Undirected ruthenium-catalyzed C-H activation using arylsulfonium salts: direct arylation without ruthenacycle...

Ruthenium-catalyzed C-H activation has surfaced as a transformative platform in molecular sciences. Despite major progress, all ruthenium-catalyzed arylations require the formation of a ruthenacycle. In sharp contrast, we herein report on ruthenium-catalyzed C-H arylation with arylsulfonium salts through a non-cycloruthenated intermediate, which allowed the late-stage incorporation of polyfluoroarenes into natural products and pharmaceuticals in the absence of directing groups. Employing a tBu-substituted dibenzothiophenium salt, we realized polyfluoroarylation for a wide range of functionalized arenes. Detailed experimental and computational studies provided strong support for the C-H arylation to proceed without any metalacyclic intermediate. A data science approach further elucidated the key molecular features governing the reactivity of arylsulfonium salts.