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Las reacciones intramoleculares aniónicas diels-alder de los sistemas 1-arilo-4-oxahepta-1,6-diino en DMSO

Takayuki Kudoh¹, Tomoko Mori, Mitsuhito Shirahama

¹Department of Medical and Bioengineering Science, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Okayama, Japan.

Journal of the American Chemical Society

|March 30, 2007

Resumen

Las reacciones de cicloadición promovidas por bases de los sistemas de 4-oxahepta-1,6-diina forman eficientemente compuestos aromáticos policíclicos complejos. Este proceso aniónico intramolecular de Diels-Alder ocurre rápidamente a temperatura ambiente, produciendo diversos naftalenos sustituidos y heterociclos relacionados.

Área de la Ciencia:

Química orgánica es la química orgánica.
Química sintética de la química sintética.

Sus antecedentes:

Las reacciones de cicloadición son fundamentales en la síntesis orgánica.
Las reacciones intramoleculares de Diels-Alder ofrecen rutas eficientes a sistemas cíclicos complejos.
Los intermediarios aniónicos pueden permitir nuevas vías de reacción.

Objetivo del estudio:

Para investigar las reacciones de cicloadición promovidas por bases de los sistemas de 4-oxahepta-1,6-diino.
Para dilucidar el mecanismo del proceso intramolecular aniónico Diels-Alder.
Para demostrar la utilidad de este método para la síntesis de diversos compuestos aromáticos policíclicos.

Principales métodos:

Reacciones llevadas a cabo en dimetilsulfóxido (DMSO) bajo condiciones básicas.
Se utilizan sustratos de 1-arilo o 1-arilo-7 sustituidos por 4-oxahepta-1,6-diino.
Empleado cálculos de la Teoría Funcional de Densidad (DFT) para estudiar propiedades electrónicas.

Principales resultados:

La reacción intramolecular aniónica de Diels-Alder se desarrolla rápidamente a temperatura ambiente.
Se observa una alteración temporal de la aromaticidad, pero es reversible.
La formación de un anión alfa-arilalenida intermedio es clave.
Los cálculos de DFT indican que un aumento del nivel HOMO-1 del dieno aniónico facilita la reacción.
Se sintetizan varios naftalenos sustituidos, benzofuranos, fenantrenos y quinolinas.

Conclusiones:

La cicloadición promovida por la base de 4-oxahepta-1,6-diinas es un método eficiente para construir sistemas aromáticos policíclicos.
La reacción se produce a través de un mecanismo de Diels-Alder intramolecular aniónico fácil.
Esta vía proporciona un acceso rápido a valiosas arquitecturas heterocíclicas y biarílicas.

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