102088-39-1Relevant articles and documents
Br?nsted acidic magnetic nano-Fe3O4-adorned calix[n]arene sulfonic acids: Synthesis and application in the nucleophilic substitution of alcohols
Sayin, Serkan,Yilmaz, Mustafa
, p. 6669 - 6676 (2014)
Three magnetically recoverable Br?nsted acidic calix[n]arene derivatives were successfully constructed by immobilizing calix[n]arene sulfonic acids onto silica-coated magnetic nanoparticles, a process, which allows calix[n]arene derivatives to acquire magnetic properties. All of the magnetically recoverable Br?nsted acidic calix[n]arenes efficiently catalyze the coupling of electron-rich arenes with some alcohols in water. After separation and recovery from the reaction mixture by a simple magnet, these Br?nsted acidic calix[n]arenes can be recycled many times without losing their catalytic activity.
Insights into the structure of the supramolecular amphiphile formed by a sulfonated calix[6]arene and alkyltrimethylammonium surfactants
Basilio, Nuno,Martiin-Pastor,Garcia-Rio, Luis
, p. 6561 - 6568 (2012)
In this work, we have studied the interactions between the water-soluble p-sulfonatocalix[6]arene and cationic surfactants octyltrimethylammonium bromide below the cmc and dodecyltrimethylammonium bromide above the cmc, by saturation transfer difference (STD) NMR spectroscopy. From the STD build-up curves, we have obtained the T1 independent cross relaxation rates, and the results show that the interactions established between the cationic headgroup of the surfactant and the OMe group of the macrocycle play an important role in the stabilization of the complex, both below and above the cmc.
P-Sulfonic acid calix[n]arenes as homogeneous and recyclable organocatalysts for esterification reactions
Fernandes, Sergio Antonio,Natalino, Ricardo,Gazolla, Poliana Aparecida Rodrigues,Da Silva, Márcio José,Jham, Gulab Newandram
, p. 1630 - 1633 (2012)
Esterification yields were significantly improved using calix[n]arenes catalysts under simple conditions. p-Sulfonic acid calix[4]arene and p-sulfonic acid calix[6]arene were powerful organocatalysts in several esterification reactions, which showed activity comparable or even superior to other well-established acids catalysts, such as, sulfuric acid, p-toluenesulfonic acid, and p-hydroxybezenesulfonic acid described in the literature.
Synthesis and investigation of catalytic affinities of water-soluble amphiphilic calix[n]arene surfactants in the coupling reaction of some heteroaromatic compounds
Sayin, Serkan,Yilmaz, Mustafa
, p. 6528 - 6535 (2016)
Six water-soluble calix[n]arene-based Br?nsted acid-type catalysts with amphiphilic groups were successfully synthesized by incorporating sulfonic acid moieties. Their structures were characterized using FTIR,1H NMR,13C NMR, APT-NMR, and elemental analysis techniques. Moreover, their catalytic capabilities were evaluated in the coupling reaction of 2-methylfuran and/or N-methylindole with some sec-alcohols in aqueous media. The association of their surfactant abilities, and the effects of water amount used and reaction durations on the catalytic activities of these amphiphilic calix[n]arene derivatives were also investigated. Observations indicated that these amphiphilic calix[n]arene catalysts exhibited high catalytic activities in the coupling reactions of 2-methylfuran and N-methylindole with some alcohols in water.
Calix[n]arenes: Active organocatalysts for the synthesis of densely functionalized piperidines by one-pot multicomponent procedure
Palermo,Sathicq,Liberto,Fernandes,Langer,Jios,Romanelli
, p. 2049 - 2054 (2016)
An efficient, suitable and high yielding method has been developed for the synthesis of different densely functionalized piperidine derivatives via pseudo-five component, one-pot domino reaction through a combination of β-ketoesters, aromatic aldehydes, and various amines using p-sulfonic acid calix[n]arenes as catalysts. The reaction was carried out in refluxing methanol, affording very good yields of the expected piperidine. Atomic economy, environmentally benign procedure, reuse of catalysts, and short reaction time are some of the important features of this protocol.