Substrate-selective dehydrocondensation at the interface of micelles and emulsions of common surfactants
Scratch the surface: Dehydrocondensations between carboxylates and amines by using an amphiphilic 1,3,5-triazinylammonium-based coupling agent were accelerated by the interfacial effect of micelles and emulsions of common surfactants (see figure). The reaction of carboxylates was promoted by both anionic and nonionic surfactants, and that of amines was promoted by only a nonionic surfactant. High selectivities for more lipophilic substrates were observed in micelles or emulsions. Copyright
Reaction of amphipathic-type thioester and amine with hydrophobic effect in water
The title reaction was studied using sodium 3-(1-oxododec-1-yl)thio- and 3-(1-oxohept-1-yl)thiopropanoate with various chain lengths of amines. The yields of the amides were found to depend on both the chain length of the thioester and that of amine, suggesting the presence of hydrophobic interaction. The amides were obtained in better yields after addition of sodium fluoride. Acylation (dodecanoylation) of some hydrophobic amino acids was also studied to obtain the corresponding amides. Georg Thieme Verlag Stuttgart - New York.
Torihata, Atsushi,Kuroda, Chiaki
experimental part
p. 2035 - 2038
(2011/10/09)
Catalytic properties of supramolecular systems based on polyoxyethylated calixarenes and amines
The rate of carboxylic ester cleavage by amphiphilic low-molecular-weight and polymeric amines in the presence of polyoxyethylated calix[4]arenes with different degrees of oxyethylation is determined by the formation of mixed aggregates, by the shift of pK a of the amine, and the character of the distribution of the reactants in functional micelles. All of the systems show a high substrate specificity. In the case of octyl- and decylamines, the reaction of p-nitrophenyl acetate is catalyzed and the reaction of more hydrophobic p-nitrophenyl laurate is inhibited. An opposite situation is observed in the systems based on branched polyethyleneimine: the reaction of p-nitrophenyl acetate is inhibited and the process involving p-nitrophenyl laurate is accelerated.
Aminolysis of carboxylic acid esters in direct, bicontinual, and inverse microemulsions based on cetyltrimethylammonium bromide
The reactivity of primary alkylamines in cleavage of p-nitrophenyl esters of carboxylic acids in microemulsions of different structures based on cetyltrimethylammonium bromide was studied. The aminolysis rate considerably increases in going from inverse to direct microemulsions, mainly owing to the concentration of the reactants in the boundary layer. 2005 Pleiades Publishing, Inc.
Effect of micellar surfactant solutions on the reactivity of long-chain amines
The kinetics of the interaction of long-chain alkylamines with p-nitrophenyl laurate in aqueous micellar solutions of cetylpyridinium bromide was studied. It was found that the reactivity of the amines changes when mixed aggregates are formed and that it depends on the ratio between components of the system. A nonlinear increase in the molecular packing density of the mixed micelles with the amine concentration was recorded by spin probe EPR.
Mirgorodskaya,Kudryavtseva,Zuev,Vylegzhanina
p. 1849 - 1852
(2007/10/03)
More Articles about upstream products of 69943-69-7