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La cicloadición intramolecular [3 + 2] catalizada por el paladio de los alcalino-5-enilideneciclopropanos es una

Moisés Gulías¹, Rebeca García, Alejandro Delgado

¹Departamento de Química Orgánica y Unidad Asociada al CSIC, Universidad de Santiago de Compostela, Spain.

Journal of the American Chemical Society

|January 13, 2006

Resumen

Los complejos de paladio catalizan [3 + 2] las reacciones intramoleculares de cicloadición de los alcalino-5-enilideneciclopropanos. Este método eficiente construye rápidamente sistemas complejos de biciclo[3.3.0]octano con múltiples estereocentros.

Área de la Ciencia:

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

Sus antecedentes:

Las reacciones de cicloadición son fundamentales en la síntesis orgánica para la formación de estructuras cíclicas.
La catálisis con paladio ofrece vías versátiles para la formación de enlaces C-C y el ensamblaje de moléculas complejas.
Los andamios de biciclo[3.3.0]octano están presentes en varios productos naturales y compuestos farmacológicamente activos.

Objetivo del estudio:

Desarrollar una nueva reacción de cicloadición intramolecular catalizada por el paladio.
Para sintetizar de manera eficiente los derivados del biciclo [3.3.0] octano.
Para explorar las vías mecanicistas de la transformación observada.

Principales métodos:

Se utilizaron como sustratos los fácilmente accesibles alc-5-enilideneciclopropanos.
Se emplean complejos de paladio como catalizadores para promover la [3 + 2] cicloadición intramolecular.
Realizó cálculos teóricos preliminares para investigar los mecanismos de reacción.

Principales resultados:

Demostró el montaje rápido y eficiente de diversos sistemas de biciclo[3.3.0]octano.
Logró la formación de productos con hasta tres estereocentros.
Se han descubierto posibles vías mecánicas, incluida la reorganización concertada parecida al palada-eno y procesos escalonados con productos intermedios zwitteriónicos.

Conclusiones:

Estableció una nueva ruta sintética para sustituir los biciclo[3.3.0]octanos utilizando la catálisis del paladio.
La metodología proporciona acceso a marcos cíclicos estereoquímicamente ricos.
Las ideas mecánicas sugieren nuevas vías de reacción para las cicloadiciones mediadas por el paladio.

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