Synthesis of Macrocyclic Stereoisomers Substituted with Oligolactide Fragments

© 2018, Pleiades Publishing, Ltd. Acylation of cone and 1,3-alternate stereoisomers of hydrazides of p-tert-butylthaicalix[4]arene tetrasubstituted at the lower rim with S,S-lactide in dimethylsulfoxide has afforded the macrocyclic oligolactide derivatives containing 16 (cone) to 24 (1,3-alternate) lactide fragments. It has been shown that nanosized aggregates (80 nm) are formed with silver nitrate in the case of the cone stereoisomer containing the oligolactide fragments at one side of the macrocyclic rim, whereas submicron particles (400 nm) are formed in the case of the 1,3-alternate conformation when the substituents are at different sides of the macrocycle

Supramolecular self-assembly of water-soluble nanoparticles based on amphiphilic p-tert-butylthiacalix[4]arenes with silver nitrate and fluorescein

New p-tert-butylthiacalix[4]arenes containing amide, ester, phthalimide and quaternary ammonium fragments in cone conformation were synthesized and characterized. The effective interaction of the p-tert-butylthiacalix[4]arenes with silver nitrate and fluorescein was shown by electron spectroscopy. As was shown by dynamic light scattering (DLS) all the macrocycles are able to form nanoscaled particles with silver nitrate. In the case of fluorescein, the formation of supramolecular assemblies was observed only for p-tert-butylthiacalix[4]arenes able of self-associating. It was shown that the interaction of nanoparticles based on the macrocycles and silver nitrate or fluorescein with bovine serum albumin (BSA) led to the formation of the particles of about 7. nm in size. © 2014 Elsevier B.V

Amphiphilic p-tert-butylthiacalix[4]arenes containing quaternary ammonium groups: From small molecules toward water-soluble nanoscale associates

Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd. The formation of supramolecular associates based on water-soluble p-tert-butylthiacalix[4]arenes with amino acids has been studied. It was shown that amphiphilic p-tert-butylthiacalix[4]arenes preferably formed supramolecular associates with aromatic α-amino acids (tyrosine and tryptophan). Increasing size of the substituents of p-tert-butylthiacalix[4]arenes led to increase molecular weight of supramolecular associates based on the macrocycles and "guest" molecules. The spatial structures of p-tert-butylthiacalix[4]arenes and their associates with phenylalanine were studied by two-dimensional 1H-1H nuclear Overhauser effect NMR spectroscopy. The ability of aggregates based on p-tert-butylthiacalix[4]arenes and amino acids to effectively interact with bovine serum albumin with the formation of 7- to 8-nm nanoparticles was shown

Design and applications of supramolecular systems based on (thia)calixarene ammonium derivatives

© 2017 by Nova Science Publishers, Inc. All rights reserved.Currently in supramolecular chemistry, much attention is devoted to scientific fields like molecular recognition, catalysis, self-assembly and nano-medicine which are essential in the development of science and industry. The design of synthetic receptors capable of recognizing different types of guests is a prerequisite in the construction of sensors, catalysts, biomimetic systems, selective extractants, drug delivery systems and programmable materials. The unique properties of (thia)calix[n]arenes (they exist in several configurations, the possibility of functionalizing them with different binding sites and the ability to fix these centers in the required spatial orientation) offer great opportunities in the design of synthetic receptors. The major setback of (thia)calixarene receptors is their poor solubility in water. However, introducing charged groups such as ammonium, phosphate, carboxylate and sulfonate enhances the water solubility of the macrocycles. The ammonium group is one of the most convenient synthetic fragments. This chapter describes a series of examples of introducing ammonium fragments into the (thia)calixarene platform, resulting in the production of ionic compounds: catalysts, receptors for cations, anions and various biological objects, such as DNA and proteins

Supramolecular "containers": Self-assembly and functionalization of thiacalix[4]arenes for recognition of amino- and dicarboxylic acids

New p-tert-butylthiacalix[4]arenes containing amide, tertiary amine and ammonium fragments in cone conformation were synthesized and characterized. The interaction of the p-tert-butylthiacalix[4]arenes with amino-, dicarboxylic acids and EDTA was studied by electron spectroscopy. The ability of the synthesized thiacalix[4]arenes to form supermolecules and supramolecular associates with guests was shown by dynamic light scattering. The formation of commutative and cascade supramolecular systems based on amphiphilic macrocycles was studied by UV spectroscopy and dynamic light scattering. It was shown that thiacalix[4]arene containing quaternary ammonium fragments with three methyl groups at the nitrogen form associates-"containers" containing glutamic acid as a guest

Effect of the alkylidene spacer and the p-tert-butylthiacalix[4]arene macrocyclic platform on the reactivity of the hydroxyl groups in the acylation reaction

© 2017, Pleiades Publishing, Ltd. A series of cone and 1,3-alternate p-tert-butylthiacalix[4]arenes tetrasubstituted at the lower rim simultaneously by the amide, ester, and carboxyl functions were synthesized. The reactivity of the synthesized compounds depends on the length of the alkylidene spacer. The N-(hydroxyethyl)amide derivatives do not react with succinic anhydride, whereas the N-(3-hydroxypropyl)amide derivatives react to form acylation products

Spatial Structure of Tetrasubstituted Thiacalix[4]arenes Containing L-Tryptophan Fragments in Solution

© 2018, Pleiades Publishing, Ltd. The steric structure of the cone and 1,3-alternate stereoisomers of p-tert-butylthiacalix[4]arenes bearing in the lower rim four substituents containing amide and ammonium groups as well as L-tryptophan residues was studied by 1Н, 13С, 1Н–1Н NOESY, and 1Н–13С HSQC NMR spectroscopy. The mutual repulsion of the charged ammonium groups and the presence of intramolecular hydrogen bonds in the synthesized compounds can make the peptide bond with the tryptophan residue sterically accessible for enzymes

New membrane carrier for glutamic acid based on p-tert-butylcalix[4]arene 1,3-disubstituted at the lower rim

Calix[4]arenes 1,3-disubstituted at the lower rim were synthesized and their receptor ability toward dicarboxylic, α-hydroxy and amino acids was investigated. A new synthetic receptor for glutamic acid based on 1,3-disubstituted calix[4]arene was suggested. © 2009

Towards macrocyclic ionic liquids: novel ammonium salts based on tetrasubstituted p-tert-butylthiacalix[4]arenes

© The Royal Society of Chemistry.Water-insoluble ionic liquids based on p-tert-butylthiacalix[4]arenes tetrasubstituted at the lower rim with amide and quaternary ammonium groups containing alkyl, phenyl, ester, phthalimide, glycine, alanine and glycylglycine groups in cone and 1,3-alternate conformations were synthesized. It was established that macrocycles containing quaternary ammonium fragments with alkyl, phenyl and ester groups at the nitrogen atom in cone conformation melt lower by 8-31 °C than 1,3-alternate stereoisomers. It was shown that the introduction of the bis(trifluoromethylsulfonyl)imide anion as a counterion in the structure of quaternary ammonium salts based on thiacalix[4]arenes led to a substantial decrease in the melting point of the above salts

Selective stepwise oxidation of 1,4-decamethoxypillar[5]arene

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. For the first time, the 1H and 13C{1H} NMR data were classified and analyzed for the pillar[5]arenes with one, two, three and five 1,4-benzoquinone fragments obtained in good yields. The empirical relationships established make it possible to define the relative position of the quinone and aryl fragments to each other in the oxidation products of any pillar[n]arenes