Reactions of Aryl 5-substituted-2-Thiophenecarboxylates Promoted by 4-Z-C<sub>6</sub>H<sub>4</sub>O<sup>−</sup>/4-Z-C<sub>6</sub>H<sub>4</sub>OH in 20 mol % DMSO(aq). Effect of Nucleophile on Acyl-Transfer Reaction
作者:Sang Yong Pyun、Kyu Cheol Paik、Man So Han、Bong Rae Cho
DOI:10.1002/bkcs.10567
日期:2015.12
Nucleophilic substitution reactions of 5‐XC4H2 (S)C(O)OC6H3 ‐2‐Y‐4‐NO2 (1) promoted by 4‐Z‐C6H4O −/4‐Z‐C6H4OH in 20mol % dimethyl sulfoxide (DMSO)(aq) have been studied kinetically. The reactions exhibited second‐order kinetics with βacyl = −2.52 to −2.83, ρ(x) = 2.81–3.16, βnuc = 0.88–0.04 and βlg = −0.94, respectively. The results have been interpreted with an addition–elimination mechanism in which
5-XC的亲核取代反应4 ħ 2(S)C(O)OC 6 H ^ 3 -2-Y-4-NO 2(1 ×4-Z-C促进)6 ħ 4 ø - / 4-Z-已对20 mol%二甲基亚砜(DMSO)(水溶液)中的C 6 H 4 OH进行了动力学研究。该反应显示出第二级动力学与β酰基 = -2.52至-2.83,ρ(X)= 2.81-3.16,β NUC = 0.88-0.04和β LG 分别为-0.94。结果已通过加成消除机制进行了解释,其中亲核攻击发生在速率确定步骤中。与现有数据的比较表明,速率确定步骤从第二步到第一步是通过亲核试剂从R 2 NH / R 2 NH 2 +到4‐Z‐C 6 H 4 O − / 4‐Z的变化而变化的‐C 6 H 4 OH。
Reactions of 2,4‐dinitrophenyl 5‐substituted‐2‐thiophenecarboxylate promoted by <scp>4‐ZC<sub>6</sub>H<sub>4</sub>O<sup>−</sup></scp>/<scp>4‐ZC<sub>6</sub>H<sub>4</sub>OH</scp> in 20 mol% <scp>DMSO</scp>(aq). Effects of leaving group and nucleophile on the acyl transfer reactions
作者:Sang Yong Pyun、Kyu Cheol Paik、Man So Han、Seung Taek Hong、Bong Rae Cho
DOI:10.1002/bkcs.12780
日期:2023.11
The kinetics of nucleophilic substitution reactions involving 2,4-dinitrophenyl 5-substituted-2-thiophenecarboxylate were studied kinetically with 4-Z-C6H4O−/4-Z-C6H4OH, which facilitated the reactions, in 20mol% DMSO(aq). The reactions followed second-order kinetics and exhibited βacyl = −2.34 to −2.92, ρ(Y) = 2.71–3.39, βnuc = 0.74–0.83, and |βlg| = 0.40–0.57. Based on the interpretation of the
使用促进反应的 4-ZC 6 H 4 O − /4-ZC 6 H 4 OH 在 20 mol% DMSO 中对涉及 2,4-二硝基苯基 5-取代-2-噻吩甲酸酯的亲核取代反应动力学进行了动力学研究(阿克)。反应遵循二级动力学,表现出β acyl = -2.34 至 -2.92,ρ (Y) = 2.71–3.39,β nuc = 0.74–0.83,并且 | β lg | = 0.40–0.57。基于对结果的解释,我们得出结论,该反应遵循加成-消除机制,其中第一步是速率决定步骤(rds)。4-ZC 6 H 4 O -促进的反应的过渡态结构几乎保持不变,只是离去基团从4-硝基苯氧基变为2,4-二硝基苯氧基。4-ZC 6 H 4 O -促进反应的机理与R 2 NH促进反应相似,不同之处在于前者以第一步rds进行,后者以rds变化进行。第一步的第二步使用更强的亲核试剂。
Decarboxylative Hydroxylation of Benzoic Acids
作者:Wanqi Su、Peng Xu、Tobias Ritter
DOI:10.1002/anie.202108971
日期:2021.11.2
Herein, the first decarboxylative hydroxylation reaction to synthesize phenols from benzoic acids is reported. The method overcomes the challenges associated with conventional decarboxylation of benzoic acids and can be applied even for the late-stage functionalization.