Competition between Nucleophilic Substitution of Halogen (S<sub>N</sub>Ar) versus Substitution of Hydrogen (S<sub>N</sub>ArH)-A Mass Spectrometry and Computational Study
作者:Kacper Błaziak、Mieczysław Mąkosza、Witold Danikiewicz
DOI:10.1002/chem.201406542
日期:2015.4.13
ylacetamide carbanions (X=H, F, Cl) has been studied using negative ion electrospray mass spectrometry ((−)ESI‐MS) technique and modelled computationally. It was proven that all three anions form cyclic σH adducts, which undergo elimination of water. In the case of X=F, formation of the σF adduct, leading to SNAr reaction, was a competing process. This is the first proof that also in the gas phase
使用负离子电喷雾质谱((-)ESI-MS)研究了N-(2-X--5-硝基苯基)-N-甲基乙酰胺碳负离子(X = H,F,Cl)的分子内气相反应机理)技术并进行计算建模。据证实,这三个阴离子形成环状σ ^ h加合物,其经历消除水。在X = F,形成σ的情况下˚F加合物,导致至S Ñ的Ar反应,是一个竞争的过程。这是第一个证明,在气相中H形成加合物的过程也比X进行得快。加合物,并且只有当X = F时,这两个过程的速率才具有可比性。实验结果与量子化学计算完全吻合。