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Reacciones oxidativas inducidas por difluoro-lambda3-bromano que forman enlaces carbono-carbono: etanol como socio

Masahito Ochiai¹, Akira Yoshimura, Takeshi Mori

¹Graduate School of Pharmaceutical Sciences, University of Tokushima, 1-78 Shomachi, Tokushima 770-8505, Japan. mochiai@ph.tokushima-u.ac.jp

Journal of the American Chemical Society

|February 29, 2008

Resumen

Este estudio introduce un nuevo método libre de metales para sintetizar enonas conjugadas a través del acoplamiento oxidativo de alquinos y alcoholes primarios. La reacción utiliza un reactivo específico de bromo hipervalente, ofreciendo una nueva vía en la síntesis orgánica.

Área de la Ciencia:

Química orgánica es la química orgánica.
Metodología sintética de la metodología sintética.
La catálisis de la catálisis.

Sus antecedentes:

Los reactivos hipervalentes de yodo y bromo son herramientas valiosas en la síntesis orgánica.
Las reacciones de acoplamiento oxidativo son cruciales para la formación de enlaces C-C.
Las enonas son versátiles bloques de construcción en la química orgánica.

Objetivo del estudio:

Desarrollar un método nuevo y libre de metales para sintetizar enonas conjugadas.
Para explorar la utilidad de los reactivos de bromo hipervalentes en reacciones de acoplamiento oxidativo.
Para investigar el mecanismo y el alcance de la reacción.

Principales métodos:

Acoplamiento oxidativo de alcinos terminales y alcoholes primarios.
Utilizando un reactivo difluoro-lambda3-bromano y un catalizador BF3-Et2O.
Condiciones de reacción sin metales.

Principales resultados:

Síntesis exitosa de enonas conjugadas en buenos rendimientos.
Se observó una alta estereoselectividad y regioselectividad.
Demostró la superioridad del lambda3-bromano sobre los reactivos de lambda3-yodo para esta transformación.

Conclusiones:

Se ha establecido un método nuevo, eficiente y selectivo para la síntesis de enonas conjugadas.
La reacción procede a través de un mecanismo propuesto que involucra la formación de aldehídos, la ciclización y la apertura del anillo.
Este trabajo amplía la utilidad sintética de los compuestos de bromo hipervalentes.

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