New preparation of difluoroiodomethylsulfanylbenzenes and their radical addition to unsaturated compounds initiated by sodium dithionite

Difluoroiodomethylsulfanylbenzene (3a) and 1-chloro-4-difluoroiodomethylsulfanylbenzene (3b) are novel and efficient difluoromethylating reagents via the reaction with unsaturated compounds, such as alkenes, ethynylbenzene, pent-4-en-1-ols, and pent-4-enoic acids initiated by Na2S2O4, to afford the corresponding adducts, tetrahydrofuran derivatives, and γ-butyrolactones containing difluoromethylene group in moderate to good yields.