We tentatively propose a plausible mechanism for this transformation (Scheme 5). Initially, hydroxylamine-Osulfonic acid undergoes neutralization with base, resulting in the formation of the hydroxylamine-O-sulfonic acid anion (Int I), which easily forms a cluster with HFIP, leading to Int II, stabilized by multiple hydrogen bonds. 25 Subsequently, the N-O bond cleavage assisted by hydrogen bonding to form the electrophilically active Int III, 26 then undergoes a concerted addition with an alkene to form the intermediate Int IV. Finally, the aziridine product is released.