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Updated: Jul 12, 2025
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Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
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Hidroalquilación enantioselectiva de alqueno catalizada por iridio a través de una secuencia de
Changcheng Jing1, Wenbin Mao1, John F Bower1
1Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, United Kingdom.
Journal of the American Chemical Society
|October 25, 2023
Resumen
Este estudio introduce un nuevo método de acoplamiento descarboxilativo enantioselectivo. Utiliza un complejo de iridio quiral para la hidroalquilación eficiente de las olefinas, creando heteroarenos alquilados valiosos con alta selectividad.
Área de la Ciencia:
- Química organometálica
- Catálisis asimétrica
- Química orgánica sintética
Sus antecedentes:
- Las reacciones de hidroalquilación son cruciales para la formación de enlaces C-C.
- El logro de una alta enantioselectividad en la hidroalquilación ramificada sigue siendo un desafío.
- El acoplamiento cruzado descarboxilativo ofrece rutas sintéticas de economía atómica.
Objetivo del estudio:
- Desarrollar un nuevo método de hidroalquilación enantioselectiva para las olefinas.
- Utilización de los acetatos de terciobutilo de heteroarilo como socios de acoplamiento.
- Para sintetizar heteroarenos alquilados con estereocentros definidos.
Principales métodos:
- El uso de un complejo catiónico de Iridium (I) con ligando quiral de difosfina (DuanPhos).
- Estirenos y α-olefinas que reaccionan con el acetato de tert-butilo de heteroarilo.
- Descarboxilación in situ promovida por el ácido de los adutos iniciales.
Principales resultados:
- Se observó una selectividad ramificada completa en la hidroalquilación.
- Se ha logrado una enantioselectividad muy alta para los productos.
- Formación de heteroarenos alquilados con estereocentros β definidos.
- La reacción se produce a través de un intermediario quiral estereodeterminado de enolato de iridio.
Conclusiones:
- El método desarrollado representa un acoplamiento cruzado decarboxilativo enantioselectivo C ((sp3) -C ((sp3).
- Este método proporciona un acceso eficiente a los heteroarenos alquilados enriquecidos enantioméricamente.
- El mecanismo implica una enolización dirigida y una vía quiral de iridio-enolado.
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