Department of Chemistry and INSTM Research Unit, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy.
Molecules. 2020 Jan 24;25(3):514. doi: 10.3390/molecules25030514.
The synthesis of several rigid, homochiral organic macrocycles possessing, respectively, average molecular and symmetries, is described. They have been obtained from aromatic dicarboxylic acids, in combination with an axially-chiral, suitable dibenzylic alcohol, derived from 1,1'-binaphthyl-2,2'-diol (BINOL) using one-pot esterification reactions in good isolated yields. NMR and circular dichroism (CD) spectroscopies detect the structural and shape variability in the scaffolds, reflected both in terms of the changes in chemical shifts and the shape of selected proton resonances, and in terms of the variation of the CD signature related to the dihedral angle defined by the binaphthyl units embedded in the rigid cyclic skeleton. The cyclic adducts are able to form stable complexes with aromatic diphenols, with binding strengths that are dependent on small variations in the spacing units, and therefore on the shapes of the internal cavities of the cyclic structures.
描述了几种刚性、同手性的有机大环的合成，它们分别具有平均分子和对称性质。这些大环是通过芳香族二羧酸与轴向手性的合适二苄基醇反应得到的，二苄基醇是由 1,1'-联萘-2,2'-二醇（BINOL）通过一锅酯化反应以良好的分离产率得到的。NMR 和圆二色性（CD）光谱检测到支架结构和形状的可变性，这反映在化学位移的变化和选定质子共振的形状上，以及与嵌入刚性环骨架中的联萘单元定义的二面角相关的 CD 特征的变化上。这些环状加合物能够与芳香族二酚形成稳定的配合物，其结合强度取决于间隔单元的微小变化，因此取决于环状结构内部腔的形状。
