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Reacciones asimétricas Morita-Baylis-Hillman catalizadas por ácidos Brønsted quirales

Nolan T McDougal¹, Scott E Schaus

¹Department of Chemistry, Metcalf Center for Science and Engineering, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.

Journal of the American Chemical Society

|October 2, 2003

Resumen

Los ácidos Quiral Brønsted catalizan la reacción asimétrica Morita-Baylis-Hillman de la ciclohexenona con aldehídos, logrando altos rendimientos y enantioselectividades. Este trabajo presenta el primer método altamente enantioselectivo para esta importante transformación química.

Área de la Ciencia:

Química orgánica es la química orgánica.
Catalización asimétrica por catálisis asimétrica.

Sus antecedentes:

La reacción Morita-Baylis-Hillman (MBH) es una valiosa reacción de formación de enlaces carbono-carbono.
El desarrollo de variantes enantioselectivas es crucial para la síntesis de moléculas quirales.

Objetivo del estudio:

Desarrollar una nueva reacción asimétrica Morita-Baylis-Hillman enantioselectiva utilizando ácidos Brønsted quirales.
Para investigar la actividad catalítica de los ácidos de Brønsted derivados de BINOL en la reacción MBH de ciclohexeno con aldehídos.

Principales métodos:

Utilizó ácidos Brønsted quirales derivados de BINOL (2e o 2f) como catalizadores.
Empleó trietilfosfina como promotor nucleofílico.
Investigó la reacción de la ciclohexenona con varios aldehídos.

Principales resultados:

Se obtienen buenos a excelentes rendimientos (39-88%) para los productos de reacción MBH.
Se obtuvieron altas enantioselectividades, que oscilan entre el 67% y el 96% ee.
Demostró la eficacia de los ácidos quirales de Brønsted en la promoción de la enantioselectividad.

Conclusiones:

Este estudio informa la primera reacción asimétrica MBH altamente enantioselectiva de ciclohexeno con aldehídos catalizados por ácidos quirales de Brønsted.
El método desarrollado ofrece una nueva vía para la síntesis asimétrica de valiosos compuestos quirales.

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