The perfluoroalkylthiolation/decarbonylation reactions of 1,3-dicarbonyl compounds with in situ formed perfluoroalkanesulfenic acids were achieved. Using trifluoromethanesulfonic acid as an additive, a series of α-perfluoroalkylthiolated arylethanones were obtained in moderate to good yields. A possible mechanism was proposed based on the reaction results and control experiments.