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Ciclopentanulación de enonas conjugadas utilizando un reactivo a base de vinildiazometano

Matthew Del Bel¹, Alexander Rovira, Carlos A Guerrero

¹Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, USA.

Journal of the American Chemical Society

|July 17, 2013

Resumen

Un nuevo método en dos pasos permite la ciclopentanulación de enonas utilizando un reactivo bifuncional. Esta química crea eficientemente anillos sustituidos de ciclopentanona, que sirven como una valiosa herramienta sintética.

Área de la Ciencia:

Química orgánica es la química orgánica.
Metodología sintética de la metodología sintética.
Síntesis asimétrica de síntesis.

Sus antecedentes:

Las reacciones de ciclopentanulación son cruciales para sintetizar moléculas cíclicas complejas.
El desarrollo de métodos eficientes y versátiles para la construcción de anillos de ciclopentanona sustituidos sigue siendo un área activa de investigación.
Los métodos existentes a menudo requieren múltiples pasos o reactivos especializados.

Objetivo del estudio:

Desarrollar una nueva estrategia sintética de dos pasos para la ciclopentanulación de enonas conjugadas.
Para utilizar un reactivo bifuncional, el metil 3-(tert-butyldimethylsilyloxy)-2-diazo-3-butenoate, para una eficiente formación de anillos.
Para demostrar la amplia aplicabilidad del método a varias enonas sustituidas.

Principales métodos:

Una secuencia de dos pasos que involucra una reacción Mukaiyama-Michael seguida por el acoplamiento diastereoselectivo alfa, alfa'-diketona.
Empleando metil 3-(tert-butyldimethylsilyloxy)-2-diazo-3-butenoate como un reactivo bifuncional clave, aprovechando sus funcionalidades de enol silano y diazoalcano.
Optimización de las condiciones de reacción para lograr altos rendimientos y diastereoselectividad.

Principales resultados:

Se logró la ciclopentanulación exitosa de las enonas di-, tri- y tetrasubstituidas.
El método proporciona un equivalente sintético efectivo para un "acetona 1,3-dipolo" sustituido.
Se observaron altos niveles de estereocontrol en el paso de acoplamiento diastereoselectivo.

Conclusiones:

El protocolo de dos pasos desarrollado ofrece una ruta eficiente y versátil para las ciclopentanonas sustituidas.
Esta metodología amplía la caja de herramientas sintéticas para construir estructuras carbocíclicas complejas.
El uso de un solo reactivo bifuncional simplifica la secuencia sintética y mejora la economía atómica.

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