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Difluoro-definición de gemas de compuestos diazo con TMSCF3 o TMSCF2Br: acoplamiento cruzado sin metales de

Mingyou Hu¹, Chuanfa Ni¹, Lingchun Li¹

¹Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Ling-Ling Road, Shanghai, 200032, China.

Journal of the American Chemical Society

|October 27, 2015

Resumen

Un nuevo método libre de metales de transición permite la síntesis de gem-difluoroalquenos mediante el acoplamiento de compuestos diazo con difluorocarbenos. Este eficiente protocolo amplía el acceso a valiosos compuestos difluorados para la síntesis orgánica.

Área de la Ciencia:

Química orgánica
Metodología sintética
Química del fluor

Sus antecedentes:

Los alquenos difluorados son bloques de construcción importantes en la química medicinal y la ciencia de los materiales.
Los métodos existentes para la difluoro-definación de gemas a menudo requieren metales de transición y tienen un alcance de sustrato limitado.

Objetivo del estudio:

Desarrollar un nuevo protocolo sin metales de transición para la síntesis de gem-difluoroalquenos.
Ampliar el alcance del sustrato y mejorar la eficiencia de las reacciones de difluorolefinación de gemas.

Principales métodos:

Desarrolló un nuevo protocolo de olefinación que implica el acoplamiento cruzado de fragmentos de carbenos no fluorados (de compuestos diazo) y fragmentos de difluorocarbenos (de reactivo Ruppert-Prakash o TMSCF2Br).
La reacción procede por adición nucleofílica de compuestos diazo a difluorocarbeno, seguido de la extrusión de nitrógeno.

Principales resultados:

Se ha conseguido una difluoro-definación general y eficiente libre de metales de transición.
Se han sintetizado con éxito varios 1,1-difluoroalquenos disubstituidos, incluidos los difluoroacrilatos, las diarildifluoroolefinas y las arylalquildifluoroolefinas.
Demostró un alcance de sustrato más amplio en comparación con los métodos catalizados con cobre anteriores.

Conclusiones:

El protocolo desarrollado sin metales de transición ofrece un enfoque versátil y eficiente para sintetizar diversos difluoroalquenos gemáticos.
La disponibilidad inmediata de los materiales de partida y la utilidad de los productos sugieren una amplia aplicabilidad en la síntesis orgánica.
Este método supera las limitaciones de los enfoques catalíticos anteriores, proporcionando una nueva herramienta valiosa para los químicos.

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