Perfluoroalkanesulfonylation of Alkynyl(phenyl)iodonium Tosylates by the Weakly Nucleophilic Sodium Perfluoroalkanesulfinates

Abstract An additive‐ and transition metal‐free perfluoroalkanesulfonylation of alkynyl(phenyl)iodonium tosylates with sodium perfluoroalkanesulfinates (R fn SO 2 Na) is described. The poorly nucleophilic R fn SO 2 Na reacted with alkynyl(phenyl)iodonium salts in dichloromethane at room temperature under a nitrogen atmosphere for 5–60 minutes to afford a variety of acetylenic triflones and alkynyl perfluoroalkyl sulfones in good to quantitative yields. The position of substituents on the phenyl rings of the arylethynyl moiety in the iodonium salts had a big influence on the reaction. The formation of five‐membered cyclic vinyl sulfones suggested that the reaction proceeds via an alkylidene carbene intermediate. Furthermore, successful scaling‐up of the reaction demonstrates the practicality of the new method. Advantages of the method include short reaction times, mild conditions, and the easy access to perfluoroalkanesulfonylation reagents (R fn SO 2 Na). magnified image