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La carbocianatión catalizada por níquel de los alquinos con cianuros de alilo
Yasuhiro Hirata1, Tomoya Yukawa, Natsuko Kashihara
1Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
Journal of the American Chemical Society
|September 3, 2009
Resumen
La cianatión de alilo catalizada por el níquel de los alquinos produce hexadienenitriles sustituidos. Esta reacción, mejorada por los ácidos de Lewis, permite una mayor funcionalización en alcoholes o aminas y se ha aplicado a la síntesis de productos naturales.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Síntesis orgánica La síntesis orgánica.
- La catálisis de la catálisis.
Sus antecedentes:
- Los cianuros de alilo son precursores sintéticos muy versátiles.
- Las alquinas son bloques de construcción fundamentales en la química orgánica.
- Los métodos eficientes para la formación de enlaces carbono-carbono son cruciales para la síntesis de moléculas complejas.
Objetivo del estudio:
- Desarrollar un método catalizado por níquel para la adición de cianuros de alilo a las alquinas.
- Explorar el alcance y las limitaciones de la reacción de alilcianado desarrollada.
- Para demostrar la utilidad de la reacción en la síntesis de moléculas funcionalizadas y productos naturales.
Principales métodos:
- Reacción catalizada por níquel de los cianuros de alilo con varias alquinas.
- Uso de cocatalizadores de ácido de Lewis (AlMe2Cl o AlMe3) para mejorar la reactividad y el alcance del sustrato.
- Transformaciones del grupo funcional de los nitrilos de 2,5-hexadienenos resultantes.
- Aplicación de la reacción de carbocianado a la síntesis de plaunotol.
Principales resultados:
- Los 2,5-hexadienenitriles polisubstituidos fueron sintetizados con alta estereoselectividad y regioselectividad.
- Los cocatalizadores de ácido de Lewis aceleraron significativamente la reacción y ampliaron la compatibilidad del sustrato.
- El grupo ciano se convirtió con éxito en grupos hidroximetilo o aminometilo.
- Los cianuros alfa-siloxiallil permitieron la introducción de la funcionalidad del 3-oxo-propilo.
- La reacción de carbocianatión se aplicó a la construcción estereoselectiva de un enlace doble clave en el plaunotol.
Conclusiones:
- La catálisis de níquel/fosfina proporciona una ruta efectiva para la cianuración de alílico de las alquinas.
- La reacción ofrece una poderosa estrategia para la construcción de sistemas alilicos altamente sustituidos.
- La metodología es aplicable a la síntesis de productos naturales complejos como el plaunotol.
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