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0220U101966,
0119U101104
,
Experimental and theoretical study of the nucleophilicity of amines and tetraalkylammonium salts in the ring-opening reactions of oxirane
Shved Elena M., Доктор хімічних наук
28-02-2020
Vasyl' Stus Donetsk National University
The structure effect of catalysts (tertiary amines and tetraalkylammonium salts) on the nucleophilic oxirane ring opening by carboxylic acids at 323-343 K has been established by kinetic, spectral, quantum chemical, correlation methods. The kinetic characteristics and activation parameters of the reaction in the system "epichlorohydrin - proton donor - catalyst" have been determined. The structure effect of the halide and carboxylate anions and their salts with alkali metals on the rate of the oxirane ring opening has been investigated by quantum chemical method. The equilibrium configurations of reactants, transition states and products of the reaction of epichlorohydrin with halide and carboxylate anions of various structure have been found. According to the More O'Ferrall - Jencks diagram, it has been shown that the transition states of the reaction pathway have the dissociative nature. It has been established that the nucleophile's backside attack on ?-atom of substrate is more effective. It has been determined that the increase in steric hindrances (TSEI) decreases the rate of oxirane acidolysis. The structure effect of the base on the regioselectivity of the epichlorohydrin acidolysis has been established. It has been shown that the increase of base's nucleophilicity and system's steric hindrances increase the regioselectivity of reaction. The obtained data expand the experimental and theoretical base for studying the mechanism of nucleophilic oxirane ring opening by proton-donating reagents in the presence of bases of various structure. The results provide an opportunity to predict the features of the oxirane ring opening by carboxylic acids of linear and branched structure and the synthesis of new materials based on epoxy compounds. The obtained results are new and were published in the journals included in the Scopus DB.
Bakhalova Ievheniia A.
Bespal'ko Yuliya M.
Sytnyk Nataliia S.
Shpan'ko Ihor V.
Yutilova Kseniia S.
2020-04-02
Updated: 2026-01-03
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