Catalytic S N Ar Hydroxylation and Alkoxylation of Aryl Fluorides

Nucleophilic aromatic substitution (S N Ar) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron‐deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic S N Ar reactions. The method is applicable to a broad array of electron‐rich and neutral aryl fluorides, which are inert under classical S N Ar conditions. Although the mechanism of S N Ar reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise‐like energy profile. Notably, we isolated a rhodium η 5 ‐cyclohexadienyl complex intermediate with an sp 3 ‐hybridized carbon bearing both a nucleophile and a leaving group.