Direct synthesis of N-trifluoromethyl amides via photocatalytic trifluoromethylamidation.

Abstract

N-CF₃ amides are promising targets for pharmaceutical and agrochemistry. Unfortunately, there is a defluorination problem of N-CF₃ amine starting materials when using common amide bond formation method. Recently, elegant alternative approaches emerged. However, none have used the well known amidyl radical chemistry to directly prepare N-CF₃ amides. We describe here a convenient preparation of N-(N-CF₃ imidoyloxy) pyridinium salts and their applications as efficient trifluoromethylamidyl radical precursors in photocatalytic trifluoromethylamidations of (hetero)arenes, alkenes, alkynes, silylenol ethers, and isocyanides. The rapid construction of diverse N-CF₃ amides, particularly the synthesis of cyclic N-CF₃ amides, demonstrates the uniqueness and flexibility of the method. This method is expected to provide a platform for directly synthesizing N-CF₃ amides and to inspire the discovery of more redox molecular systems that can handle challenging trifluoromethylamidations.