Synthesis And Characterization Of Toluenesulfonyl(Perfluorobutanesulfonyl)Imide And Its Derivatives

Organic acids are consisting of small organic molecules, and act an important role in organic synthesis. comparing with the usual organic-metal complexes, it has some prominent advantages, such as cheapness, easy to get, good stability, easy operation and so on. organic acid catalysts are obtaining more and more attention in research and industrial areas.Using 4-methyl-benzenesulfonyl chloride, 4-methyl-3-nitrobenzenesulfonyl chloride, 4-methyl-3-trifluoromethylbenzenesulfonyl chloride as starting materials, a series of sulfonimides with a benzene ring and perfluorobutyl function group were synthesized, through sulfonyl, ionic exchange-reaction and so on.Toluenesulfonyl(perfluorobutanesulfonyl)imide, 4-methyl-3-nitrophenylsulfonyl (perfluorobutanesulfonyl)imide and 4-methyl-3-trifluoromethanephenylsulfonyl(per- fluorobutanesulfonyl)imide were characterized by IR, 1H NMR, 19F NMR, MS and Titration. The results are the same as theoretical supposition.The acid strength was measured through Hammett indicator method respectively. The results showed that the strength of sulfonimide experiences a major change while changing substituents on the phenyl ring. Especially when the meso-positions of the sulfonylimide group on the phenyl ring are some strong electron-withdrawing groups such as nitro, trifluoromethyl, the strength of sulfonimides acid strength basically reaches the standard of super-acid. The acid strengths of toluenesulfonyl(perfluoro- butanesulfonyl)imide, 4-methyl-3-nitrophenylsulfonyl(perfluorobutanesulfonyl)imide, 4-methyl-3-trifluoromethanephenylsulfonyl(perfluorobutanesulfonyl)imide were -8.2, -11.35, -11.35 respectively. This result maybe provide a useful exploration for the design and synthesis of different Br?nsted sulfonamides in the further research.