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Catálisis de reacciones de cicloadición de azadieno heterocíclico por enlace de hidrógeno con disolvente: síntesis

Christopher M Glinkerman¹, Dale L Boger¹

¹Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States.

Journal of the American Chemical Society

|August 30, 2016

Resumen

Este estudio introduce un método catalítico general para las reacciones de Diels-Alder de demanda de electrones inversa utilizando perfluoroalcoholes como HFIP y TFE. Este enfoque activa azadienos heterocíclicos, lo que permite reacciones de cicloadición eficientes.

Área de la Ciencia:

Química orgánica
Catálisis
Química sintética

Sus antecedentes:

Las reacciones de Diels-Alder de demanda de electrones inversa que involucran azadienos heterocíclicos son difíciles de catalizar en general.
Los métodos tradicionales que usan ácidos de Lewis a menudo no activan los azadienos de manera efectiva, lo que lleva a reacciones secundarias improductivas.

Objetivo del estudio:

Desarrollar el primer método catalítico general para las reacciones de Diels-Alder de demanda de electrones inversa de azadienos heterocíclicos.
Demostrar la utilidad de los perfluoroalcoholes no nucleófilos como activadores en estas reacciones de cicloadición.

Principales métodos:

Utilizando el enlace de hidrógeno con disolventes de perfluoroalcoholes no nucleófilos, como el hexafluoroisopropanol (HFIP) y el trifluoroetanol (TFE).
El uso de estos perfluoroalcoholes para activar azadienos heterocíclicos con deficiencia de electrones para la cicloadición.

Principales resultados:

Catálisis exitosa de las reacciones de Diels-Alder de demanda de electrones inversa utilizando HFIP y TFE como disolventes activadores.
Se demostró la activación de azadienos heterocíclicos con deficiencia de electrones a través del enlace de hidrógeno con disolvente.
Se aplicó el método a una síntesis total concisa de metoxatina, utilizando la cicloadición de 1,2,3-triazina con enamina como paso clave.

Conclusiones:

El enlace de hidrógeno con disolventes con perfluoroalcoholes proporciona un método general y eficaz para catalizar las reacciones de Diels-Alder de demanda de electrones inversa de azadienos heterocíclicos.
Esta nueva estrategia catalítica supera las limitaciones de los métodos anteriores y permite una síntesis eficiente de moléculas complejas.

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