Sulfonation trifluoromethylsulfonation

As an example of esters of aliphatic sulfonic acids trifluoromethylsulfonic imidazo-lide has been treated with various phenols to give phenyl sulfonic esters [U1... 

A reaction which is related to hydroxy-de-diazoniations is the formation of aryl trifluoromethylsulfonic esters (aryl triflates, ArOSC CFs) which became widely used reagents because of their leaving-group properties. The classical method of synthesis by esterification of phenols with trifluoromethane-sulfonic anhydride or -sulfonyl halide is, however, not applicable for the preparation of aryl triflates bearing a (free)... 

Gais studied the rate of inversion of the lithiated sulfones 244 and 245, and found that they were remarkably similar about 40 kJ mol-1 at 215 K.117 Given the difference in structure, these results suggest strongly that, for sulfones, formation of an ion pair is not the rate-limiting step of the racemisation. The trifluoromethylsulfone 246 has an even higher barrier to racemisation 66 kJ mol-1 at 333 K.117... 

Nitrophenyl) ethyl] sulfonate, 275 2-Trifluoromethylsulfonate, 275 4-Monomethoxytritylsulfenate, 275 Alkyl 2,4-Dinitrophenylsulfenate, 277 2,2,5,5-Tetramethylpyrrolidin-3-one-l-sulfinate, 278 Borate, 278... 

The activity of Nafion as a catalyst has been increased by applying it on silica by the sol-gel method using tetramethoxysilane20 or tetraethoxysilane and dimethyl-diethoxysilane.21 This increased its activity as a solid acid catalyst up to 100 times that of bulk Nafion. It performed better than Nafion on carbon in the dimerization of a methylstyrene. It was a much better catalyst (seven times on a weight basis) than Amberlyst 15, a typical sulfonic acid ion-exchange resin. It was more active in the benzyla-tion of benzene (6.6) than trifluoromethylsulfonic acid, a reaction in which Amberlyst 15 and p-toluenesulfonic acid... 

Bis(4-tert-butylphenyl)iodonium triflate XIII is decomposed by UV lighf to produce p-t-butylalkylphenylene, p-t-butylphenylene iodide, and trifluoro-methyl sulfonic acid. Sulfonium PAG is decomposed by UV light as shown in Figure 2.31. Triphenylsulfonium trifluoromethylsulfonate XVIII is decomposed by UV light to produce alkylbenzene, diphenylsulfide, and trifluoro-methyl sulfonic acid. 

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