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Description
| - The kinetics and mechanism of the acid-catalysed hydrolysis of substituted 4-alkyl-4-methyl-2-aryt-4,5-dihydro-1, 3-oxazol-5-ones to the corresponding 2-alkyl-2-benzoylaminopropanoic acids were studied. The Taft correlation of rate constants of the acid-catalysed hydrolysis with alkyl substitution at the 4-position of the 1,3-oxazol-5-one ring is non-linear. In the Hammett correlation, the value of rho to decreases with increasing steric demand of the alkyl substituent. With the 4-isopropyl and tert-butyl derivatives, rho = -0.63 and -0.32, respectively. The protonated 4-isopropyl and tert-butyl derivatives undergo nucleophilic attack by water at the carbonyl carbon atom at the 5-position of the 1,3-oxazol-5-one ring to the extents of ca 70% and 60%, respectively. Another reaction path consists in nucleophilic attack by water at the 2-position of the 1,3-oxazol-5-one ring. The reaction kinetics of aminolyses of substituted 4-isopropyl-4-methyl-2-phenyl-1,3-oxazol-5(4H)-ones (1a, 1b, 1f) giving substit
- The kinetics and mechanism of the acid-catalysed hydrolysis of substituted 4-alkyl-4-methyl-2-aryt-4,5-dihydro-1, 3-oxazol-5-ones to the corresponding 2-alkyl-2-benzoylaminopropanoic acids were studied. The Taft correlation of rate constants of the acid-catalysed hydrolysis with alkyl substitution at the 4-position of the 1,3-oxazol-5-one ring is non-linear. In the Hammett correlation, the value of rho to decreases with increasing steric demand of the alkyl substituent. With the 4-isopropyl and tert-butyl derivatives, rho = -0.63 and -0.32, respectively. The protonated 4-isopropyl and tert-butyl derivatives undergo nucleophilic attack by water at the carbonyl carbon atom at the 5-position of the 1,3-oxazol-5-one ring to the extents of ca 70% and 60%, respectively. Another reaction path consists in nucleophilic attack by water at the 2-position of the 1,3-oxazol-5-one ring. The reaction kinetics of aminolyses of substituted 4-isopropyl-4-methyl-2-phenyl-1,3-oxazol-5(4H)-ones (1a, 1b, 1f) giving substit (en)
- Byla studována kinetika a mechanismus kysele katalyzované hydrolýzy substituovaných 4-alkyl-4-methyl-2-aryl-4,5-dihydro-1,3-oxazol-5-onů na odpovídající 2-alkyl-2-benzoylaminopropanové kyseliny. Taftova korelace rychlostních konstant kysele katalyzované hydrolýzy v závislosti na alkylsubstituci v poloze 4- 1,3-oxazol-5-onového cyklu je nelineární. U Hammettovy korelace dochází v závislosti na rostoucí sterické náročnosti alkylsubstituentu k snižování hodnoty konstanty. U 4-isopropylderivátů je rho = ?0.63 a u t-butylderivátů ?0.32. Protonované 4-isopropyl deriváty jsou nukleofilně atakovány vodou na karbonylovém uhlíku v poloze 5- 1,3-oxazol-5-onového cyklu cca z 70% a t-butylderiváty cca z 60%. Druhou reakční cestou je nukleofilní atak vody na iminový atom uhlíku v poloze 2- 1,3-oxazol-5-onového cyklu. Kinetika aminolýz 4-isopropyl-4-methyl-2-fenyl-1,3-oxazol-5(4H)-onu, 4-isopropyl-2-(4-metoxyfenyl)-4-methyl-1,3-oxazol-5(4H)-onu a 4-isopropyl-4-methyl-2-(4-nitrofenyl)-1,3-oxazol-5(4H)-onu na N-{1, (cs)
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Title
| - Steric and electronic substituent effects in hydrolysis and aminolysis of 4-alkyl-4-methyl-2-aryl-4,5-dihydro-1,3-oxazol-5-ones
- Sterické a elektronické substituční vlivy při hydrolýze a aminolýze 4-alkyl-4-methyl-2-aryl-4,5-dihydro-1,3-oxazol-5-onů (cs)
- Steric and electronic substituent effects in hydrolysis and aminolysis of 4-alkyl-4-methyl-2-aryl-4,5-dihydro-1,3-oxazol-5-ones (en)
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skos:prefLabel
| - Steric and electronic substituent effects in hydrolysis and aminolysis of 4-alkyl-4-methyl-2-aryl-4,5-dihydro-1,3-oxazol-5-ones
- Sterické a elektronické substituční vlivy při hydrolýze a aminolýze 4-alkyl-4-methyl-2-aryl-4,5-dihydro-1,3-oxazol-5-onů (cs)
- Steric and electronic substituent effects in hydrolysis and aminolysis of 4-alkyl-4-methyl-2-aryl-4,5-dihydro-1,3-oxazol-5-ones (en)
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skos:notation
| - RIV/00216275:25310/05:00003027!RIV08-MSM-25310___
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http://linked.open.../vavai/riv/strany
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http://linked.open...avai/riv/aktivita
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http://linked.open...avai/riv/aktivity
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http://linked.open...iv/cisloPeriodika
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http://linked.open...vai/riv/dodaniDat
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http://linked.open...aciTvurceVysledku
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http://linked.open.../riv/druhVysledku
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http://linked.open...iv/duvernostUdaju
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http://linked.open...titaPredkladatele
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http://linked.open...dnocenehoVysledku
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http://linked.open...ai/riv/idVysledku
| - RIV/00216275:25310/05:00003027
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http://linked.open...riv/jazykVysledku
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http://linked.open.../riv/klicovaSlova
| - hydrolysis; aminolysis; substituent effects; azlactones (en)
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http://linked.open.../riv/klicoveSlovo
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http://linked.open...odStatuVydavatele
| - GB - Spojené království Velké Británie a Severního Irska
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http://linked.open...ontrolniKodProRIV
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http://linked.open...i/riv/nazevZdroje
| - Journal of Physical Organic Chemistry
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http://linked.open...in/vavai/riv/obor
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http://linked.open...ichTvurcuVysledku
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http://linked.open...cetTvurcuVysledku
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http://linked.open...UplatneniVysledku
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http://linked.open...v/svazekPeriodika
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http://linked.open...iv/tvurceVysledku
| - Sedlák, Miloš
- Hanusek, Jiří
- Skála, Pavel
- Keder, Roman
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http://linked.open...n/vavai/riv/zamer
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issn
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number of pages
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http://localhost/t...ganizacniJednotka
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