Preparation, structure, and reactivity of pseudocyclic beta-trifluorosulfonyloxy vinylbenziodoxolone derivatives

Abstract

Vinyl hypervalent iodine(III) compounds are versatile reagents that can be used as efficient synthons for: i) ligand coupling, ii) alpha-elimination reaction, iii) vinylic nucleophilic substitution, and iv) Michael Addition. Numerous preparation methods and reactivity of vinyl hypervalent iodine(III) compounds have been reported. However, the preparation and reactivity of pseudocyclic or cyclic vinyl iodine(III) compounds have not been previously investigated. Our investigation led to the synthesis pseudocyclic beta-trifluorosulfonyloxy vinylbenziodoxolones starting from hydroxybenziodoxolones and alkynes in the presence of trifluoromethanesulfonic acid. Reacting these compounds with sodium azide leads to beta -azido vinylbenziodoxolones of vinylic nucleophilic substitution in which addition-elimination reactions occur and the double bond configuration is retained. The structures of beta -trifluorosulfonyloxy vinylbenziodoxolone and beta -azido vinylbenziodoxolone were supported by single crystal X-ray diffraction.