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Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes
Published on: September 12, 2018
Inserción de alquino catalizado por paladio/reacción de Suzuki de yoduros de alquilo
Brendan M Monks1, Silas P Cook
1Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405-7102, USA.
Journal of the American Chemical Society
|September 11, 2012
Resumen
Este estudio introduce una nueva reacción catalizada por el paladio para sintetizar olefinas tetrasubstituidas estereodefinidas a partir de yoduros y alquinos alquilo no activados. El método permite una eficiente formación de enlaces carbono-carbono, evitando reacciones secundarias comunes como la eliminación del beta-hidruro.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis es la catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- Las olefinas tetrasubstituidas son valiosos intermediarios sintéticos.
- La síntesis de estas estructuras a menudo requiere condiciones difíciles o procedimientos complejos de varios pasos.
- Desarrollar métodos catalíticos eficientes para su construcción sigue siendo un desafío significativo.
Objetivo del estudio:
- Desarrollar un nuevo método catalizado por el paladio para la síntesis de olefinas tetrasubstituidas estereodefinidas.
- Para utilizar alquilo yoduros no activados como socios de acoplamiento en un ciclo catalítico.
- Para lograr la inserción selectiva de alquinos y el acoplamiento Suzuki en condiciones suaves.
Principales métodos:
- Reacción catalizada por paladio empleando la inserción de alquina seguida por el acoplamiento Suzuki.
- Utilizó ioduros de alquilo no activados y reactivos de organoboron.
- Investigar las condiciones de reacción para optimizar el rendimiento y la selectividad.
- Estudios mecanicistas realizados, incluido el análisis estereoquímico.
Principales resultados:
- Se logró una síntesis fácil de olefinas tetrasubstituidas estereodefinidas.
- La reacción inserta selectivamente las alquinas, impidiendo la eliminación del beta-hidruro.
- Se demostró un amplio alcance de sustrato tanto para los yoduros de alquilo como para los nucleófilos de boro.
- Los estudios mecánicos revelaron la inversión de la estereoquímica en el carbono que lleva el yoduro.
Conclusiones:
- El desarrollo de la reacción de inserción de alquina catalizada con paladio/reacción de Suzuki ofrece una ruta eficiente a las olefinas tetrasubstituidas.
- Esta metodología supera las limitaciones asociadas con la eliminación de ioduros de alquilo no activados y beta-hidruro.
- La reacción proporciona una plataforma versátil para la construcción de estructuras olefínicas complejas con estereoquímica controlada.
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