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Catálisis con diborón ((4) / piridina: Aplicación al amplio espectro [3 + 2] de la cicloadición de ciclopropanos y

Zhengwei Ding¹, Zhi Liu², Zhijun Wang³

¹Department of Medicinal Chemistry, School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China.

Journal of the American Chemical Society

|May 9, 2022

Resumen

Este estudio introduce un nuevo método catalítico que utiliza compuestos de diboro para reacciones de cicloadición de radicales de economía atómica. Este enfoque libre de metales permite una síntesis eficiente de derivados complejos de ciclopentano, ofreciendo una alternativa más ecológica a los métodos tradicionales.

Área de la Ciencia:

Química orgánica
Catálisis
Química ecológica

Sus antecedentes:

Los compuestos de tetraalcoxidiborón ((4) se utilizan típicamente estequiométricamente y no son reciclables.
Las reacciones de cicloadición [3+2] existentes a menudo se basan en catalizadores de metales de transición.

Objetivo del estudio:

Desarrollar un método atómico y catalítico utilizando compuestos de diboro.
Para permitir reacciones de cicloadición [3+2] sin metales con un alcance de sustrato más amplio.

Principales métodos:

Diseño de un ciclo catalítico para la cicloadición de radicales [3+2] con un cocatalizador de piridina.
Utilizando un compuesto de diboro comercial como catalizador.
Estudios mecánicos y de investigación computacional.

Principales resultados:

Ciclo catalítico exitoso para la cicloadición de radicales [3+2] utilizando diboro y piridina.
Condiciones libres de metales, catalizadores baratos y estables, y operación sencilla.
Ampliación del ámbito de aplicación del sustrato, incluidas las cetonas ciclopropílicas previamente no reactivas y los alquenos sustituidos.
Síntesis eficiente de diversos compuestos de ciclopentano con alto rendimiento y diastereoselectividad.
Aplicación en la síntesis formal de un medicamento antiobesidad y moléculas complejas similares a productos naturales.

Conclusiones:

Demuestra el primer uso catalítico de los compuestos de tetraalcoxydiboron (4).
Destaca una nueva catálisis de relevo de radicales de boronilo asistida por piridina.
Abre el camino para nuevas y eficientes reacciones orgánicas catalizadas por boro.

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