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Las adiciones catalíticas [5 + 1]-ciclónicas de los vinilciclopropanos y los vinilídenos

Conner M Farley¹, Kohei Sasakura¹, You-Yun Zhou¹

¹Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States.

Journal of the American Chemical Society

|February 22, 2020

Resumen

Los investigadores desarrollaron una nueva reacción catalizada por cobalto para crear estructuras específicas de ciclohexeno. Este método supera las limitaciones de la reacción de Diels-Alder para acceder a compuestos meta-sustituidos.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

La reacción de Diels-Alder generalmente sigue a la orto-para selectividad, lo que hace que los ciclohexenos meta-sustituidos sean difíciles de sintetizar.
El acceso a los ciclohexenos polisubstituidos con patrones de sustitución 1,3 (meta) presenta un desafío sintético significativo.

Objetivo del estudio:

Informar de una nueva reacción de reducción [5 + 1]-cicloadición catalizada por cobalto.
Para sintetizar metilenociclohexeno con todos los patrones de sustitución meta, superando las limitaciones de Diels-Alder.

Principales métodos:

Utilizando una [5 + 1]-cicloadición entre los equivalentes de vinilciclopropano y vinilideno.
Generación de equivalentes de vinilideno a partir de 1,1-dicloroalquenos utilizando el zinc como reductor.
Utilizando la catálisis de cobalto para facilitar la cicloadición.

Principales resultados:

Se han sintetizado exitosamente metilenociclohexenos con patrones de meta sustitución.
Demostró una nueva vía catalizada por cobalto para la construcción de andamios de ciclohexeno desafiantes.
La evidencia experimental apoya un mecanismo que involucra un intermediario de cobaltaciclobutano.

Conclusiones:

La cicloadición reductora catalizada por cobalto proporcionó una vía eficaz para todos los meticlohexenos sustituidos.
Esta metodología ofrece una alternativa valiosa a las reacciones tradicionales de Diels-Alder para acceder a isómeros específicos de ciclohexeno.
Los hallazgos amplían el alcance de las reacciones catalíticas de cicloadición en la síntesis orgánica.

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