Very Contracted to Extended <i>co</i>-Conformations with or without Oscillations in Two- and Three-Station [c2]Daisy Chains
作者:Camille Romuald、Eric Busseron、Frédéric Coutrot
DOI:10.1021/jo101234u
日期:2010.10.1
The syntheses of various two- and three-station mannosyl [c2]daisy chains, based on a dibenzo-24-crown-8 macrocyclic moiety and an ammonium, a triazolium, and a mono- or disubstituted pyridinium amide station, are reported. The ability of these molecules to act as molecular machine based mimetics has been further studied by 1H NMR studies. In all the protonated ammonium states, the interwoven rotaxane
据报道,基于二苯并-24-冠-8大环部分和铵,三唑鎓和单或二取代的吡啶鎓酰胺站,合成了两个和三个三甘露糖基[c2]雏菊链。这些分子充当基于分子机器的模拟物的能力已通过1 H NMR研究得到了进一步研究。在所有的质子化铵态中,交织的轮烷二聚体采用扩展的共构象。但是,铵站的氨基甲酰化导致许多其他[c2]菊花链协同作用-构型,取决于属于该轴的其他分子站。在包含铵和单或双取代吡啶鎓酰胺站的两站式[c2]雏菊链中,注意到交织组分的两个大幅度相对运动,并提供了伸长和收缩或非常收缩的状态,其中在后一种情况下,甘露吡喃糖从1 C 4到4 C 1的令人印象深刻的椅子状构象翻转。在包含铵,三唑鎓和双取代吡啶鎓酰胺的基于三工位的[c2]雏菊链的情况下,由于二苯并-24-冠8部分分别表示铵,三唑鎓和二取代的吡啶鎓酰胺。最终,在包含铵,三唑鎓和单取代吡啶鎓酰胺的车轴上,在质子化状态下观察到扩展的构象,而在NMR