Computational Insights into the Reactivity Difference between Hypervalent Bromine(III) and Hypervalent Iodine(III) Reagent in the C−H Amination and Alkene Aziridination

Abstract

We present herein a computational exploration into the mechanism and origin of the reactivity difference between N‐triflylimino‐λ3‐iodane and N‐triflylimino‐λ3‐bromane in the C−H amination and alkene aziridination. Our calculations revealed that the preferred mechanism for C−H amination involves the generation of free nitrene intermediate, while the alkene aziridination proceeds via a concerted reaction mechanism. The superior reactivity of N‐triflylimino‐λ3‐bromane over N‐triflylimino‐λ3‐iodane could be mainly ascribed to better nucleofugality of the bromanyl moiety, which can be characterized by the strength of I−N and Br−N bond. The effect of solvent polarity on the reactivity of N‐triflylimino‐λ3‐bromane as a nitrene precursor will be discussed.magnified image