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Síntesis enantioconvergente mediada por conteriones de anillos medios axialmente quirales
Ji-Yuan Du1,2, Tudor Balan1, Tim D W Claridge1
1Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom.
Journal of the American Chemical Society
|August 3, 2022
Resumen
Este estudio introduce una nueva reacción enantioconvergente para sintetizar lactamas de anillo medio quirales a partir de anílidos de biarilo racémicos. El proceso utiliza un catalizador quiral para lograr una alta estereoselectividad, ofreciendo una nueva ruta sintética para compuestos valiosos.
Área de la Ciencia:
- Química orgánica
- Síntesis asimétrica
- Catálisis
Sus antecedentes:
- Las reacciones enantioconvergentes son escasas, especialmente para sustratos racémicos complejos.
- La síntesis de lactamas de anillo medio quirales con alto estereocontrol sigue siendo un desafío.
- Los métodos catalíticos enantioselectivos existentes para estos compuestos son limitados.
Objetivo del estudio:
- Desarrollar una síntesis altamente enantio y diastereoselectiva de lactamos de anillo medio.
- Para explorar una reacción de C-alquilación intramolecular dirigida por contra-iones.
- Proporcionar un nuevo enfoque catalítico para acceder a los valiosos lactamos quirales.
Principales métodos:
- Tratamiento de anílidos de biarilo racémicos con una sal de amonio derivada de la quinidina en condiciones básicas.
- Utilizando una reacción de C-alquilación dirigida por contraiones intramoleculares.
- Empleando un proceso de relajación de configuración impulsado por el enolado.
Principales resultados:
- Síntesis exitosa de lactamos de anillo medio con alta enantioselectividad y diastereoselectividad.
- Se han demostrado altas barreras a la inversión del cuenco (> 124 kJ mol-1) para los diastereoisómeros.
- Propuso un mecanismo que involucra la diferenciación quiral de sales de amonio de mezclas complejas de isómeros.
Conclusiones:
- Se ha desarrollado un proceso dinámico y enantioconvergente para sintetizar lactamas de anillo medio quirales.
- El método ofrece un enfoque operacionalmente simple para compuestos quirales valiosos.
- Este trabajo aborda la necesidad de métodos catalíticos enantioselectivos eficientes en esta área.
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