Elimination Reactions of (<i>E</i>)-2,4,6-Trinitrobenzaldehyde<i>O</i>-Benzoyloximes Promoted by R<sub>2</sub>NH/R<sub>2</sub>NH<sub>2</sub><sup>+</sup>in 70 mol% MeCN (aq). Effects of the β-Aryl Group and Leaving Group on Nitrile-Forming Transition States
作者:Sang Yong Pyun、Kyu Cheol Paik、Man So Han、Bong Rae Cho
DOI:10.1002/bkcs.10791
日期:2016.6
For eliminations from (E)‐ArCHNOC(O)C6H4X (1, 3) and (E)‐2,4,6‐(NO2)3C6H2CHNOAr′ (2, 3), the change of the β‐aryl group (Ar) from 2,4‐dinitrophenyl (1) to 2,4,6‐trinitrophenyl (3) increased the rate by 270‐fold without appreciable change in the transition state structure. On the other hand, the leaving group (OAr′) variation from benzoate (3) to 4‐nitrophenoxy (2) induced a change in reaction mechanism
(的消除反应ë)-2,4,6-(NO 2)3 c ^ 6 ħ 2 CHNOC(O)C 6 H ^ 4 X(3)由R促进2 NH / R 2 NH 2 +在70摩尔已研究了%MeCN(水溶液)。反应产生消除产物,并表现出二级动力学。β和| βlg | 所有离去群体和基地的价值几乎保持不变。该结果可以通过忽略不计来描述p XY 相互作用系数,p XY =∂β/∂p ķ LG =∂β LG/∂p ķ BH ≈0,这提供了用于(E1cb)了强有力的支持IRR机制。用于从抵销(ë)-ArCHNOC(O)C 6 H ^ 4 X(1,3)和(ë)-2,4,6-(NO 2)3 c ^ 6 ħ 2 CHNOAr'(2,3),β-芳基(Ar)从2,4-二硝基苯基(1)变为2,4,6-三硝基苯基(3)的速率增加了270倍,而过渡态结构却没有明显变化。另一方面,离去基团(OAr')与苯甲酸酯(3)