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El control de reactivos permite la apertura selectiva y regional de iones fenónicos asimétricos

Shiyan Xu¹, Hannah M Holst¹, Shelby B McGuire¹

¹Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States.

Journal of the American Chemical Society

|April 22, 2020

Resumen

Los investigadores lograron una apertura selectiva y divergente de iones de fenonio utilizando iones de cloruro. La adición controlada de cloruro de los ácidos de Lewis tetracloruro de estaño (SnCl4) y tetracloruro de titanio (TiCl4) permite la síntesis de diversos productos.

Área de la Ciencia:

Química orgánica
Mecanismos de reacción
Catálisis

Sus antecedentes:

Los iones fenonio son intermediarios clave en las reacciones de sustitución aromática electrófila.
El control de la regioselectividad de la apertura de iones de fenonio es crucial para las aplicaciones sintéticas.
Los iones fenonio asimétricos presentan desafíos debido a múltiples sitios reactivos.

Objetivo del estudio:

Informar sobre los primeros ejemplos de apertura selectiva y regiodivergente de iones de fenonio no simétricos.
Demostrar el doble papel del tetracloruro de estaño (SnCl4) y el tetracloruro de titanio (TiCl4) como ácidos de Lewis y nucleófilos del cloruro.
Para mostrar el control del reactivo sobre la adición de cloruro en posiciones específicas del ion fenonio.

Principales métodos:

Utilizando SnCl4 y TiCl4 como catalizadores y fuentes de cloruro.
Investigando la reacción de iones de fenonio no simétricos con iones de cloruro.
Analizando la regioselectividad y la estereospecificidad de las reacciones de apertura de anillos.

Principales resultados:

Se ha conseguido una apertura selectiva y regiodivergente de iones fenónicos asimétricos.
Se ha demostrado que SnCl4 dirige la adición de cloruro a la posición interna sustituida.
Se demostró que TiCl4 dirige la adición de cloruro a la posición terminal no sustituida.
Se obtienen buenos a excelentes rendimientos con alta selectividad y estereospecificidad.

Conclusiones:

El método desarrollado ofrece un control preciso de la apertura de iones de fenonio.
El doble papel de SnCl4 y TiCl4 proporciona un enfoque versátil para sintetizar diversos productos.
Estas reacciones son operacionalmente simples y altamente eficientes, con una amplia utilidad del producto.

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