Tracking SF5 I in the Iodopentafluorosulfanylation of Alkynes
Thi Mo Nguyen1, Claude Y Legault2, Nicolas Blanchard3
1Univ Rouen Normandie, INSA Rouen Normandie Normandie Univ COBRA UMR 6014, INC3M FR 3038, F-76000, Rouen, France.
Abstract:
In the vibrant field of SF5 chemistry, SF5 X reagents (X=F, Cl, Br) are at the heart of current investigations in radical pentafluorosulfanylation reactions. SF5 I is the missing link whose existence has not been reported despite its potential as SF5 donor. This study reports the formal addition of the hitherto unknown SF5 I reagent to alkynes by means of a combination of SF5 Cl/KI/18-crown-6 ether. The exclusive regio- and stereoselective synthesis of unprecedented (E)-1-iodo-2-(pentafluoro-λ6 -sulfanyl) alkenes was achieved. A consensus was reached through computational and mechanistic studies for the realistic formation of SF5 - anion but not SF5 I in solution and the rational involvement of SF5 ⋅ and iodine radicals in the iodo pentafluorosulfanylation reaction.
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