Novel Bile Acid-Based Cyclic Bisimidazolium Receptors for Anion Recognition

Abstract

[structure: see text] Novel deoxycholic acid-based cyclic receptors, 3 and 4, containing two imidazolium groups and m-xylene and p-xylene as spacers have been synthesized. These receptors bind anions through hydrogen bonds utilizing two imidazolium (C-H)(+) and inwardly directed methylene hydrogens of both acetyl groups. Receptor 3 shows a moderate selectivity for fluoride ion whereas receptor 4 shows high affinity and selectivity for chloride ion in CDCl(3).

Di‐ and Tricationic Organic Salts: An Overview of Their Properties and Applications

“…The two receptors showed different selectivities and affinities toward the anions studied. The observed selectivity trend was [Cl – ] > [Br – ] > [F – ] > [CH 3 COO – ] > [I – ] for receptor 52 , containing a bigger cavity, whereas a trend [F – ] > [Cl – ] > [Br – ] > [CH 3 COO – ] > [I – ] was found for receptor 41 73…”

Synthesis and Evaluation of Cytotoxic Effects of Amino-ester Derivatives of Natural α,β-Amyrin Mixture

“…These findings were corroborated by the 13 C NMR data at d 53.1 (C 4' ), 138.6 (C 1" ), 128.5 (C 2" , C 3" , C 5" and C 6" ) and 127.4 (C 4" ). For the imidazole derivative, a slight modification in the synthesis was performed, which required DMF (dimethylformamide) as solvent 23 to lead 9a,b with 54% of yield. Their syntheses were corroborated by the appearance in the 1 H NMR spectra of signals at d 7.53 (1H, H 2" ), 7.11 (1H, H 4" ) and 6.96 (1H, H 5" ), while 13 C NMR spectra showed new signals at d 137.9 (C 2" ), 129.7 (C 4" ) and 199.9 (C 5" ).…”

Spectroscopic methods and theoretical studies of bromoacetic substituted derivatives of bile acids

“…selective N-1-alkylation of 2-thiouracil), 29 ammonium morpholinyl dithiocarbamate (selective S-alkylation), 30 N-1-alkylation of imidazole, 31 sodium azide [32][33][34] or tamoxifen (antagonist of the estrogen receptor in breast tissue). 35 In the case of sodium azide, the resulting products are used as substrates for click chemistry reactions.…”

“…Bile acids can react with halogenoacetic acid halides and potassium carbonate in chloroform or dichloromethane, with calcium or sodium hydride and tetrabutylammonium bromide (TEBA) in toluene, as well as pyridine or 4-(dimethylamino)pyridine (DMAP) in toluene. [27][28][29][30][31][32][33][34][35] These compounds were used in nucleophilic reactions with N-, S-or O-nucleophiles. In many cases bromo-or chloroacetyl substituted derivatives of bile acids react with pyrimidines (e.g.…”