Phosphonium SF Salts Derived from Sulfur Hexafluoride as Deoxyfluorination Reagents.

Sulfur based deoxyfluorination reagents are usually derived from the corrosive gas SF. Herein, we report the synthesis and properties of an easily accessible phosphonium salt [(tmg)PF]SF (1) which was obtained from the reaction of sulfur hexafluoride (SF) with tris(tetramethylguanidinyl)phosphine. The performance of this crystalline SF salt as a reagent in deoxyfluorination reactions was investigated together with a second SF salt [(R)PF]SF (2) containing bulky substituents (R=1,3-di-tert-butylimidazolidin-2-ylidenamino). Both reagents proved to be effective for the deoxyfluorination of various functional groups including alcohols, anhydrides, and amides.