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Difuncionalización asimétrica catalizada por iridio de los enlaces C-C σ habilitados por complejos de boronato de
Hong-Cheng Shen1, Mihai V Popescu2, Ze-Shu Wang1
1School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K.
Journal of the American Chemical Society
|July 20, 2023
Resumen
Este estudio introduce un método catalizado por iridio para la difuncionalización asimétrica de enlaces C-C utilizando complejos de boronato de biciclo [1.1.0] butilo (BCB). La nueva reacción produce ciclobutanos enriquecidos con enantio con una diastereoselectividad única contra la adición.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Metodología sintética
Sus antecedentes:
- Los compuestos de organoboron son intermediarios cruciales en la síntesis orgánica y el descubrimiento de fármacos.
- Las reorganizaciones enantioselectivas de 1,2-metalato de los alquenilboronatos ofrecen una ruta a valiosos reactivos quirales.
- La difuncionalización asimétrica de los enlaces C-C sigue siendo un desafío significativo en la química sintética.
Objetivo del estudio:
- Desarrollar un nuevo alilado asimétrico catalizado por iridio inducido por el reordenamiento de 1,2-metalato de complejos de boronato de biciclo [1.1.0] butilo (BCB).
- Para lograr la difuncionalización asimétrica de los enlaces C-C sigma, incluida la descarbonización y la carbonización.
- Para sintetizar productos tridimensionales de ciclobutanos 1,1,3-trisubstituidos enriquecidos con enantio.
Principales métodos:
- Reorganización inducida por alilación asimétrica catalizada por iridio de 1,2-metalato.
- Utilizando la liberación de tensión en los complejos de biciclo[1.1.0]butil (BCB) boronato.
- Empleando datos experimentales y cálculos de la teoría funcional de la densidad (DFT) para conocimientos mecanicistas.
Principales resultados:
- Difuncionalización asimétrica exitosa de los enlaces C-C sigma.
- Acceso a una variedad de productos de ciclo butano 1,1,3-trisubstituidos enriquecidos con enantio que contienen un éster de boro.
- Observación de diastereoisómeros *trans* exclusivos resultantes de la *anti*-adición, en contraste con las vías de *sin*-adición anteriores.
Conclusiones:
- El protocolo desarrollado proporciona un método novedoso y eficiente para sintetizar estructuras quirales complejas de ciclobutano.
- La diastereoselectividad *anti*-adición observada se atribuye a la alta nucleofilicidad de los complejos de boronato BCB y los estados de transición temprana.
- Este trabajo amplía el alcance de la difuncionalización asimétrica y ofrece bloques de construcción valiosos para futuras aplicaciones sintéticas.
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