Palladium-Catalyzed C-H Trifluoroethoxylation of N-Sulfonylbenzamides.

The trifluoroethyl aryl ethers are important motifs in drug molecules. However, a report devoted specifically to the study of transition-metal-catalyzed C-H trifluoroethoxylation has not been reported to date. A protocol of Pd(II)-catalyzed o-C-H trifluoroethoxylation of a broad range of benzoic acid derivatives (i.e., N-sulfonylbenzamides) has been developed. This method is also applied to the formal synthesis of the drug molecule flecainide, wherein the first m-C-H trifluoroethoxylation is also exemplified.