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Cicloadición enantioselectiva azida-internal-alquina catalizada por Rh para la construcción de 1,2,3-triazoles

Wen-Ting Guo¹, Bo-Han Zhu¹, Yi Chen¹

¹College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou 325035, China.

Journal of the American Chemical Society

|April 8, 2022

Resumen

Este estudio introduce un nuevo método para crear 1,2,3-triazoles axialmente quirales utilizando cicloadición asimétrica azida-alquina catalizada por rodio con alquinas internas. Este avance permite una síntesis eficiente de moléculas quirales complejas a las que antes era difícil acceder.

Área de la Ciencia:

Química orgánica
Catálisis asimétrica
Química medicinal

Sus antecedentes:

La cicloadición asimétrica azida-alquina catalizada por metales de transición (AAC) ha avanzado en la síntesis quiral de 1,2,3-triazol.
Los métodos existentes utilizan principalmente alquinas terminales, lo que limita las aplicaciones para la quiralidad central.
La cicloadición enantioselectiva con alquinas internas y la síntesis de triazoles de biarilo axialmente quirales siguen siendo poco exploradas.

Objetivo del estudio:

Desarrollar una síntesis atroposelectiva y atómico-económica de 1,4,5-triazoles quirales axialmente sustituidos.
Para utilizar las alcinas y azidas internas en la cicloadición Rh catalizada por Rh (E-RhAAC).
Construir atropisómeros de cinco miembros (hetero) como unidades quirales del núcleo.

Principales métodos:

Cicloadición azida-alquina catalizada por Rh enantioselectiva (E-RhAAC) de alquinos y azidos internos.
Utilizando condiciones de reacción suaves con una excelente tolerancia del grupo funcional.
Utilizando cálculos de la teoría funcional de densidad (DFT) para dilucidar los orígenes de la selectividad.

Principales resultados:

Síntesis exitosa de 1,2,3-triazoles quirales axialmente sustituidos con rendimientos de moderados a excelentes (hasta el 99%).
Se obtienen enantioselectividades de altas a excelentes (hasta el 99% ee) con un control regional específico.
Se ha demostrado una amplia aplicabilidad en la forja de varios triazoles axialmente quirales C-C.

Conclusiones:

El E-RhAAC desarrollado proporciona una ruta fácil y eficiente para desafiar a los triazoles axialmente quirales.
El método ofrece una herramienta valiosa para construir moléculas quirales complejas y atropisómeros.
Los cálculos DFT ofrecen información sobre los mecanismos de reacción, guiando futuras estrategias de síntesis asimétricas.

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