Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis
作者:Wenxin Chen、Zheng Liu、Jiaqi Tian、Jin Li、Jing Ma、Xu Cheng、Guigen Li
DOI:10.1021/jacs.6b06379
日期:2016.9.28
For the first time, 4-alkyl Hantzsch esters were used to construct molecules with all-carbon quaternary centers by visible light-induced photoredox catalysis via transfer alkylation. Up to a 1500 h(-1) turnover frequency was achieved in this reaction. Reactions of 4-alkyl Hantzsch nitriles as tertiary radical donors joined two contiguous all-carbon quaternary centers intermolecularly, and this chemistry
Cobalt‐Catalyzed Wagner–Meerwein Rearrangements with Concomitant Nucleophilic Hydrofluorination
作者:Reece H. Hoogesteger、Nicola Murdoch、David B. Cordes、Craig P. Johnston
DOI:10.1002/anie.202308048
日期:2023.8.28
A cobalt-catalyzed reaction has been developed, which proceeds via hydrogen atom transfer and radical-polar crossover steps, to form a phenonium ion under non-acidic conditions. This cationic intermediate can be regioselectively fluorinated by a tetrafluoroborate anion to give 1,2-aryl migrated products. Evaluation of distinctly substituted phenonium ion intermediates demonstrated the constraints for