Perfluorooxosulfate Salts as SOF₄-Gas-Free Precursors to Multidimensional SuFEx Electrophiles

Sulfur(VI) Fluoride Exchange (SuFEx) chemistry stands as a well-established method for swiftly constructing complex molecules in a modular fashion. An especially promising segment of this toolbox is reserved for multidimensional SuFEx hubs: three or more substituents pluggable into a singular S^VI centre to make 'beyond-linear' clicked constructions. Sulfurimidoyl difluorides (RNSOF₂) stand out as the prime example of this, however their preparation from the scarcely available thionyl tetrafluoride (SOF₄) limits this chemistry to only a few laboratories with access to this gas. In this work, we identify silver pentafluorooxosulfate (AgOSF₅) as a viable SuFEx hub with reactivity equal to SOF₄. The AgF₂-mediated oxidation of SOCl₂ gives rise to the hexacoordinate AgOSF₅ adduct, which in contact with primary amines produces the sulfurimidoyl fluorides in high yields. In addition, we have found this workflow to be fully extendable to the trifluoromethyl homologue, AgOSF₄CF₃, and we propose the use of AgOSF₄X salts as a general route to azasulfur SuFEx electrophiles from commercial starting materials.