135501-31-4Relevant academic research and scientific papers
Easy and selective method for the synthesis of Mono-, di-, tri-, tetra-O-arylmethyl-p-t-butylcalix[4]arenes
Xie, Yuanyuan,Xia, Wang
experimental part, p. 402 - 406 (2012/09/21)
Mono-, di-, tri- and tetra-O-arylmethyl-p-t-butylcalix[4]arenes were synthesised respectively from p-t-butylcalix[4]arene and arylmethyl bromide through an easy and selective one-step reaction. Mono- and di-arylmethyl ethers of p-t-butylcalix[4]arenes wer
Silver ion-selective electrodes using π-coordinate calix[4]arene derivatives as soft neutral carriers
Kimura, Keiichi,Yajima, Setsuko,Tatsumi, Kenta,Yokoyama, Masaaki,Oue, Masatoshi
, p. 5290 - 5294 (2007/10/03)
Calix[4]arene derivatives incorporating π-coordinate substituents such as allyl, benzyl, and propargyl groups were designed as soft neutral carriers for silver ion sensors. Most of all, tert-butylcalix[4]arene tetra(allyl ether) is an excellent neutral carrier for plasticized poly(vinyl chloride)-membrane silver ion-selective electrodes. The ion sensors showed high silver ion selectivity over alkali metal ions and also good selectivity against other soft metal ions such as lead and mercury(II) ions. The electrode potential response was as rapid as that for neutral-carrier-type alkali metal ion electrodes due to the soft interaction between π-coordinate substituants and silver ion, which was elucidated by 1H NMR spectroscopy.
An Easy Access to Tetra-O-Alkylated Calixarenes of Cone Conformation
Bitter, Istvan,Gruen, Alajos,Agai, Bela,Toeke, Laszlo
, p. 7835 - 7840 (2007/10/02)
Fully O-alkylated calixarenes have been synthesized by the alkylation of p-tert-butylcalixarene and its 1,3-dialkylated derivatives in liquid-liquid phase-transfer catalytic process. 1H4 and 1H2R2 could effeciently be deprotonated by aqueous NaOH (5
On the Origin of the Distal vs. Proximal Regioselectivity in Di-O-alkylation of Calixarenes
Araki, Koji,Iwamoto, Koji,Shigematsu, Satoshi,Shinkai, Seiji
, p. 1095 - 1098 (2007/10/02)
The mechanistic basis of the distal vs. proximal regioselectivity in di-O-alkylation of calixarene was investigated through the detailed product analyses.It was found that (i) the regioselectivity is profoundly affected by the residual intramolecular h
Calixarenes. 25. Conformations and Structures of the Products of Arylmethylation of Calixarenes
Gutsche, C. David,Reddy, P. Amruta
, p. 4783 - 4791 (2007/10/02)
The arylmethylations of calixarenes reported in this paper serve as companion pieces to an earlier study of the effects of reaction conditions and the structure of the derivatizing agent on the conformational outcome of the aroylation of calixarenes.In contrast to the aroylation reaction, where a significant and predictable relation is observed between the para substituent of the aroyl chloride and the ratio of conformers formed, the arylmethylation reaction shows only a small and much less easily predictable dependence of the conformer ratio on the para substituent of the arylmethyl halide.Also, whereas the products of aroylation are the cone and/or 1,3-alternate conformers, those of arylmethylation are the cone and/or partial cone conformers.While no rationale has yet emerged to explain this difference, a study of the benzylation of dibenzyl and tribenzyl ethers of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrahydroxycalixarene has established that the conformations of the tetraethers are not completely established until the third step in some cases and the fourth step in others.
CALIXARENES 9 CONFORMATIONAL ISOMERS OF THE ETHERS AND ESTERS OF CALIXARENES
Gutsche, C. David,Dhawan, Balram,Levine, Jeffrey A.,No, Kwang Hyun,Bauer, Lorenz J.
, p. 409 - 426 (2007/10/02)
Calixarene (1A), p-t-butylcalixarene (1B), and p-allylcalixarene (1C) have been converted to various derivatives, including the methyl, ethyl, allyl, benzyl and trimethylsilyl ethers and the acetates.Although the parent calixarenes exist preferentially in the cone conformation, they are conformationally flexible and at room temperature interconvert at a rate of ca 100 sec-1.All but the methyl ethers, on the other hand, are conformationally rigid at the room temperature.The preferred conformations in most cases are the cone and the partial cone, depending on the derivative formed (i.e. methyl and ethyl ethers favour the partial cone; benzyl and trimethylsilyl ethers favour the cone).In the cases of the allyl ethers and the acetates the p-substituents appear to influence the conformational outcome (i.e. 1A and 1B form the allyl ethers in the partial cone and cone conformation, respectively; 1A and 1B form the acatates in the 1,3-alternate and partial cone conformation, respectively).The conformationally rigid calixarene derivatives in the cone and partial cone conformations belong to the small group of synthetic compounds that contain a permanent cavity (a "changeless calix") whose dimensions are large enough to encapsulate other molecules.
