Making the SF 5 Group More Accessible: A Gas-Reagent-Free Approach to Aryl Tetrafluoro-λ 6 -sulfanyl Chlorides.

Modern pentafluorosulfanyl (SF5) chemistry has an Achilles heel: synthetic accessibility. Herein, we present the first approach to aryl-SF4Cl compounds (key intermediates in state-of-the-art aryl-SF5 synthesis) that overcomes the reliance on hazardous fluorinating reagents and/or gas reagents (e.g. Cl-2) by employing easy-to-handle trichloroisocyanuric acid, potassium fluoride, and catalytic amounts of acid. These simple, mild conditions allow direct access to aryl-SF4Cl intermediates that either have not been or cannot be demonstrated using previous methods. Furthermore, the same approach provides access to aryl-SF3 and aryl-SeF3 compounds, which extend the applications of this chemistry beyond arene SF5-functionalization, and demonstrate its ability to address a more general oxidative fluorination problem.