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The Synthesis of [Sn10(Si(SiMe3)3)4]2- Using a Metastable Sn(I) Halide Solution Synthesized via a Co-condensation Technique
Published on: November 28, 2016
Las vías de reacción de la reacción Simmons-Smith
Masaharu Nakamura1, Atsushi Hirai, Eiichi Nakamura
1Department of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. masaharu@chem.s.u-tokyo.ac.jp
Journal of the American Chemical Society
|February 20, 2003
Resumen
Este estudio investiga la ciclopropanación del carbenoide metálico utilizando cálculos de B3LYP. Las reacciones de carbenoides de zinc con alquenos son factibles a través de la transferencia de metileno, con la aceleración observada en las reacciones de alcohol aliloico.
Área de la Ciencia:
- Química computacional es la química computacional.
- Síntesis orgánica La síntesis orgánica.
- Química organometálica Química orgánica de los metales.
Sus antecedentes:
- La ciclopropanación es una reacción clave en la síntesis orgánica.
- Los carbenoides metálicos, como los reactivos Simmons-Smith, son ampliamente utilizados para la ciclopropanación.
- Comprender los mecanismos de reacción es crucial para optimizar las estrategias sintéticas.
Objetivo del estudio:
- Para dilucidar los mecanismos de reacción de la ciclopropanación de carbenoides metálicos.
- Para comparar la reactividad de los carbenoides de litio y zinc.
- Investigar los mecanismos de aceleración en la reacción de Simmons-Smith con alcohol aliloico y explorar la ciclopropanación diastereoselectiva.
Principales métodos:
- Cálculos de la teoría funcional de densidad (DFT) utilizando el funcional híbrido B3LYP.
- Modelado computacional de las vías de reacción, incluyendo la transferencia de metileno y la carbometalación.
- Análisis de estados de transición y energética de reacción.
Principales resultados:
- Los carbenoides de litio se someten rápidamente tanto a la transferencia de metileno como a la carbometalación.
- Los carbenoides de zinc favorecen la vía de transferencia de metileno experimentalmente factible.
- Se identificaron dos mecanismos de aceleración para la reacción de Simmons-Smith con alcohol aliloico: la migración de 1,2-cloro y una alternancia de enlace de cinco centros más fácil.
- La ciclopropanación dirigida por hidróxido de 2-ciclohexeno-1-ol fue modelada computacionalmente, apoyando las observaciones experimentales.
Conclusiones:
- El estudio computacional proporciona conocimientos mecanicistas sobre la ciclopropanación de carbenoides metálicos.
- Los hallazgos destacan las diferencias en la reactividad entre los carbenoides de litio y zinc.
- El estudio aclara los mecanismos de aceleración y modela las reacciones diastereoselectivas Simmons-Smith, ayudando en el diseño sintético.
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