62623-99-8Relevant articles and documents
Metal Ion Catalysis in Nucleophilic Substitution Reactions Promoted by Complexes of Polyether Ligands with Alkali Metal Salts
Gobbi, Alessandro,Landini, Dario,Maia, Angelamaria,Secci, Daniela
, p. 5954 - 5957 (1995)
Metal ion effects have been revealed on nucleophilic substitution reactions of n-octyl sulfonates 1-3 promoted by complexes of polyether ligands (PEGs, crown ethers, cryptands) with alkali metal salts MY (M = Li, Na, K; Y = I, Br) in low polarity solvents (chlorobenzene, o-dichlorobenzene, toluene) at 60 deg C.Rate constants increase, in the order K(+) M(+)) assists the departure of the leaving group ("electrophilic catalysis").
Bis-Cyclohexyl-Crown-Ethers as Allosteric Carriers
Costero, Ana M.,Rodriguez, Santiago
, p. 6265 - 6272 (2007/10/02)
Several bis-cyclohexyl-crown-ethers have been synthesized and used as carriers for alkaline cations.These compounds should all show negative allosteric cooperativity, but only 1 exhibits an odd cation transport behavior across the liquid organic membranes. Key words: Allosteric cooperativity; cation transport; crown-ethers; Na(1+)-K(1+)-ATPase; biological model.
STEREODESIGN OF CROWN ETHERS. I. SYNTHESIS AND (13)C NMR STUDY OF TRANS- CYCLOHEXANOCROWN ETHERS
Samoshin, V. V.,Zelenkina, O. A.,Subbotin, O. A.,Sergeev, N. M.,Zefirov, N. S.
, p. 413 - 418 (2007/10/02)
A series of trans-cyclohexanocrown ethers were synthesized by the intermolecular cyclization of polyethylene glycol trans-2-hydroxycyclohexyl ethers with the ditosyl derivatives of polyethylene glycols.A complete assignment of the signals in the (13)C NMR spectra was made for the obtained compounds.
Synthesis of Substituted Crown Ethers from Oligoethylene Glycols
Ikeda, Isao,Yamamura, Shingo,Nakatsuji, Yohji,Okahara, Mitsuo
, p. 5355 - 5358 (2007/10/02)
A convenient synthetic method for preparing 12-crown-4, 15-crown-5, 18-crown-6, and 21-crown-7 bearing various substituents by intramolecular cyclization of the corresponding substituted oligoethylene glycols in high yields is described.Substituents include modifiable pendent groups such as phenyl and hydroxymethyl, as well as various alkyl groups.Stability constants for the new substituted crown ethers with sodium and potassium ions in methanol were determined by potentiometric titration.The absolute effect of pendent groups on stability constants was insignificant.