Gold‐Catalyzed Fluorination–Hydration: Synthesis of α‐Fluorobenzofuranones from 2‐Alkynylphenol Derivatives

The Au(I) -catalyzed fluorination-hydration of 2-alkynylphenol derivatives in the presence of Selectfluor [1-chloromethyl-4-fluoro-1,4-diazoniabicyclo-[2.2.2]octane bis(tetrafluoroborate)] has been developed. This method provides straightforward access to α-fluorobenzofuranones with the construction of C-O, C=O, and C-F bonds in a single step on the basis of an Au(I) /Au(III) redox catalytic cycle. Several control experiments, including the asymmetric variant of this reaction, were also conducted to gain insight into the reaction mechanism.