Isotope Effect Studies on Elimination Reactions. XI. The Nature of the Transition State for the E2 Reaction of 2-Phenylethyldimethylanilinium Salts Containing Substituents in the Aniline Ring with Sodium Ethoxide in Ethanol
作者:Peter Schmid、Arthur Newcombe Bourns
DOI:10.1139/v75-506
日期:1975.12.1
Kinetic isotope effects have been determined for the E2 reactions of a series of 2-phenylethyldimethylanilinium salts containing substituents in the aniline ring with sodium ethoxide in ethanol at 40 °C. The nitrogen isotope effect, (k14/k15−1)100, is not very sensitive to substituent changes but appears to increase slightly with increasing electron-withdrawing ability of the substituents, i.e., 1
动力学同位素效应已经确定了一系列 2-苯基乙基二甲基苯胺盐在苯胺环中含有取代基与乙醇钠在 40 °C 乙醇中的 E2 反应。氮同位素效应 (k14/k15−1)100 对取代基变化不是很敏感,但似乎随着取代基吸电子能力的增加而略微增加,即 1.19 ± 0.07、1.13 ± 0.06、1.12 ± 0.08, p-OCH3、p-CH3、pH、p-Cl 和 m-CF3 分别为 1.30 ± 0.07 和 1.32 ± 0.06。氢-氘同位素效应通过未取代化合物区域的最小值,并随着取代基给电子和吸电子能力的增加而增加,即 kH/kD = 4.70 ± 0.06, 4.61 ± 0.04, p-OCH3、p-CH3、4.51 ± 0.04、4.53 ± 0.09、5.00 ± 0.07 和 5.39 ± 0.07 分别为 pH、p-Cl、m-CF3 和 p-CF3。结果根据最近对反应中结构变化影响的理论处理进行了讨论