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Ciclización asimétrica de carbonilo-ene con catalización por ácido

Luping Liu¹, Markus Leutzsch¹, Yiying Zheng¹

¹Max-Planck-Institut für Kohlenforschung , Kaiser Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.

Journal of the American Chemical Society

|October 9, 2015

Resumen

Una nueva reacción catalizada por ácido de Brønsted crea anillos de cinco miembros a partir de moléculas simples. Este método ofrece una alta selectividad y rendimiento para sintetizar compuestos orgánicos complejos.

Área de la Ciencia:

Química orgánica
Catálisis
Síntesis asimétrica

Sus antecedentes:

Las reacciones intramoleculares de carbonileno son cruciales para la formación de compuestos cíclicos.
El desarrollo de métodos enantioselectivos para estas reacciones sigue siendo un desafío importante en la síntesis orgánica.

Objetivo del estudio:

Desarrollar una reacción de carbonilo intramolecular catalizada por el ácido de Brønsted altamente enantioselectiva.
Para sintetizar diversos anillos trans-3,4-disubstituidos carbo y heterocíclicos de cinco miembros.

Principales métodos:

Se utilizó un catalizador de imidodifosfato confinado para la reacción.
Se utiliza la activación electrófila de aldehídos con un catalizador quiral de ácido de Brønsted.
Productos caracterizados mediante técnicas como la resonancia magnética nuclear (RMN) y la espectrometría de masas por ionización por electrospray (ESI-MS).

Principales resultados:

Se obtienen altos rendimientos y buena a excelente diastereoselectividad y enantioselectividad.
Se ha sintetizado con éxito una serie de anillos trans-3,4-disubstituidos carbo y heterocíclicos de cinco miembros.
Demostró la utilidad del catalizador de imidodifosfato confinado para promover la reacción.

Conclusiones:

La reacción catalizada por ácido de Brønsted desarrollada proporciona una ruta eficiente para anillos de cinco miembros enriquecidos enantioméricamente.
Los estudios mecanicistas (ESI-MS, RMN, DFT) sugieren una vía gradual que involucra un nuevo intermediario covalente.
Esta metodología ofrece una herramienta valiosa para la síntesis de moléculas orgánicas complejas con un control estéreoquímico preciso.

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