РЕАКЦИОННАЯ СПОСОБНОСТЬ 1 АЛКИЛ 4 (ОКСИМИНОМЕТИЛ)ПИРИДИНИЙ ГАЛОГЕНИДОВ И ГИДРАТИРОВАННЫХ КАРБОНИЛЬНЫХ СОЕДИНЕНИЙ В РЕАКЦИИ РАСЩЕПЛЕНИЯ ПНФА
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| Title |
РЕАКЦИОННАЯ СПОСОБНОСТЬ 1 АЛКИЛ 4 (ОКСИМИНОМЕТИЛ)ПИРИДИНИЙ ГАЛОГЕНИДОВ И ГИДРАТИРОВАННЫХ КАРБОНИЛЬНЫХ СОЕДИНЕНИЙ В РЕАКЦИИ РАСЩЕПЛЕНИЯ ПНФА
REACTIVITY OF 1-ALKYL-1-(HYDROXYIMINOMETHYL)PYRIDINIUM HALIDES AND HYDRATED CARBONYL COMPOUNDS IN THE CLEAVAGE OF PNPA |
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| Creator |
Савсуненко, Александр Олегович
Карпичев, Евгений Адольфович Капитанов, Илья Владимирович |
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| Subject |
4-нитрофенилацетат
перенос ацильной группы оксим хлоральгидрат гидратированные кетоны acyl transfer oximes chloral hydrate hydrated ketones 4-nitrophenyl acetate |
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| Description |
Проведено детальное исследование взаимодействия супернуклеофильного реагента 1-метил-4-(оксиминометил)пиридиний йодида (4-ПАМ) с 4–нитрофенилацетатом (ПНФА). На основании данных pH- и концентрационных зависимостей, а также варьирования соотношения ПНФА:4-ПАМ, предложена кинетическая модель этого процесса, найдены константы скоростей каждой из стадий. Проанализировано влияние стабильных гем-диолов (хлоральгидрата и гидратированного 1-метил-4-(оксиминометил)пиридиний йодида) на скорость реакции.
Oximes are among the most powerful organic supernucleophiles demonstrating high efficiency in the acyl transfers, including cleavage of the toxic organophosphorus compounds. In the reaction of oximolysis of acyl substrates, is of great importance to reach high observed reaction rates as well as to yield an ability of the system to act as a nucleophilic catalyst (turnover) which would provide the efficient decomposition of the large amounts of an acyl substrate. A detailed study of the reaction of supernucleiphilic reagent, 1-methyl-4-(hydroxyiminometyl)pyridinium iodide (4-pam), with 4-nitrophenyl acetate (pnpa) was carried out. Concentration dependences and ph-dependences were investigated. Using the different ratios of pnpa:4-pam, a kinetic model of the overall process was proposed, rate constants for the each stage were found. Effect of the stable gem-diol (chloral hydrate and hydrated 1-methyl-4-(oxyiminomethyl)pyridinium iodide) on the reaction rate was analyzed. Analysis of the reactivity of oxime / chloral hydrate and oxime / hydrated ketone systems demonstrated that observed rate of pnpa cleavage is the sum of the observed reaction rates: oxime interaction with pnpa, and chloral hydrate reaction with pnpa. For the system 4-pam / chloral hydrate / hydrated ketone, observed reaction rate was not differing from that in the absence of ketone. Thus, we can conclude that 4-pam in acetyl group transfer (cleavage of pnpa) acts as a nucleophilic catalyst, and the deacylation step is the rate-determining. Chloral hydrate and 1-methyl-3-acetylpyridinium iodide did not provide increasing deacylation rate. Using of low basicity hydrated carbonyl compounds (e.g. 1-alkyl-3-trifluoroacetyl pyridinium salts) to facilitate deacylation process was proposed. |
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| Date |
2013-04-13T13:33:46Z
2013-04-13T13:33:46Z 2013 |
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| Type |
Article
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| Identifier |
2074-6652
УДК 541.124:541.183:547.288.4 http://ea.donntu.edu.ua/handle/123456789/18470 |
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| Relation |
Наукові праці ДонНТУ;Серія: Хімія і хімічна технологія, 2013. - Вип.2(21). - С.112-118
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| Publisher |
Донецк, ДонНТУ
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