Kinetic Study on Nucleophilic Substitution Reactions of 4-Nitrophenyl X-Substituted-2-Methylbenzoates with Cyclic Secondary Amines in Acetonitrile: Reaction Mechanism and Failure of Reactivity-Selectivity Principle
作者:Ji-Youn Lee、Min-Young Kim、Ik-Hwan Um
DOI:10.5012/bkcs.2014.35.1.93
日期:2014.1.20
group (EDG) in the benzoyl moiety deviate negatively from the linear line composed of substrates bearing no EDG. In contrast, the Yukawa-Tsuno plots for the same reactions exhibit excellent linear correlations with X = 0.30-0.59 and r = 0.90-1.15, indicating that the nonlinear Hammett plots are caused by stabilization of the substrates possessing an EDG through resonance interactions but are not due
5a-e 的氨解是非线性的,例如,在苯甲酰基部分具有给电子基团 (EDG) 的底物与由不含 EDG 的底物组成的线性线负偏差。相比之下,相同反应的 Yukawa-Tsuno 图表现出良好的线性相关性,X = 0.30-0.59 和 r = 0.90-1.15,表明非线性 Hammett 图是由具有 EDG 的底物通过共振相互作用稳定引起的,但不是由于速率确定步骤(RDS)的变化。Bronsted 型图是线性的,nuc = 0.66-0.82。因此,已建议 5a-e 的氨解通过逐步机制进行,其中离去基团的离开发生在 RDS。5a-e 氨解的 X 和 nuc 值随着底物和胺的反应性增加而增加,