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[3+2] cicloadiciones de cetonas de arilo ciclopropilo por fotocatálisis con luz visible

Zhan Lu¹, Meihua Shen, Tehshik P Yoon

¹Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.

Journal of the American Chemical Society

|January 11, 2011

Resumen

Los investigadores desarrollaron un nuevo método fotocatalítico para sintetizar ciclopentanos sustituidos. Este enfoque utiliza cetonas y olefinas de aril ciclopropilo, iniciando con la formación de aniones del radical cetónico a través de la reducción de un electrón.

Área de la Ciencia:

Química orgánica es la química orgánica.
La fotocatálisis por fotocatálisis.
Metodología sintética de la metodología sintética.

Sus antecedentes:

Los anillos de ciclopentano son motivos estructurales frecuentes en productos naturales y productos farmacéuticos.
Los métodos eficientes para construir ciclopentanos altamente sustituidos son cruciales para la química sintética.
Las rutas sintéticas existentes pueden carecer de versatilidad o requerir condiciones duras.

Objetivo del estudio:

Introducir una nueva reacción formal [3+2] para la síntesis de ciclopentano.
Desarrollar un método fotocatalítico utilizando materiales de partida fácilmente disponibles.
Para lograr altos niveles de sustitución en los anillos de ciclopentano resultantes.

Principales métodos:

Empleando un sistema fotocatalítico que incluye rutenio ((II) tris ((bipiridina) ([Ru ((bpy) 3) ((2+)), triflato de lantano (La ((OTf) 3) y tetrametiletilendiamina (TMEDA).
Utilizando cetonas de aril ciclopropil y olefinas como socios clave de la reacción.
Iniciar la reacción a través de la reducción de un electrón de la cetona a un anión radical.

Principales resultados:

Generación exitosa de sistemas de anillos de ciclopentano altamente sustituidos.
Demostración de una nueva vía formal [3+2] de cicloadición.
El sistema fotocatalítico promueve efectivamente la formación intermedia del anión radical clave.

Conclusiones:

El método reportado proporciona una ruta eficiente y versátil a los ciclopentanos sustituidos.
La fotocatálisis ofrece una estrategia suave y efectiva para la formación de enlaces C-C.
Este trabajo amplía el conjunto de herramientas para la construcción de estructuras cíclicas complejas.

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