Construction of Aromatic Multilayered Structures Based on the Conformational Properties of N,N’-Dimethylated Squaramide
Construction of Aromatic Multilayered Structures Based on the Conformational Properties of N,N’-Dimethylated Squaramide
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基于N,N-二甲基化方酰胺构象性质的芳香多层结构的构建
作者：
Arimura;M.; Tanaka;K.; Kanda;M.; Urushibara;K.; Fujii;S.; Katagiri;K.; Azumaya;I.; Kagechika;H.; Tanatani;A.
方酰胺是一种含有两个羰基和两个氨基的高刚性四元环体系，其衍生物在许多领域都有应用。我们合成了几种通过苯基连接的N，N‘-二甲基寡胺，并研究了它们在晶态和溶液中的结构。化合物1、2(双四方酰胺)和13(三方酰胺)在结晶状态下以折叠结构存在，其中芳环位于面对面的位置。在它们的多层结构中，苯环与InN，N‘-二甲基寡脲相比，更接近于平行，彼此更接近。间位连接的化合物2和13的单个分子显示出具有全Ror全轴手性的螺旋结构，但只提供外消旋晶体。核磁共振谱表明，这些化合物在溶液中保持了良好的折叠结构。N，N‘-二甲基方酰胺独特的空间和电子性质为合成新型功能芳香族多层螺旋折叠分子提供了可能。
Squaramide is a highly rigid four‐membered ring system bearing two carbonyl and two amino groups, and its derivatives have found applications in many fields. We synthesized severalN,N’‐dimethylated oligosquaramides linked via phenyl groups, and investigated their structures in the crystalline state and in solution. Compounds1,2(bissquaramides), and13(trissquaramide) exist as folded structures in the crystalline state, in which the aromatic rings are located in a face‐to‐face position. In their multilayered structures, the benzene rings are more nearly parallel and are closer to each other, compared with those inN,N’‐dimethylated oligoureas. Individual molecules ofmeta‐connected compounds2and13show a helical structure with all‐Ror all‐Saxis chirality, but afford only racemic crystals. The NMR spectra indicated that these compounds retain well‐ordered folded structures in solution. The unique steric and electronic properties ofN,N’‐dimethylated squaramide can provide access to novel functional aromatic multilayered and helical foldamers.