RESUMEN
Fluorinated small molecules are commonly used in functional small-molecule chemistry, and N-difluoromethyl (N-CF2H) compounds are particularly intriguing due to their unique and unexplored physiochemical properties. However, despite limited progress, a general methodological approach to the synthesis of N-CF2H compounds remains elusive. Here, guided by computation, we present a simple and practical protocol to access N-CF2H amides and related carbonyl derivatives. The protocol involves a one-pot conversion of thioformamides through desulfurization-fluorination and acylation, providing N-difluoromethylcarbamoyl fluoride building blocks that can be further diversified to a variety of unexplored N-CF2H carbonyl compounds with rich functionality. Additionally, preliminary studies on their properties and stability showcased their potential application in pharmaceuticals and agrochemicals.
RESUMEN
The 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.
RESUMEN
Newly developed sulfonyl chloride-based regioselective chlorothiolation of alkenes has been disclosed; the reaction is compatible with a variety of functional groups and can be scaled up to the gram scale with no loss in yield. The employment of readily available reactants, mild reaction conditions, and high regioselectivity makes this process very practical. Mechanistic studies revealed a possible free radical reaction pathway.
RESUMEN
A newly developed CF3SO2Na-based trifluoromethylation of secondary amines has been disclosed, and the method has been successfully extended to the configuration of perfluoroalkyl amines using RfSO2Na, complementing the established synthesis strategy of trifluoromethyl amines. Advantages of the method include good functional group tolerance, mild conditions, and inexpensive or easy-to-handle materials. Mechanistic probes indicate that the thiocarbonyl fluoride formed in situ is the key intermediate in the reaction.