practical one-pot preparation of carbamoyl fluorides from easily obtained pyridineN-oxide, commercially available secondary amines and synthetically versatile difluorocarbene precursors (Ruppert-Prakash reagent or Chen's reagent) was developed herein, which dexterously resorted to the oxidation of difluorocarbene by external pyridineN-oxide to produce the toxic and gaseous fluorophosgene in situ. Notable