Mechanistic Aspects of Oxygen Transfer by gem-Dialkylperoxonium Ions

Article abstract of DOI:10.1021/jo00240a027

Monocyclic gem-dialkylperoxonium ion 2 has been generated from the reaction of 1-bromo-4-hydroperoxy-4-methylpentane (1) with silver tetrafluoroborate or trifluoroacetate, and related bicyclic ion 4 has been formed from the reaction of 5-hydroxyperoxycyclooctene (3) with N-bromosuccinimide.These species have been shown to oxidize efficiently both dialkyl sulfoxides and methyl phenyl sulfide.Reaction with thianthrene 5-oxide afforded X_Nu values of 0.10 for 2 and 0.72 for 4, while competition reactions with (p-XC6H4)2SO (X=Me, H, F, and Cl) yielded Hammett ρ values (versus ?) of -0.83+/-0.11 and -1.77+/-0.58.These results indicate that gem-dialkylperoxonium ion salts,R²O⁺-OH,X^-, are electrophilic oxygen transfer reagents, tunable to some extent by choice of R¹, R², and X, but provide no evidence of deprotonation to the corresponding dioxygen ylide under the conditions studied.