Generation of Carbocations under Photoredox Catalysis: Electrophilic Aromatic Substitution with 1-Fluoroalkylbenzyl Bromides
作者:Cuiwen Kuang、Xin Zhou、Qiqiang Xie、Chuanfa Ni、Yucheng Gu、Jinbo Hu
DOI:10.1021/acs.orglett.0c03258
日期:2020.11.6
to access valuable 1-fluoroalkyl-1,1-biaryl compounds is established under mild conditions. The key to success is the efficient generation of a destabilized benzylic carbocation intermediate via two consecutive single-electron transfer processes by virtue of visible-light photoredox catalysis. This unique activation pattern avoids using strong Lewis acids and high temperatures that are required for
在温和的条件下,建立了芳烃的新型弗里德-克来福特型烷基化反应,以制得有价值的1-氟烷基-1,1-联芳基化合物。成功的关键是借助可见光光氧化还原催化,通过两个连续的单电子转移过程,高效生成不稳定的苄基碳正离子中间体。这种独特的活化方式避免了在传统的Friedel-Crafts反应中生成不稳定的碳正离子所需的强路易斯酸和高温。该协议证明了光灭活催化电子失活的苄基C-Br键杂合形成不稳定碳正离子中间体的第一个例子。