Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T12:08:03Z | - |
dc.date.available | 2016-08-28T12:08:03Z | - |
dc.date.issued | 2012 | - |
dc.identifier.issn | 0253-2964 | - |
dc.identifier.other | OAK-8559 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/222445 | - |
dc.description.abstract | A kinetic study is reported on nucleophilic displacement reactions of benzyl 2-pyridyl carbonate 6 with alkalimetal ethoxides, EtOM (M = Li, Na, and K), in anhydrous ethanol at 25.0 ± 0.1 oC. The plots of pseudo-firstorder rate constant kobsd vs. [EtOM] curve upward, a typical phenomenon reported previously for alkaline ethanolysis of esters in which alkali-metal ions behave as a Lewis-acid catalyst. The kobsd value for the reaction of 6 with a fixed EtOK concentration decreases rapidly upon addition of 18-crown-6-ether (18C6), a complexing agent for K+ ion up to [18C6]/[EtOK] = 1.0 and then remains constant thereafter, indicating that the catalytic effect exerted by K+ ion disappears in the presence of excess 18C6. The reactivity of EtOM towards 6 increases in the order EtO- < EtOLi < EtONa < EtOK, which is contrasting to the reactivity order reported for the corresponding reactions of 2-pyridyl benzoate 4, i.e., EtO- < EtOK < EtONa < EtOLi. Besides, 6 is 1.7 and 3.5 times more reactive than 4 towards dissociated EtO- and ion-paired EtOK, respectively. The reactivity difference and the contrasting metal-ion selectivity are discussed in terms of electronic effects and transition-state structures. | - |
dc.language | English | - |
dc.title | Alkali-metal ion catalysis in alkaline ethanolysis of 2-pyridyl benzoate and benzyl 2-pyridyl carbonate: Effect of modification of nonleaving group from benzoyl to benzyloxycarbonyl | - |
dc.type | Article | - |
dc.relation.issue | 2 | - |
dc.relation.volume | 33 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.index | KCI | - |
dc.relation.startpage | 519 | - |
dc.relation.lastpage | 523 | - |
dc.relation.journaltitle | Bulletin of the Korean Chemical Society | - |
dc.identifier.wosid | WOS:000301330900030 | - |
dc.identifier.scopusid | 2-s2.0-84863115561 | - |
dc.author.google | Um I.-H. | - |
dc.author.google | Kang J.-S. | - |
dc.author.google | Kim C.W. | - |
dc.author.google | Lee J.-I. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |