Mechanistic Studies on the Generation and Properties of Superelectrophilic Singlet Carbenes from Bis(perfluoroalkanesulfonyl)bromonium Ylides

Pyrolysis of bis­(perfluoroalkanesulfonyl)­bromonium ylides in various olefins results in highly stereospecific formation of cyclopropanes via unimolecular decomposition. Product analysis, kinetic study, substituent effects, and theoretical study revealed the generation of singlet bis­(perfluoroalkanesulfonyl)­carbenes stabilized by intramolecular coordination of sulfonyl oxygen