Solvent and substrate isotope effects on the enolization and carbon-acid ionization of isobutyrophenone
作者:J.R. Keeffe、A.J. Kresge
DOI:10.1139/v96-278
日期:1996.12.1
literature information also provide the solvent isotope effect on the enolization equilibrium, KE(H2O)/KE(D2O) = 0.92, and the solvent isotope effect on the ionization of isobutyrophenone as a carbon acid, kaK(H2O)/kaK(D2O) = 5.4, as well as the product of isotopic fractionation factor and medium effect, , for isobutyrophenone enol and the medium effect, Φ = 0.47, for its enolate ion. The isotope effect on
溴清除用于测量异丁酰苯在 H2O 和 D2O 溶液中的酸催化烯醇化速率以及异丁酰苯-α-d 在 D2O 溶液中的速率。结果提供了对烯醇化反应的溶剂同位素效应 kH +/kD + = 0.56 和底物同位素效应 kH/kD = 6.2,这两者都与该过程的普遍接受的机制一致。本结果与文献信息相结合还提供了溶剂同位素对烯醇化平衡的影响,KE(H2O)/KE(D2O) = 0.92,以及溶剂同位素对异丁苯酮作为碳酸的电离作用,kaK(H2O) /kaK(D2O) = 5.4,以及同位素分馏因子和介质效应的乘积,对于异丁酰苯烯醇和介质效应,Φ = 0.47,对于其烯醇化物离子。对 KE 的同位素效应是有史以来第一次确定简单醛或酮的酮 - 烯醇平衡; 其近单位值与基于分馏因子的预期一致...