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Hidroaminación catalizada por cobre: adición enantioselectiva de pirazoles a los ciclopropenos

Minghao Wang¹, Julie C Simon¹, Mengfei Xu¹

¹Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States.

Journal of the American Chemical Society

|June 30, 2023

Resumen

Este estudio introduce un nuevo método para sintetizar pirazoles quirales de N-ciclopropilo utilizando un catalizador de cobre abundante en la tierra. El proceso logra una alta estereoselectividad y regioselectividad en condiciones suaves.

Área de la Ciencia:

Química orgánica
Catálisis
Química Heterocíclica

Sus antecedentes:

Los pirazoles quirales de N-ciclopropilo son bloques de construcción valiosos en la química medicinal y la ciencia de los materiales.
La síntesis eficiente y estereoselectiva de dichos heterociclos sigue siendo un desafío.

Objetivo del estudio:

Desarrollar una ruta sintética novedosa, eficiente y estereoselectiva para los pirazoles quirales de N-ciclopropilo y los heterociclos relacionados.
Investigar el mecanismo de reacción y los factores de control de la regioselectividad y la estereoselectividad.

Principales métodos:

Utilizó un catalizador de cobre abundante en la tierra para la reacción de ciclización.
Se emplean condiciones de reacción suaves.
Se llevaron a cabo estudios experimentales y de teoría funcional de la densidad (DFT) para dilucidar el mecanismo.

Principales resultados:

Se obtiene un alto control regio-, diastereoselecto- y enantio en la síntesis.
Demostró una preferencia por la regioselectividad N2:N1, favoreciendo el nitrógeno más obstaculizado.
Identificó un mecanismo de aminocupración único de cinco centros.

Conclusiones:

El método desarrollado catalizado por cobre proporciona una vía eficiente para los pirazoles quirales de N-ciclopropilo.
El estudio ofrece información importante sobre los aspectos mecanicistas de la formación de pirazol.
Este enfoque es prometedor para la síntesis escalable de heterociclos quirales complejos.

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