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Síntesis y factores electrónicos en la ciclodimerización térmica de éteres trifluorovinílicos aromáticos

Bryan K Spraul¹, S Suresh, Jianyong Jin

¹Department of Chemistry and Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University, Clemson, South Carolina, USA.

Journal of the American Chemical Society

|May 25, 2006

Resumen

Se sintetizaron nuevos éteres aromáticos de trifluorovinilo y se ciclodimerizaron para formar compuestos de perfluorociclobutilo (PFCB). Se descubrió que los grupos de retirada de electrones disminuyen la velocidad de esta importante reacción de polimerización.

Área de la Ciencia:

Química orgánica es la química orgánica.
Química de Polímeros La Química de Polímeros es la química de los polímeros.

Sus antecedentes:

Los éteres trifluorovinílicos aromáticos son bloques de construcción muy versátiles.
Los enlaces de perfluorociclobutilo (PFCB) ofrecen propiedades materiales únicas.

Objetivo del estudio:

Para sintetizar nuevos éteres aromáticos de trifluorovinilo sustituidos por p.
Para investigar su ciclodimerización térmica a compuestos de PFCB.
Para explorar los efectos de los sustituyentes en la cinética de la reacción.

Principales métodos:

Preparación de 19 compuestos aromáticos de éter trifluorovinílico sustituidos por p.
Ciclodimerización mediada por radicales térmicos.
Análisis utilizando (19) F espectroscopia de RMN y la ecuación de Hammett.

Principales resultados:

Síntesis exitosa de compuestos difuncionales de PFCB.
Tolerancia demostrada del grupo funcional al intermediario del éter trifluorovinílico.
Efectos de sustitutos cuantificados en las tasas de ciclodimerización, con grupos de retirada de electrones que ralentizan la reacción.
Las constantes de reacción de Hammett calculadas (rho = -0,46 a 120°C, -0,59 a 130°C).

Conclusiones:

Los éteres trifluorovinílicos aromáticos pueden ser efectivamente ciclodimerizados a compuestos de PFCB.
Esta reacción es adecuada para crear monómeros para la polimerización de crecimiento gradual.
El estudio establece la primera relación lineal de energía libre para este proceso de ciclodimerización.

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