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Metátesis cruzada selectiva Z y homodimerización de 3E-1,3-Dienes: optimización de la reacción, análisis

Shao-Xiong Luo¹, Jeffrey S Cannon¹, Buck L H Taylor²

¹Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology , Pasadena, California 91125, United States.

Journal of the American Chemical Society

|October 1, 2016

Resumen

Los catalizadores de rutenio permiten la metástasis Z-selectiva de las olefinas de 3E-1,3-dienos para la homodimerización y la metástasis cruzada. Este método eficiente tolera grupos funcionales y sintetiza moléculas complejas, incluidas las feromonas de insectos.

Área de la Ciencia:

Química orgánica
Catálisis
Química sintética

Sus antecedentes:

La metátesis de olefinas es una poderosa reacción de enlace carbono-carbono.
El desarrollo de catalizadores selectivos para sustratos de dieno sigue siendo un desafío.
Los catalizadores Z-selectivos son cruciales para la síntesis de geometrías específicas de las olefinas.

Objetivo del estudio:

Para describir las reacciones de metástasis de olefinas Z-selectivas utilizando 3E-1,3-dienes.
Detallar un procedimiento para la homodimerización y la metátesis cruzada con alquenos terminales.
Para demostrar la utilidad de un nuevo catalizador de rutenio.

Principales métodos:

Se han utilizado catalizadores de rutenio benzilideno ciclometalizados selectivos con Z.
Los 3E-1,3-dienes empleados en las reacciones de homodimerización y metatesis cruzada.
La quimioselectividad del catalizador apalancado para los alquenos terminales sobre los E-alquenos internos.

Principales resultados:

Se obtienen altos rendimientos de productos de metátesis cruzada interna de E,Z-dieno.
Tolerancia demostrada de varios grupos funcionales.
Sólo se requiere un pequeño exceso (1,5 equiv) de la pareja de acoplamiento de dieno.
Los estudios computacionales apoyaron una vía de reacción dieno-primera.

Conclusiones:

El método desarrollado proporciona un acceso eficiente a los E,Z-dienes.
Esta reacción es valiosa para el rápido ensamblaje de objetivos moleculares complejos.
Con éxito sintetizó dos feromonas de insectos, mostrando la aplicación práctica del método.

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