ABSTRACT Cyclobis(paraquat-p-phenylene) (CBPQT4+) cyclophane represents an ideal π-electron deficient macrocycles, which demonstrates the extraordinary ability of hosting a variety of π-electron-rich guests in its rigid, preorganised cavity. However, this macrocycle undergoes large ring strain and therefore its preparation is often low yielding. In order to increase its yields, high-dilution conditions and template-directed synthesis are employed, which are rather time-consuming, i.e. a few weeks including template removal. Herein, we attempt to solve these problems by either using click reaction, or decreasing the ring strain by using a flexible linker. Three analogues of CBPQT4+ ring were synthesised without the need of guest template, each of which contains two bipyridinium units. Two of these three macrocycles are able to recognise π-electron rich guests within their cavities. However, the one obtained via click reaction demonstrates low guest recognition ability. Graphical Abstract

中文翻译：

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π-电子缺陷大环的有效合成

摘要 Cyclobis(paraquat-p​​-phenylene) (CBPQT4+) cyclophane 是一种理想的缺 π 电子大环化合物，它展示了在其刚性、预先组织的空腔中容纳各种富含 π 电子的客体的非凡能力。然而，这个大环经历了大的环应变，因此它的制备通常是低产的。为了提高其产率，采用了高稀释条件和模板导向合成，这相当耗时，即包括去除模板在内的数周时间。在这里，我们尝试通过使用点击反应或通过使用灵活的接头来减少环应变来解决这些问题。在不需要客体模板的情况下合成了三个 CBPQT4+ 环的类似物，每个类似物都包含两个联吡啶单元。这三个大环中的两个能够识别其腔内的富含 π 电子的客体。然而，通过点击反应获得的人表现出较低的客人识别能力。图形概要