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Explotación de grupos carbonilo para controlar el alqueno y el alquino catalizados por el rodio intermolecular
Thomas J Coxon1, Maitane Fernández1, James Barwick-Silk1
1Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, U.K.
Journal of the American Chemical Society
|July 18, 2017
Resumen
Las reacciones de hidroacilación catalizadas por el rodio convierten eficientemente los aldehídos sustituidos por β-carbonilo en valiosos compuestos 1,3-dicarbonilo. Este método ofrece altos rendimientos y selectividad para diversos alquenos y alquinas, incluido el control regioselectivo de los alquinas.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Metodología sintética
Sus antecedentes:
- La hidroacilación es una reacción clave para la formación de enlaces carbono-carbono.
- El desarrollo de sistemas catalíticos eficientes para la hidroacilación sigue siendo un área de investigación activa.
- Los aldehídos sustituidos por β-carbonilo son precursores sintéticos versátiles.
Objetivo del estudio:
- Explorar la utilidad de los aldehídos sustituidos por β-carbonilo en la hidroacilación catalizada por rodio.
- Desarrollar sistemas catalíticos eficientes y selectivos para esta transformación.
- Investigar el control de la regioselectividad en la hidroacilación de alquinos.
Principales métodos:
- Utilizando catalizadores catiónicos de rodio con ligandos de bisfosfina.
- Utilizando como sustratos las aldehidas β-amido, β-ester y β-ceto.
- Reaccionan aldehídos con una variedad de alquenos y alquinas.
- Investigación del efecto del ligando de Ampaphos en la regioselectividad de la hidroacilación de alquinas.
Principales resultados:
- Hidroacilación exitosa de aldehídos sustituidos por β-carbonilo con alquenos y alquinas.
- Altos rendimientos y excelente selectividad para los productos de 1,3-dicarbonilo.
- Amplio alcance del sustrato tanto para aldehídos como para socios insaturados.
- Demostración del interruptor de regioselectividad para la hidroacilación de alquinas utilizando el ligando de Ampaphos.
- Se proporcionan datos estructurales y conocimientos mecanicistas.
Conclusiones:
- Los aldehídos sustituidos por β-carbonilo son sustratos excepcionales para la hidroacilación catalizada por Rh.
- El sistema catalítico desarrollado proporciona un acceso eficiente a compuestos de 1,3-dicarbonilo sintéticamente útiles.
- La síntesis regioselectiva de isómeros lineales y ramificados a partir de alquinas es posible.
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