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