Solvolyses of isobutyl chloroformate (4) in 43 binary solvent mixtures including highly aqueous media, water, $D_2O$, $CH_3OD$, 2,2,2-trifluoroethanol (TFE) as well as aqueous 1,1,1,3,3,3-hexafluoro-isopropanol (HFIP) solvents were performed at $45^\circ}C$, in order to further investigate the recent results of D'Souza, M. $J^1$. et al.; solvolyses of 4 are found to be consistent with the proposed mechanism ($Ad_E$). The variety of solvent systems was extended to comprise highly ionizing power solvent media ($Y_Cl}$ > 2.7 excepted for aqueous fluorinated solvents and pure TFE solvent) to investigate whether a mechanistic change occurs as solvent compositions are varied. However, in case of 18-solvent ranges having aqueous fluorinated solvent systems (TFE-$H_2O$ and HFIP-$H_2O$) and/or having $Y_Cl}$ > 2.7 solvent systems, the solvent effect on reactivity for those of 4 are evaluated by the multiple regression analysis as competition with $S_N2$ - type mechanism. And in pure TFE and 97 w/w % HFIP solvents with high $Y_Cl}$ and weak $N_T$, these solvolyses are understood as reactions which proceed through an ionization ($S_N1$) pathway.
氯甲酸异丁酯(4)在 43 种二元溶剂混合物(包括高
水性介质、
水、
$D_2O$、
$CH_3OD$、
2,2,2-三氟乙醇(
TFE)以及
水性 1、1,1,3,3,3-
六氟异丙醇 (HFIP) 溶剂在
$45^\circ}C$ 下进行,以进一步研究 D'Souza, M. 最近的研究成果。<等人;发现 4 的溶解度与提出的机理 (
$Ad_E$) 一致。溶剂系统的种类扩大到包括高电离力溶剂介质(
$Y_Cl}$ > 2.7,含
氟水溶液和纯
TFE 溶剂除外),以研究当溶剂成分变化时是否会发生机理变化。然而,对于 18 种溶剂范围中的含
氟水性溶剂体系(
TFE-
$H_2O$ 和 HFIP-
$H_2O$)和/或
$Y_Cl}$ > 2.7 的溶剂体系,通过多元回归分析评估了溶剂对 4 类反应活性的影响,即与
$S_N2$ 型机理竞争。在高
$Y_Cl}$ 和弱
$N_T$ 的纯
TFE 和 97 w/w % HFIP 溶剂中,这些溶解反应被理解为通过电离(
$S_N1$)途径进行的反应。