Full metadata record
DC Field | Value | Language |
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dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T11:08:44Z | - |
dc.date.available | 2016-08-28T11:08:44Z | - |
dc.date.issued | 2001 | - |
dc.identifier.issn | 0022-3263 | - |
dc.identifier.other | OAK-769 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/218830 | - |
dc.description.abstract | Second-order rate constants have been measured spectrophotometrically for the nucleophilic reactions of three substituted phenyl acetates with butane-2,3-dione monoximate (Ox-) as an α-nucleophile and p-chlorophenoxide (ClPhO-) as corresponding normal nucleophile, in MeCN-H2O mixtures of varying compositions at 25.0 ± 0.1 °C. The reactivity of Ox- toward the aryl acetates decreases upon addition of MeCN to the reaction medium up to ca. 30 mol % MeCN, followed by a gradual increase in rate upon further addition of MeCN. A similar result has been obtained for the reaction of ClPhO- with the aryl acetates. However, the decrease in rate is more significant for the less reactive ClPhO- than for the more reactive Ox-. Thus, for all the aryl acetates studied, Ox-exhibits a sizable α-effect (kOx-/kClPhO-) whose magnitude increases as the mol % MeCN in the reaction medium increases. The relative basicities (ΔpKa) of Ox- and ClPhO- have been determined spectrophotometrically using piperazine as a reference base. The ΔpKa values increase on increasing the mol % MeCN in the medium for both Ox- and ClPhO-. The difference in the relative basicities of these nucleophiles (ΔΔpKa) becomes larger with increasing mol % MeCN. The plots of log kOx-/kClPhO- vs ΔΔpKa for the three substrates are linear with near-unit slope, indicating that the difference in the relative basicity of the nucleophiles is largely responsible for the increasing α-effect with medium composition in this system. | - |
dc.language | English | - |
dc.title | Solvent effect on the α-effect for the reactions of aryl acetates with butane-2,3-dione monoximate and p-chlorophenoxide in MeCN-H2O mixtures | - |
dc.type | Article | - |
dc.relation.issue | 14 | - |
dc.relation.volume | 66 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.startpage | 4859 | - |
dc.relation.lastpage | 4864 | - |
dc.relation.journaltitle | Journal of Organic Chemistry | - |
dc.identifier.doi | 10.1021/jo0156114 | - |
dc.identifier.wosid | WOS:000169785500020 | - |
dc.identifier.scopusid | 2-s2.0-0035854316 | - |
dc.author.google | Um I.-H. | - |
dc.author.google | Lee E.-J. | - |
dc.author.google | Buncel E. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |