Browse
Submit Data
Databases
API
Help

Dataset Information

32 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Synthesis of deep-cavity fluorous calix[4]arenes as molecular recognition scaffolds.

ABSTRACT: Several lower-rim perfluoroalkylated (fluorous) calix[4]arenes have been synthesized by O-alkylation of the parent calix[4]arene. The compounds are formed in the cone conformation. They are soluble in several fluorous solvents and show promise for use in sensing, selective extractions and other applications.

SUBMITTER: Osipov M

PROVIDER: S-EPMC2587948 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Synthesis of Ionizable Calix[4]arenes for Chelation of Selected Divalent Cations.

Project description:Two sets of functionalised calix[4]arenes, either with a 1,3-crown ether bridge or with an open-chain oligo ether moiety in 1,3-position were prepared and further equipped with additional deprotonisable sulfonamide groups to establish chelating systems for selected cations Sr2+, Ba2+, and Pb2+ ions. To improve the complexation behaviour towards these cations, calix[4]arenes with oligo ether groups and modified crowns of different sizes were synthesized. Association constants were determined by UV/Vis titration in acetonitrile using the respective perchlorate salts and logK values between 3.2 and 8.0 were obtained. These findings were supported by the calculation of the binding energies exemplarily for selected complexes with Ba2+.

| S-EPMC8911665 | biostudies-literature

Heterometallic cobalt(ii) calix[6 and 8]arenes: synthesis, structure and electrochemical activity.

Project description:Heterometallic cobalt p-tert-butylcalix[6 and 8]arenes have been generated from the in situ reaction of lithium reagents (n-BuLi or t-BuOLi) or NaH with the parent calix[n]arene and subsequent reaction with CoBr2. The reverse route, involving the addition of in situ generated Li[Co(Ot-Bu)3] to p-tert-butylcalix[6 and 8]arene, has also been investigated. X-ray crystallography reveals the formation of complicated products incorporating differing numbers of cobalt and lithium or sodium centers, often with positional disorder, as well as, in some cases, the retention of halide. The electrochemical analysis revealed several oxidation events related to the subsequent oxidation of Co(ii) centers and the reduction of the metal cation at negative potentials. Moreover, the electrochemical activity of the phenol moieties of the parent calix[n]arenes resulted in dimerized products or quinone derivatives, leading to insoluble oligomeric products that deposit and passivate the electrode. Preliminary screening for electrochemical proton reduction revealed good activity for a number of these systems. Results suggest that [Co6Na(NCMe)6(μ-O)(p-tert-butylcalix[6]areneH)2Br]·7MeCN (6·7MeCN) is a promising molecular catalyst for electrochemical proton reduction, with a mass transport coefficient, catalytic charge transfer resistance and current magnitude at the catalytic turnover region that are comparable to those of the reference electrocatalyst (Co(ii)Cl2).

| S-EPMC9010074 | biostudies-literature

Anion responsive TTF-appended calix[4]arenes. Synthesis and study of two different conformers.

Project description:Two new cone- and 1,3-alternate-calix[4]arenes (cone-1 and 1,3-alt-1), bearing four modified TTF (tetrathiafulvalene) substituents on the upper rim, have been synthesized. The binding ability of these two sets of conformers for various anions, including F(-), Cl(-), Br(-), I(-), PF6(-), ClO4(-), HSO4(-), CH3COO(-), H2PO4(-), and HP2O7(3-), was tested in organic media by monitoring the changes in their UV/vis and (1)H NMR spectra as a function of added anion, as well as via cyclovoltammetry (CV) (all anions studied as their respective TBA salts). On the basis of the present findings, we propose that incorporation of four TTF units within an overall calix[4]arene-based recognition framework produces a preorganized receptor system that displays a modest preference for the pyrophosphate (HP2O7(3-)) anion.

| S-EPMC3133693 | biostudies-literature

Inherently chiral calix[4]arenes via oxazoline directed ortholithiation: synthesis and probe of chiral space.

Project description:The diastereoselective oxazoline-directed lithiation of calix[4]arenes is reported with diastereoselective ratios of greater than 100:1 in some instances. Notably, it has been found that the opposite diastereomer can be accessed via this approach merely through the choice of an alkyllithium reagent. The inherently chiral oxazoline calix[4]arenes have also been preliminarily examined as ligands in the palladium-catalyzed Tsuji-Trost allylation reaction, returning results comparable to their planar chiral ferrocene counterparts pointing towards future application of these types of compounds.

| S-EPMC4273304 | biostudies-other

Synthesis, Physicochemical Studies, Molecular Dynamics Simulations, and Metal-Ion-Dependent Antiproliferative and Antiangiogenic Properties of Cone ICL670-Substituted Calix[4]arenes.

Project description:Iron chelators, through their capacity to modulate the iron concentration in cells, are promising molecules for cancer chemotherapy. Chelators with high lipophilicity easily enter into cells and deplete the iron intracellular pool. Consequently, iron-dependent enzymes, such as ribonucleotide reductase, which is over-expressed in cancer cells, become nonfunctional. A series of calix[4]arene derivatives substituted at the lower rim by ICL670, a strong FeIII chelator, have been synthesized. Physicochemical properties and antiproliferative, angiogenesis, and tumorigenesis effects of two calix[4]arenes mono- (5a) or disubstituted (5b) with ICL670 have been studied. These compounds form metal complexes in a ratio of one to two ligands per FeIII atom as shown by combined analyses of the protometric titration curves and ESIMS spectra. The grafting of an ICL670 group on a calix[4]arene core does not significantly alter the acid-base properties, but improves the iron-chelating and lipophilicity properties. The best antiproliferative and anti-angiogenic results were obtained with calix[4]arene ligand 5a, which possesses the highest corresponding properties. Analyses of molecular dynamics simulations performed on the two calix[4]arenes provide three-dimensional structures of the complexes and proved 5a to be the most stable upon complexation.

| S-EPMC4293705 | biostudies-literature

Fluorous mixture synthesis of two libraries with hydantoin-, and benzodiazepinedione-fused heterocyclic scaffolds.

Project description:Diversity-oriented synthesis (DOS) and fluorous mixture synthesis (FMS) are two aspects of combinatorial chemistry. DOS generates library scaffolds with skeletal, substitution, and stereochemistry variations, whereas FMS is a highly efficient tool for library production. The combination of these two aspects in solution-phase synthesis of two novel heterocyclic compound libraries is presented in this paper. Mixtures of different fluorous amino acids undergo [3 + 2] cycloadditions followed by postcondensation reactions. The mixtures are then demixed by fluorous HPLC. Fluorous tags are removed by cyclization to afford hydantoin- and benzodiazepinedione-fused heterocyclic compounds as individual, pure, and structurally defined molecules. The application of MS-directed HPLC purification and parallel four-channel LC/MS analysis further increases the efficiency of FMS.

| S-EPMC1858674 | biostudies-literature

Correction: Inherently chiral calix[4]arenes via oxazoline directed ortholithiation: synthesis and probe of chiral space.

Project description:[This corrects the article DOI: 10.3762/bjoc.10.291.].

| S-EPMC5331270 | biostudies-literature

Synthesis of upper rim-double-bridged calix[4]arenes bearing seven membered rings and related compounds.

Project description:Meta/meta- and meta/para-disubstituted organomercury calix[4]arenes in the cone conformation were transformed into corresponding amino derivatives. Acylation and subsequent intramolecular cyclization using the Bischler-Napieralski reaction provided, in the case of the meta/meta-series, double bridged calixarenes possessing seven membered rings on the upper rim. A similar synthetic strategy applied to meta/para-isomers allowed for the isolation of monobridged compounds bearing an additional trifluoroacetamido group located distally to seven-membered rings. Both series represent inherently chiral systems, which were successfully resolved using preparative chiral HPLC. The pure enantiomers exhibited a recognition ability towards selected chiral guest molecules as documented by the 1H NMR titration experiments. The absolute configuration of the phenyl-substituted enantiomer (meta/meta-) was confirmed by single crystal structure determination (X-ray).

| S-EPMC9066730 | biostudies-literature

Synthesis of Ultrastable and Bioconjugable Ag, Au, and Bimetallic Ag_Au Nanoparticles Coated with Calix[4]arenes.

Project description:Compared to gold nanoparticles, silver nanoparticles are largely underexploited for the development of plasmonic nanosensors. This is mainly due to their easy chemical degradation through oxidation, poor colloidal stability, and usually broad size distribution after synthesis, which leads to broad localized surface plasmon resonance bands. Coatings based on polymers such as poly(ethylene glycol) (PEG) or poly(vinylpyrrolidone) (PVP) and plant extracts have been used for the stabilization of AgNPs; however, these thick coatings are not suitable for sensing applications as they isolate the metallic core. The examples of stable AgNPs coated with a thin organic layer remain scarce in comparison to their gold counterparts. In this work, we present a convenient one-step synthesis strategy that allows to obtain unique gold, silver, and bimetallic NPs that combine all of the properties required for biosensing applications. The NPs are stabilized by a tunable calix[4]arene-based monolayer obtained through the reduction of calix[4]arene-tetradiazonium salts. These multidentate ligands are of particular interest as (i) they provide excellent colloidal and chemical stabilities to the particles thanks to their anchoring to the surface via multiple chemical bonds, (ii) they allow the subsequent (bio)conjugation of (bio)molecules under mild conditions, and (iii) they allow a control over the composition of mixed coating layers. Ag and Ag_Au nanoparticles of a high stability are obtained, opening perspectives for development of numerous biosensing applications.

| S-EPMC8340414 | biostudies-literature

Molecular recognition and self-assembly special feature: Multipoint molecular recognition within a calix[6]arene funnel complex.

Project description:A multipoint recognition system based on a calix[6]arene is described. The calixarene core is decorated on alternating aromatic subunits by 3 imidazole arms at the small rim and 3 aniline groups at the large rim. This substitution pattern projects the aniline nitrogens toward each other when Zn(II) binds at the Tris-imidazole site or when a proton binds at an aniline. The XRD structure of the monoprotonated complex having an acetonitrile molecule bound to Zn(II) in the cavity revealed a constrained geometry at the metal center reminiscent of an entatic state. Computer modeling suggests that the aniline groups behave as a tritopic monobasic site in which only 1 aniline unit is protonated and interacts with the other 2 through strong hydrogen bonding. The metal complex selectively binds a monoprotonated diamine vs. a monoamine through multipoint recognition: coordination to the metal ion at the small rim, hydrogen bonding to the calix-oxygen core, CH/pi interaction within the cavity's aromatic walls, and H-bonding to the anilines at the large rim.

| S-EPMC2705605 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data