Synthesis of upper rim calix[4]arene carcerands

The synthesis of novel tetra-olefinic calix[4]arene carcerands is described using a synthetic strategy involving palladium catalysed Heck coupling followed by imine formation.     

Synthesis and structure of lower rim C-linked N-tosyl peptidocalix[4]arenes

Chiral p-tert-butylcalix[4]arenes functionalized at the lower rim with amino acid residues have been prepared. The (1)H and (13)C NMR spectra indicate that the macrocycles preferably adopt a cone conformation. Calix[4]arenes bearing amino acid moieties were prepared as a class of receptors selective for anions that are bound through hydrogen bonding with the NH group. The association constants are dependent on the nature of the substituents at the lower rim. Derivative 9 shows the strongest complexation and the largest selectivity for N-tosyl-(L)-alaninate. Finally, a preliminary X-ray crystal study of the difunctionalized receptor 6f shows the "flattened cone" conformation in the solid state.     

Synthesis and capsule formation of upper rim substituted tetra-acrylamido calix[4]arenes

Upper rim substituted tetraiodo calix[4]arenes are coupled to a variety of acrylamides using the palladium catalysed Heck reaction. Tetra-acrylamido upper rim substituted calix[4]arenes are obtained in good yields with exceptionally high stereoselectivity, to produce the all-trans isomers. Tetra-acrylamido calix[4]arenes derived from secondary acrylamides are shown to dimerise via eight hydrogen bonds to form dimeric capsules, which are able to include small organic molecules.     

Selectively formylated and bridged calix[6]arene derivatives at the upper rim

The strategy of bridging the anisole units at the upper rim of calix[6]arene has been applied to strain the conformations of calix[6]arene. Based on the selective formylation of the 1,3,5-tri-p-tert-butylcalix[6]arene, several new calix[6]arene derivatives with different 1,3-bridged chains or a 1,3,5-tripod bridge at the upper rim have been prepared with moderate yields. The ¹H NMR spectra indicate that these calix[6]arene derivatives adopt a cone conformation, which has also been confirmed by the theoretical calculation at AM1 level. X-ray crystal structure of 1,3,5-tripod bridged compound 5 discloses that the calix[6]arene host stands in a cone conformation with approximate C_3v symmetry, and that a methanol molecule is enclosed in its hydrophobic cavity and stabilized by multi hydrogen bonds.     

State of water in CB[6] and CB[8] cavitands

The state of water in cucurbiturils CB[6] and CB[8], which were synthesized in hydrochloric acid solutions of glycoluril and formaldehyde, was studied. The amount of water coordinated in the macrocycle cavity and on its portals was shown to depend on the moisture content of the medium, being 2.4 molecules per 1 molecule of CB[6] and 3.2 per 1 molecule of CB[8], and in CB[8] coordinated water exists in two energy states. The state with the vaporization parameters Δ_vap H ^○ _381.5 = 29.2±0.4 kJ mol^?1 and Δ_vap S ^○ _381.5 = 50.7±1.0 J mol^?1 K^?1 coincides with the state of water in CB[6]. For another state, the vaporization parameters are Δ_vap H ^○ ₃₇₃ = 31.7±0.5 kJ mol^?1 and Δ_vap S ^○ ₃₇₃ = 63.2±1.2 J mol^?1 K^?1. The number of molecules bound to the oxygen atoms of the macrocycle portals is 1.7 and 2.6 for CB[6] and CB[8], respectively.     

Synthesis and reactivity of functionalized bridged m-xylylenedioxycalix[6]arenes

The synthesis of A,D-m-xylylene-bridged calix[6]arenes 1-8 functionalized at position 5 of the spacer arm is described. The cone conformation of the new bridged calix[6]arenes has been established by (1)H and (13)C NMR. The X-ray structure of compound 6 confirmed the cone conformation also in the solid state. Compounds 9 and 10, which are branched-like structures, were obtained by reductive amination of 5-amino-A,D-m-xylylene-bridged-B,C,E,F-tetra-O-ethylcalix[6]arene 7 with diformyl calix[4]arene and CTV derivatives 22 and 24, respectively.     

Synthesis of new trisulfonated calix[4]arenes functionalized at the upper rim, and their complexation with the trimethyllysine epigenetic mark

A synthetic route to produce a new family of trisulfonated calix[4]arenes bearing a single group, selectively introduced, that lines the binding pocket is reported. Ten examples, including new sulfonamide and biphenyl-substituted hosts, each with additional binding elements, demonstrate the tuning of guest affinities and selectivities. NMR titrations in phosphate-buffered water show that one of the new hosts binds to the modified amino acid trimethyllysine with the highest affinity and selectivity observed to date.     

Synthesis and structure of lower rim C-linked tetra-N-tosyl peptidocalix[4]arenes

Chiral p-tert-butylcalix[4]arenes perfunctionalised at the lower rim with amino acid residues have been prepared. The ¹H and ¹³C NMR spectra indicate that the macrocycles adopt a cone conformation. Calix[4]arenes bearing amino acid moieties 5a shows strong complexation towards Cl⁻, Br⁻, HSO₄⁻, H₂PO₄⁻ and N-tosyl-(l)-alaninate.     

Monosubstituted lower rim thiacalix[4]arene derivatives

A clean and partially green route to monoalkyled thiacalix[4]arenes has been demonstrated. We have discovered that tetraalkylammonium halide can cleave selectively one of the two aryl alkyl ethers of dialkylated para-tert-butylthiacalix[4]arenes. Thus, p-tert-butyl thiacalix[4]arenes differently monoalkyled at the lower rim with acetyl, propyl, and benzyl group were synthesized in good yield.     

Synthesis of calix[4]arene library substituted with peptides at the upper rim

A fluorescence-labeled calix[4]arene library substituted with peptides at the upper rim was synthesized. Screening of the library for binding a dye-labeled oligopeptide indicated that some peptidocalix[4]arenes selectively bind the oligopeptide. The chemosensitivity of the library members for a target peptide was also investigated.     

Regioselective upper rim substitution of calix[4]arenes

The electrophilic substitution of 25,27-dipropoxy-26,28-dinosyloxycalix[4]arene leads exclusively to the para-substitution of the alkylated phenol rings, while in the next step, the protecting nosyl group can be easily removed using a basic hydrolysis. The overall process yields dialkoxycalix[4]arenes with the substitution on the alkylated rings—the substitution pattern, which is complementary to the common dialkoxycalix[4]arenes with substituted nonalkylated phenolic units. The usefulness of this protection/deprotection procedure was documented by the synthesis of novel type of calixarene dipropoxy derivatives, and by the preparation of a novel anion receptor based on this substitution pattern.     

Synthesis of upper rim calix[4]arene divalent glycoclusters via amide bond conjugation

Synthetic routes for linking two sugar units at the upper rim of cone calix[4]arenes, through the formation of amide bonds, have been explored. Steric effects prevent the coupling of calix[4]arene dicarboxylic acid with simple aminoglycosides, whereas the corresponding reaction with carbohydrates bearing a two or three carbon atoms spacer, terminating with a primary amino group, allows the synthesis of several difunctionalized calix[4]arene neoglycoconjugates, attractive in chemical glycobiology and supramolecular chemistry.     

Synthesis of resorcin[4]arene cavitands by ring-closing metathesis

The synthesis and X-ray crystal structures of the first resorcin[4]arene cavitands by ring-closing metathesis reaction are described.     

羧基苯偶氮基杯[6]芳烃衍生物的合成及表征

近几年,随着对主客体化学研究的深入,杯芳烃的功能化修饰成为该领域的研究热点[1-6]。本文以邻、间、对氨基苯甲酸和杯[6]芳烃为原料,经重氮化 偶联反应合成了新型有色邻、间、对羧基苯偶氮基杯[6]芳烃,产物的结构经IR,1HNMR和元素分析表征;并研究了它们生色原理和光谱性能。结果表明它们是一类新型指示剂和具有新型配位空腔的主体分子。合成路线如下:图1　邻、间、对羧基苯偶氮基杯[6]芳烃的合成Fig.1　Fig1:Synthesisofp (o,m,p carboxylbenzeneazo)calix[6]arenes1　实验部分1 1　仪器与试剂Nicolet 460型傅里叶红外光谱仪(KBr…     

Synthesis and fluorescent properties of thiacalix[4]arenes containing terpyridyl fragments at the lower rim

New thiacalix[4]arenes tetrasubstituted by terpyridyl fragments at the lower rims in the 1,3-alternate stereoisomeric form were synthesized. The molecules interact with Eu^III and Tb^III in the DMF solution to form highly luminescent nanoscale (21–26 nm) metal-organic structures with the 2: 1 metal-to-ligand stoichiometry and a narrow particle size distribution.     

Recent advances in upper rim functionalization of resorcin[4]arene derivatives: Synthesis and applications

Abstract

During the last decades, resorcin[4]arenes have drawn much attention in the field of supramolecular chemistry because of their practical applicability in different areas. Therefore, many scientists have investigated this class of derivatives in recent years. In this article, we comprehensively reviewed a brief literature survey on the chemistry of upper rim functionalization of calix[4]resorcinarene derivatives and their applications concerning optical chemosensors, liquid crystal materials, host-guest systems, catalysis, drug delivery, biological activities, and analytical applications. This short review describes the survey of literature synthesis and upper rim functionalization of resorcin[4]arenes and their different application published in the last six years (2015–2020).     

Complexes of dirhodium(II) carboxylates with calix[4]resorcinarenes functionalized at the upper and lower rim of the molecule with P,N-containing Fragments

The features of the reaction between dirhodium(II) carboxylate and calix[4]resorcinarenes modified with various type functional groups at the upper and lower rim of the molecule in protic anhydrous solvent (ethanol) under inert atmosphere were investigated. Neutral complex compounds were isolated formed as a result of substitution of a water molecule by the macroligand in the axial position with respect to the R $ \tilde h The features of the reaction between dirhodium(II) carboxylate and calix[4]resorcinarenes modified with various type functional groups at the upper and lower rim of the molecule in protic anhydrous solvent (ethanol) under inert atmosphere were investigated. Neutral complex compounds were isolated formed as a result of substitution of a water molecule by the macroligand in the axial position with respect to the RRh bond occurring with the conservation of the latter. The compounds were characterized by 31P NMR, UV, IR, Raman, and ESR spectroscopy. Their composition was confirmed by elemental analysis. Original Russian Text ? E.V. Guseva, E.L. Gavrilova, A.A. Naumova, V.I. Morozov, N.I. Shatalova, D.T. Karimova, V.K. Polovnyak, 2008, published in Zhurnal Obshchei Khimii, 2008, Vol. 78, No. 12, pp. 1963–1971.     

Calix[4]resorcinols bearing γ-aminoacetal groups on the upper rim. Synthesis and properties

Synthesis of new calix[4]resorcinol molecules with acetal groups on the upper rim associated with calixarene skeleton through γ-aminoalkyl spacers was performed. The condensation of the compounds studied with 2-methylresorcinol was studied.     

Synthesis and structural characterisation of lower rim halogenated pyrogallol[4]arenes: bi-layers and hexameric nano-capsules

Two lower rim halogenated pyrogallol[4]arenes have been synthesised and structurally characterised as either bi-layer or hexameric nano-capsule motifs depending upon chain length and functionalisation.     

Thiacalix[4]arene derivatives with proximally bridged lower rim

New types of lower rim proximally bridged thiacalix[4]arenes have been prepared by direct aminolysis of starting tetraacetate derivative in the cone conformation using aliphatic α,ω-diamines. X-ray crystallography revealed the highly preorganized array of -C(O)NH- bonds resulting in strong intramolecular hydrogen bonding between amide groups of both bridges. The length of the corresponding diamine was found to have an essential influence on the yield of these bridged molecules.