Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos s/n, Salamanca, 37008, Spain.
Servicio de Difracción de Rayos X, University of Salamanca, Plaza de los Caídos s/n, Salamanca, 37008, Spain.
Chemistry. 2021 Oct 21;27(59):14605-14609. doi: 10.1002/chem.202102137. Epub 2021 Sep 27.
Cleft type receptors showing the oxyanion hole motif have been prepared in a straightforward synthesis starting from the commercial 3,7-dihidroxy-2-naphthoic acid. The double H-bond donor pattern is achieved by the introduction of a sulfonamide group in the C-8 position of naphthalene and a carboxamide at the C-2 position. This cleft, for which the geometry resembles that of an oxyanion hole, is able to adjust to different guests, as shown by the analysis of the X-ray crystal structures of associates with methanol or acetic acid. Combination of hydrogen bonds and charge-transfer interactions led to further stabilization of the complexes, in which the electron-rich aromatic ring of the receptor was close in space to the electron-deficient dinitroaromatic guests. Modelling studies and bidimensional NMR experiments have been carried out to provide additional information.
已从商业 3,7-二羟基-2-萘甲酸出发，通过直接合成，制备了具有氧阴离子空洞模体的缝隙型受体。通过在萘的 C-8 位引入磺酰胺基和 C-2 位的羧酰胺基，实现了双氢键供体模式。该缝隙类似于氧阴离子空洞的几何形状，能够适应不同的客体，这可以通过与甲醇或乙酸形成的配合物的 X 射线晶体结构分析来证明。氢键和电荷转移相互作用的结合进一步稳定了配合物，其中受体富电子的芳环在空间上与缺电子的二硝基芳族客体接近。进行了建模研究和二维 NMR 实验，以提供更多信息。
