Phosphonium SF5 - Salts Derived from Sulfur Hexafluoride as Deoxyfluorination Reagents

Chemistry. 2024 Oct 8;30(56):e202402028. doi: 10.1002/chem.202402028. Epub 2024 Sep 19.

Abstract

Sulfur based deoxyfluorination reagents are usually derived from the corrosive gas SF4. Herein, we report the synthesis and properties of an easily accessible phosphonium salt [(tmg)3PF]+SF5 - (1) which was obtained from the reaction of sulfur hexafluoride (SF6) with tris(tetramethylguanidinyl)phosphine. The performance of this crystalline SF5 - salt as a reagent in deoxyfluorination reactions was investigated together with a second SF5 - salt [(R1)3PF]+SF5 - (2) containing bulky substituents (R1=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.

Keywords: deoxyfluorination; fluorinations; fluorine; phosphorus; sulfur hexafluoride.