Studies on sulfinato‐dehalogenation: XII. Sodium dithionite‐initiated addition of N , N ‐diethyliododifluoroacetamide to multiple bonds

N , N ‐deithyl‐iododifluoroacetamide 1 reacted with alkenes, alkynes in aqueous acetonitrile solutions of sodium dithionite and sodium hydrogen carbonate at room temperature to give the corresponding adducts, thus constituting a new method for introducing the CF 2 group into organic molecules. Compound 1 reacted with conjugated olefins 2b, c to afford the iodine‐free adducts 7b, c. The adducts 3d—f, from addition of 1 to alkenes 2d—f, could be converted into α,α‐difluoro‐γ‐lactones 5d—f by treatment with silica gel. Compound 1 reacted with ethyl vinyl ether 2i to give aldehyde 8, and perfluoroalkyl or polyfluoroalkyl iodides reacted similarly. A radical mechanism was proposed for the addition reaction. Under the same condition, N , N ‐diethyl‐bromodifluoroacetamide produced only the corresponding sulfinate Et 2 NC(O)CF 2 SO 2 Na.