制备了一系列间氟取代的二苯甲基氯化物、溴化物、甲磺酸盐和甲苯磺酸盐 1-X 至 5-X,并在各种溶剂中进行溶剂分解反应。发现观察到的一阶速率常数 ks (25 °C) 遵循相关方程 log ks (25 °C) = sf (N f + E f ),这使我们能够确定这些不稳定的电离参数 E f二苯甲基阳离子和一系列离去基团/溶剂组合的离核参数 N f , sf 。
Chiral N-Heterocyclic Carbene−Copper(I)-Catalyzed Asymmetric Allylic Arylation of Aliphatic Allylic Bromides: Steric and Electronic Effects on γ-Selectivity
作者:Khalid B. Selim、Hirotsugu Nakanishi、Yasumasa Matsumoto、Yasutomo Yamamoto、Ken-ichi Yamada、Kiyoshi Tomioka
DOI:10.1021/jo102386s
日期:2011.3.4
sterically tuned to improve γ-selectivity in copper(I)-catalyzed asymmetric allylic arylation of aliphatic allylic bromides with several aryl Grignardreagents. High γ-selectivity was realized when either the aryl group of the Grignardreagent or the aryl group on the N-substituent of the carbene ligand was electron-deficient or when either the carbene ligand or allylic bromide was bulky. The results indicated
Ion-Pairing of Phosphonium Salts in Solution: CH⋅⋅⋅Halogen and CH⋅⋅⋅π Hydrogen Bonds
作者:Johannes Ammer、Christoph Nolte、Konstantin Karaghiosoff、Sebastian Thallmair、Peter Mayer、Regina de Vivie-Riedle、Herbert Mayr
DOI:10.1002/chem.201204561
日期:2013.10.18
concentration dependence of the 1H NMR chemical shifts allowed us to determine the dissociation constants of the phosphonium salts in CD2Cl2 solution. The cation–anion interactions increase with the acidity of the C(α)H protons and the basicity of the anion. The existence of CH⋅⋅⋅X− hydrogen bonds between the cations and anions is confirmed by quantumchemical calculations of the ion pair structures, as well
Kinetics of the Solvolyses of Fluoro-Substituted Benzhydryl Derivatives: Reference Electrofuges for the Development of a Comprehensive Nucleofugality Scale
作者:Christoph Nolte、Herbert Mayr
DOI:10.1002/ejoc.200901400
日期:2010.3
A series of m-fluoro-substituted benzhydrylchlorides, bromides, mesylates, and tosylates 1-X to 5-X were prepared and subjected to solvolysis reactions in various solvents. The observed first-order rate constants k s (25 °C) were found to follow the correlation equation log k s (25 °C) = s f (N f + E f ), which allowed us to determine the electrofugality parameters E f for these destabilized benzhydrylium
制备了一系列间氟取代的二苯甲基氯化物、溴化物、甲磺酸盐和甲苯磺酸盐 1-X 至 5-X,并在各种溶剂中进行溶剂分解反应。发现观察到的一阶速率常数 ks (25 °C) 遵循相关方程 log ks (25 °C) = sf (N f + E f ),这使我们能够确定这些不稳定的电离参数 E f二苯甲基阳离子和一系列离去基团/溶剂组合的离核参数 N f , sf 。