The α-arylation of sterically hindered silyl ketene acetals (SKAs) with sterically hindered aryl bromides occurs efficiently using Pd[P(t-Bu)3]2 as the optimal catalyst and ZnF2 as a promoter. Less sensitive P(t-Bu)3-based catalysts could be also employed but showed a lower activity. The reaction showed a broad scope with regard to both coupling partners, including heteroaryl bromides and cyclic SKAs
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