C-or O-benzylation of 1,3-dicarbonyl compounds is one of the most fundamental methodologies for carbon-carbon or carbon-oxygen bond formation in organic synthesis. Perfluoroalkanosulfonyl fluoride (R f SO 2

O-Acylation of 1,3-dicarbonyl compounds provides enol esters which act as precursors for the synthesis of chiral alcohols, natural products, heterocycles and functional materials. Perfluoroalkanosulfonyl fluoride (R f SO 2 F) is a class of excellent hydroxyl-activating reagent, and has been extensively developed and used in the formation of C-F, CO , C-N and C-S bonds in organic synthesis. In this work one-step O-acylation of 1,3-dicarbonyl compounds (1,3-diketones and β-ketonic esters) with carboxylic acids activated by R f SO 2 F in alkaline media was disclosed, and the corresponding O-acylation products (enol esters) were generated in moderate to good yields. The optimized reaction conditions are as follows: 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU) as base, CH 2 Cl 2 as solvent, n-C 4 F 9 SO 2 F as activating reagent, room temperature for 30 min and the molar ratio of n(1,3-dicarbonyls)∶n(RCOOH)∶n(R f SO 2 F)∶n(DBU) being 1.0∶1.0∶1.0∶4.0. A novel reagent for one-step O-acylation of 1,3-dicarbonyl compounds with carboxylic acids was developed. The application of R f SO 2 F in organic synthesis was further expanded.