General Access to N−CF3 Secondary Amines and Their Transformation to N−CF3 Sulfonamides

Abstract

AbstractThe synthesis of N−CF3 compounds through fluorination or trifluoromethylation of N‐containing compounds has been extensively investigated. However, general access to N−CF3 compounds simply from N−CF3 secondary amines is hampered by the challenging preparation and instability of these amines, as well as a much lower reactivity due to the strong electron‐withdrawing nature and steric bulk of the trifluoromethyl moiety. Herein, we report a general and highly efficient synthesis of N−CF3 secondary amines with excellent isolated yields via the addition of the in situ generated difluoromethyl imine (R−N=CF2) intermediates with hydrogen fluoride, which is mildly produced by triethylsilane and silver fluoride. N−CF3 sulfonamides, highly desirable but scarce at present, are easily accessible from these valuable building blocks through an unprecedented route. This study will bring new vitality to the synthesis of N−CF3 compounds.