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Reducciones catalíticas [4 + 1]-cicloadiciones de vinilidenos y dienos

You-Yun Zhou¹, Christopher Uyeda²

¹Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.

Science (New York, N.Y.)

|February 23, 2019

Resumen

Los complejos de Dinickel catalizan nuevas reacciones de [4 + 1]-cicloadición, formando eficientemente anillos de cinco miembros a partir de 1,3-dienos y equivalentes de vinilideno. Este método ofrece una nueva ruta a valiosos compuestos cíclicos.

Área de la Ciencia:

Química orgánica
Química organometálica
Metodología sintética

Sus antecedentes:

Las reacciones de cicloadición son cruciales para sintetizar compuestos cíclicos.
Las reacciones de Diels-Alder forman fácilmente anillos de seis miembros, pero la síntesis de anillos de cinco miembros a través de la cicloadición está menos desarrollada.
Es esencial desarrollar nuevas estrategias de cicloadición para anillos de cinco miembros.

Objetivo del estudio:

Desarrollar nuevos métodos catalíticos para la síntesis de anillos de cinco miembros.
Explorar el uso de complejos de diníquel en reacciones de cicloadición.
Para investigar la formación de anillos de cinco miembros a través de la [4 + 1]-cicloadición.

Principales métodos:

Utilizando complejos de diníquel como catalizadores para las reacciones de [4 + 1]-cicloadición.
Generación de un equivalente de vinilideno a partir de la reducción del 1,1-dicloroalqueno con el zinc.
El uso de variantes de reacción intermolecular e intramolecular.
El uso de un ligando quiral C2-simétrico para la inducción asimétrica.

Principales resultados:

Los complejos de Dinickel catalizan con éxito las reacciones de [4 + 1]-cicloadición entre los 1,3-dienos y los equivalentes de vinilideno.
Se lograron cicloadiciones tanto intermoleculares como intramoleculares.
Se obtuvieron altos niveles de inducción asimétrica en las reacciones intramoleculares.

Conclusiones:

Este estudio introduce una nueva adición cíclica [4 + 1] catalizada por diníquel para la síntesis de anillos de cinco miembros.
La metodología proporciona una valiosa adición al kit de herramientas del químico sintético.
El uso de ligandos quirales demuestra el potencial para la síntesis enantioselectiva.

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