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Escenario mecanicista completo para los estereocentros de carbono terciario de forja por sulfonilación propargílica

Aleria Garcia-Roca^1,2, Raúl Pérez-Soto^1,2, Georgiana Stoica¹

¹Institute of Chemical Research of Catalonia (ICIQ), the Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007 Tarragona, Spain.

Journal of the American Chemical Society

|March 8, 2023

Resumen

Este estudio revela el paso clave de enantio-discriminación en las reacciones quirales de sustitución propargílica catalizadas por cobre. El paso de proto-desmetalización, no el acoplamiento inicial, dicta el resultado estereocímico, ofreciendo nuevas ideas sobre la síntesis asimétrica.

Área de la Ciencia:

Química orgánica
Catálisis asimétrica
Mecanismo de reacción

Sus antecedentes:

Las transformaciones propargílicas catalizadas por metales son vitales para la formación de enlaces C-C y C-heteroátomo.
La comprensión mecánica de la sustitución propargílica asimétrica, especialmente para los estereocentros complejos, sigue siendo limitada.

Objetivo del estudio:

Para llevar a cabo un análisis mecanicista detallado de una sulfonilación propargílica catalizada por cobre quiral.
Elucidar el paso enantio-discriminativo en la formación de estereocentros terciarios sustituidos por heteroátomos.

Principales métodos:

Utilizó una combinación de técnicas experimentales.
Estudios computacionales empleados para la investigación mecanicista.
Validación de los resultados mediante el cálculo de los niveles de enantio-inducción en diversas condiciones.

Principales resultados:

Identificó el paso de proto-demetalización como el evento enantio-discriminatorio crucial.
Reveló un escenario mecanicista completo, incluida la preactivación del catalizador y el ciclo catalítico.
Se observó un efecto no lineal inesperado en el nivel de oxidación de Cu.

Conclusiones:

El paso de proto-demetalización es crítico para el control estereocímico en esta reacción.
Proporciona un marco mecanicista completo para la sustitución quiral propargílica.
Destaca la importancia de considerar todas las etapas de los ciclos catalíticos asimétricos.

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