Important calixarene derivatives – their synthesis and applications

McMahon, Gillian; O'Malley, Shane; Nolan, Kieran; Diamond, Dermot

doi:10.3998/ark.5550190.0004.704

Cited by 72 publications

(10 citation statements)

References 31 publications

(40 reference statements)

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“…Calix[4]arenes are metacyclophanes having a hydrophobic cavity between the lower and upper rim, formed by four phenol units connected with methylene units [ 1 , 2 ]. Due to their numerous possibilities for functionalization on the upper as well as on the lower rim [ 3 ], this class of macromolecules is known for a wide range of applications [ 4 , 5 ]. Calix[4]arenes were found to act as biologically active compounds as they are used as antibacterial and even antimalarial agents or in cancer chemotherapy [ 6 , 7 , 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2022

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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+.

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Section: Introductionmentioning

confidence: 99%

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

et al. 2022

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“…Calixarenes and its conjugates are among most studied macrocyclic compounds. The compounds are non-toxic, non-immunogenicity, stable and easy to produce [87,88]. The cavity-shaped of calixarenes possess both hydrophobic and hydrophilic regions with upper rim, annulus and lower rim structures has contributes to their rigid conformation thereby act as host molecules.…”

Section: Chemical (Non-enzymatic) Based Assaysmentioning

confidence: 99%

A review on colorimetric methods for determination of organophosphate pesticides using gold and silver nanoparticles

et al. 2020

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This review (with 99 refs.) summarizes the progress that has been made in colorimetric (i.e. spectrophotometric) determination of organophosphate pesticides (OPPs) using gold and silver nanoparticles (NPs). Following an introduction into the field, a first large section covers the types and functions of organophosphate pesticides. Methods for colorimetric (spectrophotometric) measurements including RGB techniques are discussed next. A further section covers the characteristic features of gold and silver-based NPs. Syntheses and modifications of metal NPs are covered in section 5. This is followed by overviews on enzyme inhibition-based assays, aptamer-based assays and chemical (non-enzymatic) assays, and a discussion of specific features of colorimetric assays. Several Tables are presented that give an overview on the wealth of methods and materials. A concluding section addresses current challenges and discusses potential future trends and opportunities.

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“…Calix [n]arenes are cup-shaped macrocycles which can be synthesized as tetramers, hexamers, or octamers. 6 This class of compounds has wide applications including liquid crystal, 7 sensors, 8,9 stationary phase of chromatography 10 as well as a catalyst. 11 Calix[n]arenes have been proven to be a versatile host in host-guest catalysis to promote different chemical reactions and to work as useful greener recyclable micro-reactors in water, and in solvent-free conditions.…”

Section: Introductionmentioning

confidence: 99%

Novel Greener Microwave-Assisted Deprotection Methodology for the 1,3-Dioxolane Ketal of Isatin Using Calix[n]arenes

Barbosa¹,

Silva²,

Rezende³

et al. 2022

J. Braz. Chem. Soc.

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In this work, the combined use of p-sulfonic acid-calix[n]arene and microwave energy to hydrolyze the 1,3-dioxolane ketal of isatin was evaluated with excellent results. This is the first time that p-sulfonic acid-calix[n]arene has been used as the catalyst in a ketal hydrolysis reaction and the deprotection of the ketone carbonyl of isatin is reported. The presence of 2.5 mol% of p-sulfonic acid-calix[4,6]arene at 160 ºC resulted in over 96% conversion of this ketal in 10 min, with the additional advantage of using water as a solvent. This catalytic system (aqueous phase containing p-sulfonic acid-calix[4]arene) was reused for five consecutive cycles, with a conversion above 96% maintained. This reusable system is not practicable using p-toluenesulfonic acid and p-hydroxybenzenesulfonic acid as catalysts since both are extracted to the organic phase with the reaction product. The hydrolysis of 1,3-dioxolane ketal of isatins with different substituents (CH3, I, Br, Cl, F, NO2) in the aromatic ring was also evaluated. The protecting group of 5-methyl-isatin was removed with 73% conversion using 2.5 mol% of p-sulfonic acid-calix[4]arene at 160 ºC for 5 min. In contrast, the ketal of 5-nitro-isatin reached 80% conversion using the same conditions after 40 min.

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Important calixarene derivatives – their synthesis and applications

Cited by 72 publications

References 31 publications

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

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

A review on colorimetric methods for determination of organophosphate pesticides using gold and silver nanoparticles

Novel Greener Microwave-Assisted Deprotection Methodology for the 1,3-Dioxolane Ketal of Isatin Using Calix[n]arenes

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