Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T12:08:53Z | - |
dc.date.available | 2016-08-28T12:08:53Z | - |
dc.date.issued | 2011 | - |
dc.identifier.issn | 0253-2964 | - |
dc.identifier.other | OAK-7730 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/221744 | - |
dc.description.abstract | A kinetic study is reported on nucleophilic substitution reactions of 4-nitrophenyl nicotinate 5 and isonicotinate 6 with alkali metal ethoxide EtOM (M = K, Na, and Li) in anhydrous ethanol at 25.0 ± 0.1 °C. Plots of pseudofirst- order rate constant k obsd vs. EtOM concentration exhibit upward curvature for the reactions of 5 and 6 with EtOK and EtONa but are almost linear for those with EtOLi. Dissection of k obsd into k EtO - and k EtOM (i.e., the second-order rate constant for the reaction with dissociated EtO - and ion-paired EtOM, respectively) has shown that k EtOK ≥ k EtONa > k EtO - but k EtOLi < k EtO -. It has been concluded that K + and Na + ions catalyze the reactions by increasing the electrophilicity of the carbonyl carbon atom through formation of a 4- embered cyclic transition state TS 3 or TS 4. However, M + ion catalysis has been found to be much less significant for the reactions of 5 and 6 than for the corresponding reactions of 4-nitrophenyl picolinate 4, which was reported to proceed through a 5-membered cyclic transition state TS 2. Although 5 and 6 are significantly more reactive than 4-nitrophenyl benzoate 3, the reactions of 5 and 6 result in smaller k EtOK/k EtO - ratios than those of 3. The electron-withdrawing ability of the nitrogen atom in the acyl moiety of 5 and 6 has been suggested to be responsible for the increase in reactivity and the decrease in the k EtOK/k EtO - ratio. | - |
dc.language | English | - |
dc.title | Metal ion catalysis and inhibition in nucleophilic substitution reactions of 4-nitrophenyl nicotinate and isonicotinate with alkali metal ethoxides in anhydrous ethanol | - |
dc.type | Article | - |
dc.relation.issue | 6 | - |
dc.relation.volume | 32 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.index | KCI | - |
dc.relation.startpage | 1951 | - |
dc.relation.lastpage | 1956 | - |
dc.relation.journaltitle | Bulletin of the Korean Chemical Society | - |
dc.identifier.doi | 10.5012/bkcs.2011.32.6.1951 | - |
dc.identifier.wosid | WOS:000292117700021 | - |
dc.identifier.scopusid | 2-s2.0-79959392872 | - |
dc.author.google | Choi S.-Y. | - |
dc.author.google | Hong Y.-J. | - |
dc.author.google | Um I.-H. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |