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Los ligandos sulfonamido-fosforamidita en la catálisis de hidrogenación dinuclear cooperativa
Frederic W Patureau1, Sandra de Boer, Mark Kuil
1Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands.
Journal of the American Chemical Society
|April 29, 2009
Resumen
Los nuevos catalizadores dinucleares Rh-Rh, formados utilizando ligandos sulfonamido-fosforamidita, hidrogenan de manera eficiente los acetamidoalquenos cíclicos obstaculizados. Estos catalizadores utilizan un nuevo mecanismo dinuclear cooperativo para una alta selectividad.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La catálisis es la catálisis.
- Química computacional es la química computacional.
Sus antecedentes:
- Se sabe que los ligandos sulfonamido-fosforamidita coordinan los metales.
- Los complejos metálicos dinucleares pueden exhibir propiedades catalíticas únicas.
- Las reacciones de hidrogenación son fundamentales en la síntesis orgánica.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevos complejos dinucleares Rh-Rh.
- Investigar la actividad catalítica y la selectividad de estos complejos en reacciones de hidrogenación.
- Para dilucidar el mecanismo de la activación del hidrógeno y la catálisis utilizando métodos computacionales.
Principales métodos:
- Síntesis de complejos dinucleares Rh-Rh que incluyen ligandos sulfonamido-fosforamidita.
- Hidrogenación de acetamidoalquenos cíclicos obstaculizados.
- Cálculos de la teoría funcional de la densidad (DFT) para estudiar los mecanismos de reacción.
Principales resultados:
- Formación de complejos dinucleares Rh-Rh "en forma de barco" a través del puente aniónico P-N.
- Activación del hidrógeno molecular (H2) a través de un mecanismo endocíclico dinuclear cooperativo.
- Alta actividad catalítica y una selectividad sin igual en la hidrogenación de acetamidoalquenos cíclicos obstaculizados.
- Identificación de un nuevo mecanismo cooperativo de activación de la hidrogenación.
Conclusiones:
- Los ligandos sulfonamido-fosforamidita permiten la formación de catalizadores dinucleares Rh-Rh activos.
- Se ha descubierto un nuevo mecanismo dinuclear cooperativo para la activación y hidrogenación de H2.
- Estos catalizadores ofrecen un rendimiento superior para desafíos específicos de hidrogenación.
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