Free radical (phenylsulfonyl)difluoromethylation of alkynes with PhSO2CF2I reagent: stereoselective preparation of PhSO2CF2- and CF2H-substituted alkenes

Stereoselective free radical (phenylsulfonyl)difluoromethylation of terminal alkynes with iododifluoromethyl phenyl sulfone (PhSO2CF2I) has been accomplished by using Et3B/air as an initiator. The obtained PhSO2CF2-substituted vinyl iodides, which can be further subjected to Suzuki coupling and Sonogashira coupling reactions, are useful precursors for the preparation of many structurally diverse PhSO2CF2- and CF2H-substituted alkenes.