Full metadata record
DC Field | Value | Language |
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dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T12:08:28Z | - |
dc.date.available | 2016-08-28T12:08:28Z | - |
dc.date.issued | 2011 | - |
dc.identifier.issn | 1477-0520 | - |
dc.identifier.other | OAK-8127 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/222079 | - |
dc.description.abstract | A kinetic study is reported for hydrolysis of 1-(X-substituted-benzoyl)-4- aminopyridinium ions 2a-i, which were generated in situ from the nucleophilic substitution reaction of 2,4-dinitrophenyl X-substituted-benzoates 1a-i with 4-aminopyridine in 80 mol% H 2O/20 mol% DMSO at 25.0 ± 0.1 °C. The plots of pseudo-first-order rate constants k obsdvs. pyridine concentration are linear with a large positive intercept, indicating that the hydrolysis of 2a-i proceeds through pyridine-catalyzed and uncatalyzed pathways with the rate constant k cat and k o, respectively. The Hammett plots for k cat and k o consist of two intersecting straight lines, which might be taken as evidence for a change in the rate-determining step (RDS). However, it has been proposed that the nonlinear Hammett plots are not due to a change in the RDS but are caused by stabilization of 2a-i in the ground state through a resonance interaction between the π-electron-donor substituent X and the carbonyl functionality. This is because the corresponding Yukawa-Tsuno plots exhibit excellent linear correlations with ρ X = 1.45 and r = 0.76 for k cat while ρ X = 1.39 and r = 0.72 for k o. A possibility that the hydrolysis of 2a-i proceeds through a concerted mechanism has been ruled out on the basis of the large ρ X values. Thus, the reaction has been concluded to proceed through a stepwise mechanism in which the leaving group departs after the RDS since OH - is more basic and a poorer nucleofuge than 4-aminopyridine. © The Royal Society of Chemistry 2011. | - |
dc.language | English | - |
dc.title | Hydrolysis of 1-(X-substituted-benzoyl)-4-aminopyridinium ions: Effect of substituent X on reactivity and reaction mechanism | - |
dc.type | Article | - |
dc.relation.issue | 23 | - |
dc.relation.volume | 9 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.startpage | 8062 | - |
dc.relation.lastpage | 8067 | - |
dc.relation.journaltitle | Organic and Biomolecular Chemistry | - |
dc.identifier.doi | 10.1039/c1ob06137b | - |
dc.identifier.wosid | WOS:000296873900017 | - |
dc.identifier.scopusid | 2-s2.0-81255128921 | - |
dc.author.google | Um I.-H. | - |
dc.author.google | Kim E.-H. | - |
dc.author.google | Kang J.-S. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |