The synthesis of acyl fluorides using the deoxofluorination reaction of carboxylic acids using XtalFluor-E is described. This transformation, assisted by a catalytic amount of NaF, occurs at room temperature in EtOAc, where XtalFluor-E behaves as the activating agent and the fluoride source. A wide range of acyl fluorides were obtained in moderate to excellent yields (36–99%) after a simple filtration on a pad of silica gel. We also demonstrated that sequential deoxofluorination/amidation was possible.

Acyl fluorides are valuable intermediates in organic synthesis. They are increasingly employed in peptide synthesis, in challenging esterification and amidation reactions or in transition-metal-catalyzed transformations. This review summarizes recent advances in their preparation.1 Introduction2 Nucleophilic Fluorination2.1 α-Fluoroamine Reagents2.2 Sulfur-Based Reagents2.3 Metal Catalysts2.4 Phosphorus-Based Reagents2.5 N,N′-Dicyclohexylcarbodiimide/HF·Pyridine2.6 Uranium Hexafluoride2.7 Bromine Trifluoride3 Radical Fluorination4 Conclusion

The room temperature synthesis of difluoromethyl-containing compounds using the deoxofluorination reaction of aromatic aldehydes using XtalFluor-E under highly concentrated conditions is described.