Estudios experimentales y computacionales sobre las reacciones catalizadas por Rh (I) de los siloxivinylciclopropanos y los diazoesters

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Sheng Feng¹, Kang Wang¹, Yifan Ping¹

¹Beijing National Laboratory of Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China.

Journal of the American Chemical Society

|December 4, 2020

Resumen

Las reacciones catalizadas por el rodio de los siloxivinilciclopropanos con diazoésteres producen ciclobutanos o dienos. La elección del catalizador dicta la selectividad del producto, con [Rh(cod) 2OTf] favoreciendo la formación de ciclobutano.

Área de la Ciencia:

Química organometálica
Catálisis
Síntesis orgánica

Sus antecedentes:

Los siloxivinylciclopropanos y los diazoesters son precursores sintéticos muy versátiles.
Los catalizadores de rodio se utilizan ampliamente en las transformaciones orgánicas.
El control de la quimioselectividad en las reacciones de ciclización es un desafío sintético clave.

Objetivo del estudio:

Para investigar la reacción catalizada por Rh (I) de los siloxivinilciclopropanos y los diazoesters.
Para explorar la influencia de diferentes catalizadores de rodio en la quimioselectividad de la reacción.
Para aclarar el mecanismo de reacción y comprender los efectos del catalizador.

Principales métodos:

Utilizando como catalizadores el [Rh (cod) Cl]2 y el [Rh (cod) OTf].
Empleando experimentos mecanicistas y cálculos de la Teoría Funcional de Densidad (DFT).
Analizando las distribuciones de productos y la estereoquímica.

Principales resultados:

La reacción produce siloxivinilciclobutano y derivados del 1,4-dieno.
[Rh (cod) Cl]2 favorece la formación de 1,4-dieno.
[Rh(cod) 2OTf] promueve la formación de siloxivinilciclobutano con alta quimioselectividad y produce isómeros de alqueno de configuración E.

Conclusiones:

La selección del catalizador es crucial para controlar la quimioselectividad en esta reacción.
Un mecanismo propuesto que involucra experimentos mecanicistas y cálculos DFT explica los resultados observados.
El estudio proporciona información sobre la síntesis controlada por catalizadores de los derivados de ciclobutano y dieno.

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