Anionic Fries Rearrangement of <i>ortho</i>-Iodophenyl Carboxylate Initiated by Potassium Hydride

In order to generate an aryl anion, metal-halogen exchanges initiated by alkyllithium, lithium amide, or Grignard reagent are frequently employed. However, carbonyl groups are not compatible with these reagents. Herein, we demonstrate that aryl iodide can undergo direct K-I exchange with KH to produce an aryl anion species. Due to the toleration of this process with ester and ketone groups, it is suitable for the anionic Fries rearrangement reaction of <i>ortho</i>-iodophenyl carboxylates to provide <i>ortho</i>-acylphenol or <i>ortho</i>-acylaniline products, which has long been a great challenge for traditional methods. Moreover, our protocol can be used for cascade reactions to prepare xanthone and acridone. Notably, although K-I exchange is the major reaction pathway of our process, it is accompanied by hydrodehalogenation (Pierre's process) as a side reaction, which has been validated by the identification of phenol in the final reaction mixture.