Oxidation of Difluorocarbene by Pyridine N‐Oxide and Ensuing Access to Carbamoyl Fluorides†

Abstract

Comprehensive SummaryA practical one‐pot preparation of carbamoyl fluorides from easily obtained pyridine N‐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 pyridine N‐oxide to produce the toxic and gaseous fluorophosgene in situ. Notable features of this method include nice functionality tolerance, late‐stage modification of drug molecules and the recovery and recycle of quinoline.