ABSTRACT
N-methyl and N-ethyl derivatives of N-(trifluoromethylsulfonyl)-[N'-(trifluoromethylsufonyl)-trifluoromethylsulfoximidoyl] imides 2a,b were prepared by alkylation of bis(trifluoromethylsulfonylimino)trifluoromethanesulfonic acid 1 or its silver salt 1a. It turns out that these imides are strong alkylating agents in spite of the fact that Me (Et) groups are attached to nitrogen atom. The alkylating activity of n-PrI, i-PrI, n-BuI, and n-AmI in the presence of silver salt of bis(trifluoromethylsulfonylimino)trifluoromethanesulfonic acid 1a was investigated.
ABSTRACT
A synthesis of new unsymmetric trifluoromethylsulfonylimino(nonafluoro-n-butyl-sulfonylimino)trifluoromethanesulfonic acid (1b) is reported. During the silylation reactions studies of bis(perfluoroalkylsulfonylimino)trifluoromethanesulfonic acids (1a,b) it was shown that reaction proceeds exclusively on the central oxygen atom to give trimethylsilyl esters. The obtained esters along with several trimethylsilylesters of sulfonic acids have been studied by 29Si-NMR spectroscopy and an attempt to estimate the strength of bis(perfluoroalkylsulfonylimino)trifluoromethanesulfonic acids by the 29Si-NMR chemical shifts of their trimethylsilylesters was made, resulting in the conclusion that these compounds may be cited as the strongest organic Brønsted acids.
