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Resolución cinética mediante activación C-C catalizada por Rh de las ciclobutanonas a temperatura ambiente

Lin Deng¹, Yue Fu², Siu Yin Lee¹

¹Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States.

Journal of the American Chemical Society

|October 1, 2019

Resumen

Este estudio introduce una reacción altamente selectiva catalizada por Rh para resolver las ciclobutanonas, produciendo bloques de construcción quirales valiosos de manera eficiente a temperatura ambiente. El método alcanza una alta enantioselectividad, confirmada por cálculos de la teoría funcional de la densidad (DFT).

Área de la Ciencia:

Química orgánica
Catálisis
Síntesis asimétrica

Sus antecedentes:

Las ciclobutanonas son productos intermedios sintéticos versátiles.
El desarrollo de métodos eficientes para su funcionalización enantioselectiva sigue siendo un desafío.
La resolución cinética ofrece una vía a los compuestos quirales de las mezclas racémicas.

Objetivo del estudio:

Desarrollar una resolución cinética altamente selectiva de las ciclobutanonas.
Para sintetizar bicicletas quirales trans-5,6-fusionadas y ciclobutanonas sustituidas por C2.
Elucidar el mecanismo de la reacción catalítica utilizando métodos computacionales.

Principales métodos:

La reacción de "cortar y coser" catalizada por el rodio.
Resolución cinética de las ciclobutanonas.
Cálculos de la Teoría Funcional de la Densidad (DFT).
Uso del ligando DTBM-segfos.

Principales resultados:

Se obtiene un alto factor de selectividad (hasta 785) en la resolución cinética.
Se obtuvieron varias bicicletas fusionadas trans-5,6 y ciclobutanonas sustituidas por C2 con un excelente exceso enantiomérico (ee).
La reacción se lleva a cabo eficientemente a temperatura ambiente.
Los cálculos de DFT identificaron las interacciones estabilizadoras clave del ligando en el estado de transición.

Conclusiones:

La reacción catalizada por Rh desarrollada es una herramienta poderosa para la síntesis enantioselectiva de derivados de ciclobutanona.
El ligando DTBM-segfos juega un papel crítico en el logro de una alta enantioselectividad.
Los productos quirales sirven como bloques de construcción valiosos para otras aplicaciones sintéticas.

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