la presencia de hidrógeno β.
- La hidrólisis y la abstracción de β-hidruro complicaron la hidrólisis de muchos sustratos.
- Se logró una alta selectividad para la hidrogenólisis con un ligando fluorado de 2-fluoroetoxido.
Conclusiones:
- La reactividad de los alcóxidos de metales de transición tardía es ajustable.
- El diseño de los ligandos es crítico para dirigir la reactividad de los enlaces paladio-oxígeno hacia vías deseadas como la hidrogenólisis.
- Los ligandos de alcóxido parcialmente fluorados son prometedores para las reacciones selectivas de hidrogenólisis.
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