Evidence of a stepwise acyl-transfer reaction mechanism: Nonlinear Hammett plots for reactions of p-nitrophenyl substituted benzoates with hydroxide and p-chlorophenoxide
作者:Ik-Hwan Um、Eun-Kyung Chung、Dong-Sook Kwon
DOI:10.1016/s0040-4039(97)01033-2
日期:1997.7
21∼2.44 to 1.45∼1.52 as the acyl substituent becomes a strong electron withdrawing group (σ >0.6). Such a break in the Hammett plots is suggestive of a change in the reaction mechanism and strong evidence of a stepwise mechanism for the acyl-transfer reaction.
为标题反应得到的哈米特地块表现出断裂,即ρ酰基值从2.21~2.44作为酰基取代基变强吸电子基团(降低至1.45~1.52 σ > 0.6)。哈米特曲线的这种断裂暗示了反应机理的改变,也为酰基转移反应的逐步机理提供了有力的证据。