Synthesis of novel biscalixarene-tube containing two kinds of calix[4]arene derivative units

A novel biscalixarene with two kinds of calix[4]arene derivative units connected by four bridging chains, was facilely＇ synthesized by ＂1 ＋ 1＂ condensation mode in high yield. The element analyses, ESI-MS, ^1H NMR and ^1H-^1H COSY spectrum showed that the calix[4]arene units of compound 4 were in cone conformations and compound 4 possessed biscalixarene-tube structure. 2007 Fa Fu Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.     

Metallic macrocycle with a 1,3-alternate calix[4]arene salicylideneamine ligand

The calix[4]arene-based podand which incorporates two salicylideneamine units in 1,3-alternate positions of the lower rim has been prepared and subjected to complexation studies with transition metal ions. The nickel and copper complexes form a 2 : 2 stoichiometric metallic macrocyclic framework.     

Synthesis of a novel fluorescent anthryl calix[4]arene as picric acid sensor

A novel and sensitive fluorescence sensor has been designed by click chemistry. Based on the obvious and selective fluorescence quenching of anthryl calix[4]arene, a sensitive and robust platform were developed for visual detection of picric acid (TNP) in the mixture of nitro aromatics. The computational calculations revealed the formation of host–guest complex driven by π–π stacking interactions.     

杯[4]芳烃单取代1,3-二酮衍生物的合成及生物活性研究

以杯[4]芳烃为原料经醚化和克莱森缩合两步反应首次合成杯[4]芳烃单取代1,3-二酮衍生物,其结构经1H NMR、13C NMR及MS表征。初步的HIV-1整合酶链转移反应活性测试结果表明,该杯[4]芳烃单取代1,3-二酮衍生物在测试浓度为25μM时其抑制率为12.67%。     

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, characterization and electrochemical properties of two new calix[4]arene derivatives bearing two ferrocene imine or ferrocene amine units at the upper rim

A novel calix[4]arene derivative with two ferrocenyl Schiff-base groups at the upper rim 3 has been synthesized from 5,17-diformyl-25,27-dipropoxy-26,28-dihydroxy calix[4]arene and 4-ferrocenylaniline via condensation reaction. Reduction of 3 with sodium borohydride led to calix[4]arene derivative 4 with two amino ferrocenyl groups at the upper rim. The ferrocenyl Schiff-base calix[4]arene and its corresponding reduced amine have been purified and characterized by elemental analysis,¹H NMR, FTIR, Mass and UV-vis spectral data. Electrochemical properties of compounds 3 and 4 have been investigated. Cyclic voltammograms of 3 and 4 show reversible redox couples of ferrocene/ferrocinium at E_1/2=0.401 V and 0.346 V, respectively. Electrochemical studies show these redox active compounds electrochemically recognize trivalent lanthanides La³⁺ and Ce³⁺ and divalent Pb²⁺ and Cu²⁺cations. With ferrocenyl Schiff-base calix[4]arene 3 an anodic shift as large as 130 mV is observed on addition of one equivalent of Ce³⁺ ion. Also extraction properties of compound 4 towards some metal cations have been described. It has been observed that compound 4 has a good selectivity for metal cations Fe³⁺, Cu²⁺, Pb²⁺ and Cd²⁺ against Ni²⁺ and Co²⁺.     

Synthesis and characterization of chiral catenanes based on rigid calix[4]arene

A new class of chiral calix[4]arene-based [2]catenanes was synthesized in excellent yields of 51-80%. They exhibit unique dynamic properties according to variable temperature NMR experiments. The enantiomeric pure (+)-catenane was prepared in 66% yield starting from (−)-calix[4]arene.     

一种新型杯[4]芳烃的合成

本文通过对特丁基杯[4]芳烃的酚羟基烷基化和苯环特丁基位上的IPSO-硝化制备了一系列对硝基杯[4]芳烃烷基醚,烷基分别是n-C~4H~9(3a)、n-C~8H~1~7(3b)、n-C~1~2H~2~5(3c)和n-C~1~6H~3~3(3d)。^1HNMR表明所有新的杯[4]芳烃都具有锥形(cone)构象。     

Synthesis and redox properties of novel ferrocenes with redox active 2,6-di-tert-butylphenol fragments: The first example of 2,6-di-tert-butylphenoxyl radicals in ferrocene system

Novel Schiff bases of ferrocenecarboxaldehyde bearing 2,6-di-tert-butyphenol fragments N-(3,5-di-tert-butyl-4-hydroxyphenyl)iminomethylferrocene (1) and N-(3,5-di-tert-butyl-4-hydroxybenzyl)iminomethylferrocene (2) have been synthesized and characterized. The oxidation of the compounds 1 and 2 by PbO₂ in solution leads to the formation of stable phenoxyl radicals 1′ and 2′ studied by EPR spectroscopy. The redox properties of ferrocenes 1 and 2 were studied using cyclic voltammetry.     

Synthesis of novel calix[4]arenes containing organosilicon groups

Metalation of (RSiMe₂)₃CH (1a R = H, 1b R = Me, 1c R = Ph) with lithium diisopropylamide (LDA) or methyllithium in THF gave organolithium reagents (RSiMe₂)₃CLi, which reacted with the formylated calixarene (2), to give the corresponding 5,17-bis[2,2-bis(organosilyl)-1-ethenyl]-25,26,27,28-tetrapropoxycalix[4]arenes (3a, 3b and 3c) via the Peterson olefination. The compounds (RSiMe₂)₃CLi were treated with 25,26,27,28-tetrakis(4-bromobutoxy)calix[4]arene (4) to give 25,26,27,28-tetrakis[4-(tris(dimethylsilyl)methyl)butoxy] calix[4]arene (5a) and 25,26,27,28-tetrakis[4-(tris(trimethylsilyl)methyl)butoxy] calix[4]arene (5b) via nucleophilic substitution reactions. However the compound 25,26,27,28-tetrakis[4-(tris(dimethylphenylsilyl)methyl)butoxy] calix[4]arene (5c) was not obtained, presumably because (PhSiMe₂)₃C- is highly sterically hindered and the reactivity of its derivatives is low. The compound 5a has potential as a core for dendrimers.     

Lanthanoid coordination with a tetrazole-substituted calix[4]diquinone and calix[4]dihydroquinone

The tetrazole-functionalised calixdiquinone 5,17-di-tert-butyl-26,28-bis-(1H-tetrazole-5-ylmethoxy)-calix[4]-25,27-diquinone Q was synthesised by chemical oxidation of the bis-tetrazole calix[4]arene precursor using PbO₂/HClO₄. The single crystal X-ray structure determination of Q confirmed the structure and showed binding of a water molecule in the solid state. Chemical reduction of Q to the dihydroquinone QR was achieved using N,N-diethylhydroxylamine. Comparison of the solution phase photophysical properties of Q or QR in the presence of terbium ions showed significant excitation only with QR, suggesting redox switching of the photophysical response may be possible with this or similar receptor.     

Synthesis, structure, and both cathodic and anodic reversible redox reactions of benzochalcogenophenes containing ferrocene units

2,3-Diferrocenylbenzo[b]thiophene and 1,3-diferrocenylbenzo[c]thiophene have been systematically and selectively synthesized from benzo[b]thiophene and phthaloyl dichloride, respectively. Characterization of the molecules was performed by physical and spectroscopic means and X-ray crystallographic analyses. The cyclic voltammograms of the novel thiophene derivatives containing ferrocene fragments showed a well-defined reversible cathodic step derived from the unusually stable thiophene radical anions and two distinct reversible anodic steps derived from ferrocenium cations separated from each other by a thiophene heterocycle. 1,3-Diferrocenylbenzo[c]selenophene was also synthesized in a similar manner for formation of 1,3-diferrocenylbenzo[c]thiophene by the use of bis(dimethylaluminum) selenide as a selenating reagent.     

The complexation of ferrocene derivatives by a water-soluble calix[6]arene

The complexation of several ferrocene derivatives by the water-soluble hostp-sulfonato-calix[6]arene was investigated using electrochemical and¹H-NMR spectroscopic techniques. The electrochemical results indicate that both oxidation states of the guests are bound to the calixarene host, although the oxidized (ferrocenium) forms are complexed more strongly than the reduced (ferrocene) species.¹H-NMR spectroscopic data indicate that the complexation phenomena involves the inclusion of the guest's ferrocene moiety into the flexible calixarene cavity.This paper is dedicated to the commemorative issue on the 50th anniversary of calixarenes.     

Synthesis and characterization of a stable copper (I) calix[4]dicyano-diimidazole complex

A new calix[4]dicyano-diimidazole ligand was prepared in two steps from a de-tert-butylated calix[4]arene. The corresponding Cu (I) complex was found to be remarkably stable. The X-ray structure of the latter revealed a mixture of both monomeric-mononuclear and dimeric-dinuclear complexes. Detailed investigations on this copper complex, involving NMR (VT and DOSY), Infra-red, and MS analyses, demonstrated that the dimeric-dinuclear complexe does not exist in solution. Despite the presence of two cyano binding groups on the calixarene platform, every attempts to isolate a stable Cu(II) complex failed.     

A [2]catenane containing an upper-rim functionalized calix[4]arene for anion recognition

A novel [2]catenane is synthesized in good yield from an upper-rim functionalized calix[4]arene macrobicycle and a nitro-substituted isophthalamide threading component in the presence of a chloride anion template via a ring-closing metathesis (RCM) reaction. After halide anion template removal the resulting catenane host exhibits a high degree of selectivity for chloride in competitive organic solvent mixtures.     

An excellent copper selective chemosensor based on calix[4]arene framework

The article depicts a detailed study regarding copper selective chemosensing and complexation nature of 5,11,17,23-tetrakis[(N,N-diphenylamino)methyl]-25,26,27,28-tetrahydroxycalix[4]arene (PAC4). Its photophysical characteristics in various solvents of different polarities along with the influence of acid and base on its spectral properties in these solvents are also discussed. The complexation affinity of PAC4 with regard to its latent applications as Cu(II) selective colorimetric and fluorescent sensor among the selected series of various cations such as Li(I), Na(I), K(I), Rb(I), Ba(II), Sr(II), Al(III), Fe(III), Cd(II), Co(II), Hg(II), Mn(II), Ni(II), Pb(II) and Zn(II) was examined by UV–visible and fluorescence emission spectroscopy in dichloromethane:acetonitrile (DCM:MeCN) solvent system. In addition, the process of complexation has been investigated through Job's plot and it has been observed that the complex between PAC4 and Cu(II) is formed in 1:1 stoichiometric ratio. The complex formation between PAC4 and Cu(II) has also been confirmed by FT-IR spectroscopy and thermal gravimetric analysis (TGA).     

Synthesis and electrochemical properties of calix[4]arene derivatives containing ferrocene units in the cone and 1,3-alternate conformation

Two novel calix[4]arene receptors containing ferrocene units in cone (L₁) and 1,3-alternate (L₂) conformations have been synthesized from 25,27-dihydroxy-26,28-bis[(3-aminopropyl)oxy]calix[4]arene 4 or 25,26,27,28-tetra[(3-aminopropyl)oxy]calix[4]arene 6 and ferrocenecarboxaldehyde via condensation, respectively. Their structures have been characterized by ¹H, ¹³C, APT, COSY NMR, FTIR, HSMR, and UV–vis spectral data. The electrochemical behavior of L₁ and L₂ has been investigated in the presence of F^?, Cl^?, Br^?, H₂PO₄^?, CH₃COO^? anions. Electrochemical studies show that these receptors electrochemically recognize CH₃COO^?, H₂PO₄^?, and Cl^?, anions. Using an UV–vis study, the selectivity to these anions in DMSO solution was confirmed.     

Synthesis and self-assembly of novel calix[4]arenocrowns: formation of calix[4]areno[2]catenanes

A series of novel calix[4]arenocrowns 1a-c were efficiently synthesized by a one-pot reaction of calix[4]monohydroquinone diacetate 5 with ditosylate 6 and its analogues in the presence of sodium hydroxide. It was found that the calix[4]arenocrowns could form stable pseudorotaxane-type complexes 2a-c with paraquat, and further self-assemble into calix[4]areno[2]catenanes 3a-c with dicationic salt 8 and p-bis(bromomethyl)benzene.     

Functionalisation of the upper rim of calix[4]arene via alcoholysis and hydrosilylation reactions

Metalation of 5,17-dibromo-25,26,27,28-tetra propoxy calix[4]arene (1) with n-BuLi in THF at −78 °C gave organolithium reagent, which reacted with Me₂HSiCl to give 5,17-bis(dimethylsilyl)-25,26,27,28-tetra propoxy calix[4]arene (2). The Si-H groups of calixarene 2 were treated with methanol, ethanol, propanol, butanol, pentanol, hexanol, 2-propanol and 2-methyl propanol in the presence of Karstedt catalyst (platinum(0)-1,3-divinyl-1,1,3,3-tetramethyl disiloxane complex, solution in xylene) to give the corresponding 5,17-bis(alkoxydimethylsilyl)-25,26,27,28-tetra propoxy calix[4]arene (3). Moreover, calixarene 2 was easily functionalized with a variety of alkenes using Karstedt catalyst to give the corresponding organosilylated calix[4]arene (4).