Introduction of methyl groups on vinylene segments of phenylene vinylene systems: synthesis and properties
作者:Khai Leok Chan、Alan Sellinger
DOI:10.1039/b909500d
日期:——
A facile synthetic route towards phenylene vinylene systems with methyl substituents at the vinyl linkages is demonstrated through palladium catalyzed Heck coupling of 1,4-diisopropenylbenzene with aryl bromides. The coupling leads to a series of model compounds that feature, in some cases, direct access to a trans-configuration at the double bonds. The oxidative stability of these systems is surprisingly unaffected by the presence of allylic C-H bonds in the methyl substituents. The methyl substituents modulate the electronic properties of the phenylene vinylene systems by inducing a significant twist to the conjugated backbone. The study suggests that the introduction of methyl groups at vinylene sites is a viable alternative to functionalising and tuning the properties of phenylene vinylene systems.
通过钯催化的Heck耦合反应,将1,4-二异丙烯基苯与芳基溴化物反应,展示了一条制备含有乙烯链上甲基取代基的苯并乙烯系统的简便合成路线。这种耦合反应产生了一系列模型化合物,在某些情况下,可以直接获得双键的反式构型。这些系统的氧化稳定性意外地不受甲基取代基中烯丙基C-H键的影响。甲基取代基通过在共轭骨架上引入显著扭曲,调节了苯并乙烯系统的电子性质。研究表明,在乙烯链位置引入甲基是一种有效的替代方法,用于功能化和调节苯并乙烯系统的性质。