Treating a derivative of (-)-camphorsulfonimide (CA name: (3aS)-8,8-dimethyl-4,5,6,7- tetrahydro-3H-3a.6-methano-2,1-benzisothiazole 2,2-dioxide) or the isomeric (+)-fenchonesulfonimide with nitronium tetrafluoroborate in acetonitrile does not lead to the expected products of cationic reactions, e.g. of the Ritter reaction for halogenated compounds, but provokes a cleavage of the sulfonimide group with the formation of a ring-opened product containing a sulfonyl fluoride and a nitroimine group. The reaction does occur only in the presence of solid nitronium tetrafluoroborate. but not after prior dissolution of the reagent. An X-ray structure of the product from (1 S)-3-endo-bromocamphorsulfonimide confirms this unusual reaction.
X-ray analysis of an unusual reaction in lysozyme
