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Química orgánica. Adiciones intermoleculares [2+2] catalizadas por el hierro de alceno no activado

Jordan M Hoyt¹, Valerie A Schmidt¹, Aaron M Tondreau¹

¹Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.

Science (New York, N.Y.)

|August 29, 2015

Resumen

La catálisis del hierro permite nuevas cicloadiciones [2+2] para sintetizar ciclobutanos a partir de alquenos simples. Este método catalizado por metales básicos expande las opciones de química sintética para crear valiosos compuestos cíclicos.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

Las reacciones de cicloadición, particularmente la reacción Diels-Alder [4 + 2], son fundamentales en la síntesis orgánica para la construcción de moléculas cíclicas.
La cicloadición de [2+2] alqueno para formar ciclobutanos se logra típicamente fotoquímicamente, pero sufre de un alcance limitado del sustrato y la compatibilidad del grupo funcional.

Objetivo del estudio:

Desarrollar una nueva reacción de cicloadición intermolecular [2+2] catalizada por hierro.
Ampliar la utilidad sintética de la formación de ciclobutano utilizando abundantes materias primas de hidrocarburos.
Lograr la síntesis regioselectiva y estereoselectiva de los ciclobutanos por medio de la catálisis de metales comunes.

Principales métodos:

Cicloadición intermolecular [2+2] catalizada por el hierro de alceno no activado.
Adición de ciclo cruzado catalizado por hierro de alquenos y dienos.
Diseño racional del ligando para optimizar el rendimiento del catalizador.

Principales resultados:

Desarrollo exitoso de reacciones de cicloadición [2+2] catalizadas por hierro para la síntesis de ciclobutano.
Demostración del control regional y estereoselectivo en los procesos de cicloadición.
Expansión del alcance del sustrato más allá de las limitaciones de los métodos fotoquímicos.

Conclusiones:

La catálisis del hierro proporciona una nueva y poderosa vía para la síntesis de ciclobutanos a través de cicloadiciones [2+2].
Este enfoque catalizado por metales comunes amplía el espacio químico accesible a partir de materiales de partida de hidrocarburos fácilmente disponibles.
La metodología desarrollada ofrece una alternativa más versátil y tolerante a las estrategias de cicloadición [2+2] existentes.

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