Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2698–2709, doi:10.3762/bjoc.13.268

• complex formation. Interestingly, a fair upfield shift is observed also for the signals at 0.82 and 1.14 ppm (passing to 0.71 and 1.03 ppm, respectively) relevant to the propyl pendant groups linked at the 2, 8, 14 and 20 positions of the calixarene scaffold. Assuming for CAP the occurrence of an “all

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• water soluble catalysts [21], or to improve the water solubility of drug-chelate supramolecular assemblies (e.g., calixarene) [22][23]. The water solubility of phosphonic acid is strongly improved when the phosphonic acid is deprotonated (basic media). It is not rare to observe, when preparing NMR tubes

Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu²⁺

• Rahman Hosseinzadeh,
• Mohammad Nemati,
• Reza Zadmard and
• Maryam Mohadjerani

Beilstein J. Org. Chem. 2016, 12, 1749–1757, doi:10.3762/bjoc.12.163

• supramolecular structures, especially calixarene derivatives, has been an appealing field for research [14]. Calixarene has been considered as an effective molecular scaffold in the improvement of fluorescent and chromogenic sensors, especially for metal-ion recognition [14][15]. Calix[4]arene derivatives having

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• have reported the synthesis of ethylene-bridged phenothiazinophane 92 using the McMurry coupling reaction. Also cyclic voltammetry experiments indicated the intramolecular electronic communication between the phenothiazinyl subunits. Calixarene-based macrocycles bind with various metal ions. Lee and

Tuning of tetrathiafulvalene properties: versatile synthesis of N-arylated monopyrrolotetrathiafulvalenes via Ullmann-type coupling reactions

• Vladimir A. Azov,
• Diana Janott,
• Dirk Schlüter and
• Matthias Zeller

Beilstein J. Org. Chem. 2015, 11, 860–868, doi:10.3762/bjoc.11.96

• moieties directly attached to an aromatic calixarene backbone, we have chosen the copper-catalysed N-arylation reaction as a method for coupling of aromatic and MPTTF moieties with each other and successfully employed it for the preparation of two bis-MPTTF-calixarene conjugates, as well as two model low

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

• Simon A. Herbert,
• Laura J. van Laeren,
• Dominic C. Castell and
• Gareth E. Arnott

Beilstein J. Org. Chem. 2014, 10, 2751–2755, doi:10.3762/bjoc.10.291

• and applications. These range from their use as molecular receptors [2][3][4][5][6], stationary phase modifiers in separation science [7][8][9], and as molecular storage vessels [10][11][12][13]. In the area of molecular recognition, the importance of chirality in the calixarene receptor has been

• shown to be significant [14][15][16][17]. With this in mind, chiral calixarenes have been synthesized, either by the incorporation of a chiral group into the calixarene scaffold, or by the introduction of asymmetry into the structure itself, creating chirality associated with form and termed inherent

• reported in Table 2. The first thing we noted was that calixarene ligands 5 and 6 showed good activity, not only in returning excellent conversions to the product, but also in reducing the reaction time compared to that of the ‘flat’ model ligands (24 h vs 72 h). This observation was also noted by Dai and

Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

• Silvia Bernardi,
• Paola Fezzardi,
• Gabriele Rispoli,
• Stefania E. Sestito,
• Francesco Peri,
• Francesco Sansone and
• Alessandro Casnati

Beilstein J. Org. Chem. 2014, 10, 1672–1680, doi:10.3762/bjoc.10.175

• . Initially, two galactosylcalix[4]arenes were prepared starting from saccharide units and calixarene cores which differ in the relative dispositions of the alkyne and azido groups. Once the most convenient synthetic pathway was selected, two further lactosylcalix[4]arenes were obtained, one in the cone, the

• . Furthermore, we confirmed that in case of this specific lectin binding the presentation of lactose units on a cone calixarene is highly preferred with respect to its isomeric form in the 1,3-alternate structure. Keywords: glycocalixarenes; cluster glycoside effect; multivalency; click chemistry; surface

• hydrophilic spacers between the glycosyl units and the multivalent calixarene scaffold. We also report on preliminary studies of the interaction of the novel subfamily of galactosyl- and lactosylcalix[4]arenes with Gal-3 by surface plasmon resonance (SPR). Results and Discussion Synthesis of the

Low-generation dendrimers with a calixarene core and based on a chiral C₂-symmetric pyrrolidine as iminosugar mimics

• Marco Marradi,
• Stefano Cicchi,
• Francesco Sansone,
• Alessandro Casnati and
• Andrea Goti

Beilstein J. Org. Chem. 2012, 8, 951–957, doi:10.3762/bjoc.8.107

• of a considerable number of iminosugar-like moieties in a reduced volume and in a well-defined geometry. The inclusion of alkali-metal ions (sodium and potassium) in the polar cavity defined by the acetamide moieties at the lower rim of the calixarene was demonstrated, which allows also the

• calixarene core has only occasionally been explored. To the best of our knowledge, only one example in which a glycodendrimer was built on a calixarene core has been published [27], while no examples of iminosugar-based calixarene dendrimers have been reported so far. We report herein the synthesis of low

• -generation iminosugar-type calixarene-based dendrimers, demonstrating the feasibility of increasing the valency of the cluster by combining a dendrimeric arrangement of iminosugar ligands with a multivalent calixarene core. Results and Discussion We chose to address the conjugation of iminosugar-analogue

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• -tert-butyldihomooxacalix[4]arene (2) [5]. “Dihomo” implies two additional atoms in the bridge and “oxa” that one of them is oxygen. The remainder of the calixarene nomenclature denotes any substituents attached to the phenolic oxygens, known as the “lower rim”, and substituents found in the para

• –oxygen bond can be cleaved in the presence of fluoride, although this chemistry has yet to be explored. 3.1.5 Intramolecularly bridged derivatives: Linking two or more phenolic calixarene oxygen atoms together is a common method to improve selectivity and complex stability, and derivatives such as

• sites, such as the carbonyl group, strongly affects the binding ability of calixarene derivatives. Thus, the binding properties of derivatives containing esters, amides and ketones, have been assessed. Extraction studies performed under the same conditions as described above reported that cone ester 12a

Structural conditions required for the bridge lithiation and substitution of a basic calix[4]arene

• Conrad Fischer,
• Wilhelm Seichter and
• Edwin Weber

Beilstein J. Org. Chem. 2011, 7, 1602–1608, doi:10.3762/bjoc.7.188

• the lower-rim site as well as tert-butylated or non-tert-butylated upper-rim positions. Whereas this reaction fails for symmetric calix[4]arene ethers with alkoxy residues greater than methoxy, the carboxylation of mixed methoxy-propoxy calixarene ethers is possible. In connection with this, several

• new monobridge-substituted calix[4]arenes were characterized with respect to their conformational behaviour in solution and the X-ray crystal structure of one key intermediate is taken into consideration. Keywords: calixarene; lithiation; methylene bridge; supramolecular chemistry; X-ray structure

• that the type of substitution significantly influences the conformation of the calixarene core, which is a versatile and important feature of this compound type (Figure 1). Nevertheless, in all these attempts for the purpose of a bridge substitution, only p-tert-butyltetramethoxycalix[4]arene 2 (Scheme

Calix[4]arene-click-cyclodextrin and supramolecular structures with watersoluble NIPAAM-copolymers bearing adamantyl units: “Rings on ring on chain”

• Bernd Garska,
• Monir Tabatabai and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 784–788, doi:10.3762/bjoc.6.83

• Bernd Garska Monir Tabatabai Helmut Ritter Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany 10.3762/bjoc.6.83 Abstract We describe the calixarene-cyclodextrin-coupling via click reaction starting from

• (2) onto 6I-azido-β-CD (3) under microwave assisted conditions. Results and Discussion Synthesis and characterization of compound 4 The calixarene-click-CD compound (4) was synthesized as shown in Scheme 1. The successful microwave assisted cycloaddition of 5,11,17,23-tetra-tert-butyl-25,27

• calixarene units of 4 leads to a reduction of the cloud point temperature. Repeating the turbidity experiment at pH of 12, the cloud point temperature of the copolymer 5 decreased from the original 29 °C to 23 °C due to salt and pH effects [18]. However, after adding the calixarene-click-cyclodextrin (4) to

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

Synthesis and properties of calix[4]arene telluropodant ethers as Ag⁺ selective sensors and Ag⁺, Hg²⁺ extractants

• Yang Lu,
• Yuanyuan Li,
• Song He,
• Yan Lu,
• Changying Liu,
• Xianshun Zeng and
• Langxing Chen

Beilstein J. Org. Chem. 2009, 5, No. 59, doi:10.3762/bjoc.5.59

• functionalized calixarenes in recent years [1][2][3][4]. In fact, a large number of calixarene derivatives containing pendant ether, amide, ketonic, ester and crown ether groups have been employed in studies of ISEs sensitive to sodium ions [11][12][13][14][15][16][17][18][19][20], potassium ions [21][22][23][24

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

• Maksim Osipov,
• Qianli Chu,
• Steven J. Geib,
• Dennis P. Curran and
• Stephen G. Weber

Beilstein J. Org. Chem. 2008, 4, No. 36, doi:10.3762/bjoc.4.36

• 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. Keywords: calixarene; fluorous; hydrofluoroethers

• have included nanowires [3], self organized nanostructures [4] chiral supramolecular assemblies [5], as well as sensors for cations [6][7], anions [8] and neutral organic molecules [9]. The versatility of the calixarene scaffold is a result of its preorganized cavity [10], which consists of four

• calixarene can be tailored to bind preferentially with specific target guest molecules. Fluorous chemistry [13] has become an increasingly popular field as a result of the multitude of applications that it has provided across the disciplines of chemistry. Fluorocarbons are extraordinarily non-polar and are