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Hidroboración catalítica y enantioselectiva de los ciclopropenos

Marina Rubina¹, Michael Rubin, Vladimir Gevorgyan

¹Chemistry Department, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA.

Journal of the American Chemical Society

|June 12, 2003

Resumen

Los investigadores desarrollaron un nuevo método para crear boronatos quirales de ciclopropilo utilizando la catálisis del rodio. Esta técnica permite la síntesis de derivados ópticamente activos del ciclopropano para reacciones de acoplamiento cruzado.

Área de la Ciencia:

Química orgánica es la química orgánica.
La catálisis es la catálisis.
Metodología sintética de la metodología sintética.

Sus antecedentes:

Los derivados del ciclopropano son bloques de construcción valiosos en la síntesis orgánica.
La síntesis asimétrica de los boronatos de ciclopropano sigue siendo un desafío.
El desarrollo de métodos catalíticos eficientes para la síntesis enantioselectiva es crucial.

Objetivo del estudio:

Desarrollar una síntesis altamente diastereoselectiva y enantioselectiva de boronatos de ciclopropilo 2,2-disubstituidos.
Investigar los efectos de dirección de los sustituyentes en la hidroboración asimétrica.
Para demostrar la utilidad de los boronatos de ciclopropilo sintetizados en reacciones de acoplamiento cruzado.

Principales métodos:

Hidroboración asimétrica catalizada por el rodio de ciclopropenos 3,3-disubstituidos.
Utilizando los sustituyentes de éster y alkoximetilo como grupos de dirección.
Reacciones de acoplamiento cruzado de Suzuki con derivados ciclopropilborónicos seleccionados.

Principales resultados:

Se obtienen altos grados de diastereoselectividad y enantioselectividad en la síntesis de boronatos de ciclopropilo.
Demostró un fuerte efecto de dirección de los grupos éster y alkoximetilo, esenciales para la inducción enantiomérica.
Aplicación exitosa en el acoplamiento cruzado de Suzuki para obtener aril y vinilciclopropanos ópticamente activos.

Conclusiones:

La hidroboración asimétrica catalizada por el rodio proporciona una ruta efectiva hacia los boronatos quirales de ciclopropilo 2,2-disubstituidos.
La estrategia del grupo directivo es clave para lograr una alta enantioselectividad.
Los boronatos de ciclopropilo sintetizados son intermediarios versátiles para acceder a complejas estructuras quirales de ciclopropano.

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