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Proceso radical asimétrico para la síntesis general de los ciclopropanos de heteroarilo quiral

Xiaoxu Wang¹, Jing Ke¹, Yiling Zhu¹

¹Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States.

Journal of the American Chemical Society

|July 20, 2021

Resumen

Un nuevo método catalítico utiliza la catálisis metaloradical (MRC) basada en cobalto para la ciclopropanación radical asimétrica. Este enfoque sintetiza de manera eficiente los ciclopropanos heteroariles quirales de los alquenos y los compuestos diazo.

Área de la Ciencia:

Química orgánica
Catálisis
Síntesis asimétrica

Sus antecedentes:

El desarrollo de métodos catalíticos eficientes para la síntesis asimétrica es crucial en la química orgánica.
La catálisis metaloradical (MRC) ofrece una vía única para la construcción de moléculas complejas.
Los ciclopropanos quirales son bloques de construcción valiosos en los productos farmacéuticos y la ciencia de los materiales.

Objetivo del estudio:

Desarrollar un método catalítico altamente eficiente para la ciclopropanación asimétrica de radicales.
Explorar el uso de la catálisis metaloradical basada en cobalto (II) con nuevos ligandos quirales.
Proporcionar acceso general a los valiosos heteroarilciclopropanos.

Principales métodos:

Se utiliza la catálisis metaloradical (MRC) a base de cobalto.
Se emplean amidoporfirinas quirales D2-simétricas recién sintetizadas como ligandos de apoyo.
Se ha investigado la ciclopropanación asimétrica de alquenos con α-heteroaryldiazometanos generados in situ.

Principales resultados:

Se obtienen altos rendimientos de heteroarilo ciclopropanos quirales.
Se han demostrado excelentes diastereoselectividades y enantioselectividades.
Demostró una amplia aplicabilidad a varios α-heteroaryldiazometanos y alquenos difíciles.

Conclusiones:

Estableció una metodología catalítica general y eficiente para la ciclopropanación radical asimétrica.
El sistema optimizado de Co (II) -MRC con amidoporfirinas quirales es muy eficaz.
Con el apoyo de datos computacionales y experimentales, se aclaró un mecanismo radical gradual que involucra radicales metalloalquilo clave.

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