Dipartimento di Chimica e Chimica Industriale, via Risorgimento 35, 56126 Pisa, Italy.
J Org Chem. 2009 Nov 20;74(22):8522-30. doi: 10.1021/jo9009408.
The effect of ionic liquids (ILs) on the Menschutkin reaction between N-methylimidazole and benzyl halides has been investigated. Hammett correlations have been used to obtain information on the reaction mechanism of benzyl chlorides in ionic and molecular solvents. The solvent effects on this reaction have been examined using both multiparameter linear solvation energy relationships and theoretical calculations. These latter have been performed using a supermolecular approach, i.e., the IL is represented by an explicit ionic pair, IP. Two possible different reaction pathways have been obtained changing the position of the IL-IP with respect to the reagents. It is hypothesized that inside the IL the Menschutkin reaction of benzyl chloride with N-methylimidazole can follow different reaction pathways by considering the influence of dynamic heterogeneity in ionic media on the time scale of the lifetime of a transition state.
研究了离子液体 (ILs) 对 N-甲基咪唑与苄基卤化物之间的 Menschutkin 反应的影响。使用哈梅特相关关系获得了关于苄基氯在离子和分子溶剂中反应机理的信息。使用多参数线性溶剂化能量关系和理论计算研究了该反应在溶剂中的影响。后者使用超分子方法进行，即离子液体由显式离子对 IP 表示。通过改变 IL-IP 相对于试剂的位置，得到了两种可能的不同反应途径。假设在离子液体中，考虑到离子介质中动态不均匀性对过渡态寿命时间尺度的影响，苄基氯与 N-甲基咪唑的 Menschutkin 反应可以通过不同的反应途径进行。
