作者:Sergei I. Vdovenko、Igor I. Gerus、Jacek Wójcik
DOI:10.1002/poc.390
日期:2001.8
kinetics of the reaction of β-alkoxyvinyl methyl ketones R1O—CR2CH— COCX3 (1a–e)(a, R1CH3, R2H, XH; b, R1C2H5, R2H, XF; c, R1C2H5, R2H, XCl; d, R1R2CH3, XCl;e, R1R2CH3, XF) with aliphatic amines was studied in various solvents. The details of appropriate enaminoketone (2a–d) formation are discussed in terms of an addition–elimination reaction. It is shown that the limiting step of the reaction is the decomposition
β-烷氧基乙烯基甲基酮R 1 O-CR 2 CH- COCX 3(1a-e)(a,R 1 CH 3,R 2 H,X H; b,R 1 C 2 H 5, R 2 H,X F;c,R 1 C 2 H 5,R 2 H,X Cl;d,R 1 R 2 CH 3,X Cl;e,R 1 R在各种溶剂中研究了具有脂肪族胺的2 CH 3,X F)。适当的烯胺酮(2a–d)形成的细节将通过加成-消除反应进行讨论。结果表明,该反应的限制步骤是两性离子中间体的分解,观察到的二级反应速率常数是溶剂相对介电常数ivity r的函数。在非极性溶剂中胺浓度高时,由于中间分解的催化途径,三级速率系数出现在反应速率方程中。该反应具有较低的ΔH ≠和较高的负ΔS ≠由于形成了高极性的两性离子中间体而产生了较高的值。其寿命主要由COCX 3的吸电子能力决定。版权所有©2001 John Wiley&Sons,Ltd.