Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T12:08:27Z | - |
dc.date.available | 2016-08-28T12:08:27Z | - |
dc.date.issued | 2010 | - |
dc.identifier.issn | 0253-2964 | - |
dc.identifier.other | OAK-7446 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/221513 | - |
dc.description.abstract | Pseudo-first-order rate constants (kobsd) have been measured for nucleophilic substitution reactions of 2-pyridyl benzoate 5 with alkali metal ethoxides (EtOM, M = Li, Na, K) in anhydrous ethanol. The plots of k obsd vs. [EtOM]o are curved upwardly but linear in the excess presence of 18-crown-6-ether (18C6) with significant decreased k obsd values in the reaction with EtOK. The kobsd value for the reaction of 5 with a given EtONa concentration decreases steeply upon addition of 15-crown-5-ether (15C5) to the reaction medium up to ca. [15C5]/[EtONa]o = 1, and remains nearly constant thereafter, indicating that M+ ions catalyze the reaction in the absence of the complexing agents. Dissection kobsd into kEtO- and k EtOM, i.e., the second-order rate constants for the reaction with the dissociated EtO. and the ion-paired EtOM, respectively has revealed that ion-paired EtOM is 3.2-4.6 times more reactive than dissociated EtO. It has been concluded that M+ ions increase the electrophilicity of the reaction center through a 6-membered cyclic transition state. This idea has been examined from the corresponding reactions of 4-pyridyl benzoate 6, which cannot form such a 6-membered cyclic transition state. | - |
dc.language | English | - |
dc.title | Effect of alkali metal ions on alkaline ethanolysis of 2-pyridyl and 4-pyridyl benzoates in anhydrous ethanol | - |
dc.type | Article | - |
dc.relation.issue | 10 | - |
dc.relation.volume | 31 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.index | KCI | - |
dc.relation.startpage | 2929 | - |
dc.relation.lastpage | 2933 | - |
dc.relation.journaltitle | Bulletin of the Korean Chemical Society | - |
dc.identifier.doi | 10.5012/bkcs.2010.31.10.2929 | - |
dc.identifier.wosid | WOS:000288766000030 | - |
dc.identifier.scopusid | 2-s2.0-78049389348 | - |
dc.author.google | Lee J.-I. | - |
dc.author.google | Kang J.-S. | - |
dc.author.google | Kim S.-I. | - |
dc.author.google | Um I.-H. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |