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Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
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Polimerización por adición de vinilo vivo y controlado catalizado con paladio de ciclopropenos
Zepeng Zhang1,2, Yunpeng Gao1, Shufeng Chen2
1Beijing National Laboratory of Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China.
Journal of the American Chemical Society
|October 14, 2021
Resumen
Este estudio demuestra una polimerización de adición de vinilo vivo para ciclopropenos (CPE) utilizando un catalizador de paladio. Este avance supera los desafíos anteriores, permitiendo la síntesis controlada de nuevos polímeros.
Área de la Ciencia:
- Química de los polímeros
- Síntesis orgánica
- Catálisis
Sus antecedentes:
- Los ciclopropenos (CPE) son bloques de construcción versátiles en la síntesis orgánica y la polimerización de la metástasis de apertura de anillo (ROMP).
- La polimerización por adición de vinilo de los CPE está poco explorada, siendo la polimerización viva/controlada un desafío significativo debido a la inestabilidad intermedia y las barreras de propagación.
Objetivo del estudio:
- Para lograr la polimerización de adición de vinilo vivo o controlado de 3-metil-3-carboximetil ciclopropenos (CPE).
- Investigar el sistema catalítico y el mecanismo que permite la polimerización controlada.
Principales métodos:
- Se utilizó un catalizador de paladio, específicamente [Pd(π-allyl) Cl]2, coordinado con un ligando de bisfosfina de sulfinamida.
- Se ha llevado a cabo la polimerización de 3-metil-3-carboximetil CPE.
- La cinética de polimerización analizada, el peso molecular (Mn) y la dispersión del peso molecular (Mw/Mn).
- Se realizó una copolimización de bloque controlada mediante adición secuencial de monómeros.
Principales resultados:
- Se demostró una relación lineal entre el peso molecular promedio numérico (Mn) y la conversión de monómeros.
- Se mantiene una dispersión de peso molecular estrecha (Mw/Mn) durante toda la polimerización.
- El Mn mostrado aumentó linealmente con la relación monómero-catalizador.
- Se logró con éxito la copolimización de bloque controlada, lo que confirma la naturaleza viva de la polimerización.
Conclusiones:
- El sistema desarrollado catalizado por paladio permite la polimerización de adición de vinilo vivo/controlado de ciclopropenos específicos.
- Los efectos sinérgicos entre el ligando catalizador y el grupo carbonilo del ciclopropeno son cruciales para lograr una polimerización controlada.
- Este método abre nuevas vías para sintetizar polímeros bien definidos a base de ciclopropeno.
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