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La catálisis de iridio en tándem como una estrategia general para la construcción atroposelectiva de estirenos

Jie Wang¹, Xiaotian Qi², Xiao-Long Min¹

¹School of Chemistry and Chemical Engineering, Nanjing University of Science & Technology, Nanjing 210094, China.

Journal of the American Chemical Society

|July 6, 2021

Resumen

Este estudio introduce una nueva reacción en tándem catalizada por iridio para sintetizar estirenos quirales axialmente. Este método eficiente utiliza la isomerización de sustitución alilica asimétrica, ofreciendo una nueva ruta a valiosos ligandos quirales.

Área de la Ciencia:

Química orgánica
Síntesis asimétrica
Catálisis

Sus antecedentes:

Los estirenos quirales axialmente son importantes como ligandos quirales potenciales en la síntesis asimétrica.
El desarrollo de métodos enantioselectivos para su preparación es un desafío importante.
Las metodologías sintéticas novedosas y eficientes son muy deseables.

Objetivo del estudio:

Informar sobre la primera estrategia de catálisis de iridio en tándem para la síntesis de estirenos quirales axialmente.
Desarrollar un método general que utilice la isomerización por sustitución alilica asimétrica (AASI).

Principales métodos:

Se empleó un enfoque de catálisis de iridio en tándem que incluye sustitución alilica asimétrica e isomerización in situ.
Utilizó análogos de carbonato de cinamilo como electrofilos y naftolos como nucleófilos.
Mecanismos de reacción investigados a través de estudios experimentales y computacionales, centrados en la activación y eliminación de enlaces C-H catalizados por iridio.

Principales resultados:

Sintetizó con éxito estirenos quirales axialmente a través de un proceso catalizado por iridio de dos ciclos.
Estereospecificidad demostrada en la etapa de isomerización, crucial para la transferencia de quiralidad, con el grupo hidroxilo del naftol desempeñando un papel clave.
Se obtienen excelentes rendimientos y altas enantioselectividades en una gama de sustratos con amplia compatibilidad de grupos funcionales.

Conclusiones:

La catálisis de iridio en tándem proporcionó una estrategia general y eficiente para acceder a estirenos quirales axialmente.
El enfoque AASI ofrece una vía novedosa para crear bloques de construcción quirales valiosos.
Los estirenos quirales axialmente sintetizados pueden transformarse aún más en diversas moléculas quirales.

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