Bambusurils are recently developed neutral anion receptors that show a high affinity towards many inorganic anions, not only in organic solvents but also in water. However, the number of water-soluble bambusurils and also those bearing functional groups is very limited. In this paper we report the synthesis of four- and six-membered bambusurils containing eight and twelve nitro groups. All the nitro groups on the bambusuril portals could be transformed into amino functions, which provided the macrocycles with water solubility and allowed their further modification. For example, we have demonstrated the conversion of amino groups on the bambusurils into the corresponding urea-functionalized bambusuril derivatives. We also report the first example of a bambusuril bearing only two functional groups, which was prepared by the condensation of two different glycolurils.

中文翻译：

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含硝基的竹笋及其进一步改性

Bambusurils 是最近开发的中性阴离子受体，对许多无机阴离子表现出高亲和力，不仅在有机溶剂中，而且在水中。然而，水溶性竹笋的数量以及带有官能团的竹材数量非常有限。在本文中，我们报告了含有八个和十二个硝基的四元和六元竹荪的合成。bambusuril 门户上的所有硝基都可以转化为氨基官能团，这为大环提供了水溶性并允许它们进一步修饰。例如，我们已经证明了竹柳上的氨基转化为相应的脲官能化竹柳衍生物。我们还报告了第一个仅带有两个官能团的竹子的例子，