Synthesis and Structure of Hypervalent Diacetoxybromobenzene and Aziridination of Olefins with Imino-λ³-bromane Generated in Situ under Metal-Free Conditions

Ligand exchange of p-CF₃C₆H₄BrF₂ with acetoxy groups using AcOH and Ac₂O affords (diacetoxybromo)benzene in a high yield, which undergoes aziridination of alkenes in the presence of TfNH₂ and sulfamate esters in one pot under mild conditions. The aziridination with TfNH₂ proceeds stereospecifically with retention of stereochemistry of olefins at room temperature using limiting amounts of olefins under transition-metal-free conditions. The one-pot aziridination procedure using sulfamate esters can be applied to the intramolecular versions.