134309-07-2Relevant academic research and scientific papers
Ditopic ion transport systems: Anion-π interactions and halogen bonds at work
Vargas Jentzsch, Andreas,Emery, Daniel,Mareda, Jiri,Metrangolo, Pierangelo,Resnati, Giuseppe,Matile, Stefan
supporting information; experimental part, p. 11675 - 11678 (2012/01/06)
Single-atom exchange series are introduced to extract the individual contributions of halogen bonds and anion-π interactions to the transport of anions across lipid bilayer membranes (see picture). Known cation binding sites are used for counterion activa
A convenient preparation of C-silylated calixarenes
Hudrlik, Paul F.,Hudrlik, Anne M.,Arasho, Wondwossen D.,Butcher, Raymond J.
body text, p. 2968 - 2976 (2009/04/06)
Calix[4]arenes having multiple silyl groups on the upper (wide) rim were prepared from the corresponding bromocalixarenes by halogen-metal exchange with t-BuLi followed by silylation. The best results were obtained using the clear supernatant from a mixtu
Selective arylmethylation, arylmethenylation and aroylation of mono- and tetra-p-cyano-methylcalix[4]arene
Sharma,Alam,Gutsche
, p. 1089 - 1096 (2007/10/02)
Tetra-p-cyanomethylcalix[4]arene (3) is selectively converted to its tetrabenzyl ethers 4 (1,3-alternate conformer) and 1,3-dibenzyl ethers 5 (cone conformer) by reaction with benzyl halides in the presence of variable amounts of potassium carbonate. Mono
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. 16. Functionalized Calixarenes: The Direct Substitution Route
Gutsche, C. David,Pagoria, Philip F.
, p. 5795 - 5802 (2007/10/02)
The base-induced condensation of p-phenylphenol and formaldehyde is shown to yield p-phenylcalixarene 3 and p-phenylcalixarene 5 as isolable products but no detectable amount of p-phenylcalixarene 1, contrary to earlier reports.As an alternative
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.
