基于四苯（硫）脲基双同系氧杂杯[4]芳烃受体的球形和线性阴离子的选择性结合。

Selective Binding of Spherical and Linear Anions by Tetraphenyl(thio)urea-Based Dihomooxacalix[4]arene Receptors.

机构信息

Centro de Química Estrutural, Faculdade de Ciências da Universidade de Lisboa , Edifício C8, 1749-016 Lisboa, Portugal.

Faculdade de Farmácia da Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.

出版信息

J Org Chem. 2017 Nov 3;82(21):11383-11390. doi: 10.1021/acs.joc.7b01801.

DOI:10.1021/acs.joc.7b01801

PMID:28990384

Abstract

Three novel tetra(thio)ureido dihomooxacalix[4]arene anion receptors (phenylurea 4a, phenylthiourea 4b, and tert-butylurea 4c) were synthesized and obtained in the cone conformation in solution, as shown by NMR studies. The X-ray crystal structure of 4c is reported. The host-guest properties of these receptors toward several anions were investigated by H NMR titrations. Phenylurea 4a displayed a very efficient binding toward the spherical F and Cl anions, and the linear CN (log K = 3.46, 3.50, and 4.02, respectively). In comparison to related bidentate phenylurea dihomooxacalix[4]arenes, tetraphenylurea 4a is more preorganized and the higher number of hydrogen bond donor sites provides a remarkable enhancement of its binding efficiency.

摘要

三种新型的四（硫代）脲二氢同杯[4]芳烃阴离子受体（苯脲 4a、苯硫脲 4b 和叔丁脲 4c）被合成，并通过 NMR 研究表明在溶液中呈锥形构象。报道了 4c 的 X 射线晶体结构。通过 1H NMR 滴定研究了这些受体对几种阴离子的主客体性质。苯脲 4a 对球形 F 和 Cl 阴离子具有非常有效的结合能力，对线性 CN 的结合常数分别为 3.46、3.50 和 4.02。与相关的双齿苯脲二氢同杯[4]芳烃相比，四苯脲 4a 具有更高的预组织性，并且更多的氢键供体位点显著提高了其结合效率。