Substituent Effects. XIX. Solvolysis of 1-Aryl-1-(trifluoromethyl)ethyl Tosylates
作者:Akihisa Murata、Mutsuo Goto、Ryoji Fujiyama、Masaaki Mishima、Mizue Fujio、Yuho Tsuno
DOI:10.1246/bcsj.63.1129
日期:1990.4
solvolysis of 1-aryl-1-(trifluoromethyl)ethyl tosylates were determined in 80% aqueous ethanol for a series of substituents. The Brown ρ+σ+ treatment fails to give a simple linear plot, but all the p-π-donors deviate upward from the meta-correlation line. On the other hand, the Yukawa–Tsuno LArSR Eq. gives a linear correlation over the whole range of substituents, log(k⁄k0)=−6.287(σ°+1.388Δ\barσR+), with
1-芳基-1-(三氟甲基)乙基甲苯磺酸酯的溶剂分解速率在 80% 乙醇水溶液中测定一系列取代基。Brown ρ+σ+ 处理未能给出简单的线性图,但所有 p-π-供体都从元相关线向上偏离。另一方面,Yukawa-Tsuno LArSR Eq。在整个取代基范围内给出线性相关性,log(k⁄k0)=−6.287(σ°+1.388Δ\barσR+),具有出色的精度。α-CF3 对碳正离子中间体的强烈不稳定似乎仅反映在极高的 r 值上,而不反映在取代基效应的 ρ 值上。这与文献中基于简单布朗 σ+ 处理给出的该反应的结论严重冲突。该反应具有极高的共振需求 r=1.4,应该远远超出简单的 Brown σ+ 分析的范围。改变共振需求应该是充分描述关于共轭碳正离子反应的取代基效应的基本要求。