Difluoroiodomethane: practical synthesis and reaction with alkenes

Difluorocarbene precusors 2, FSO2CF2COF, FSO2CF2CO2H, FSO2CF2CO2Me and XCF2CO2M react with Kl to give HCF2l 1 in high yields; a smooth reaction of 1 with alkenes or alkynes in the presence of Na2S2O4 gives the difluoromethylated adducts in good yields.