Directing-Group-Free Arene C(sp²)-H Amination Using Bulky Aminium Radicals and DFT Analysis of Regioselectivity

A hydroxylamine-derived electrophilicaminating reagentproducesa transient and bulky aminium radical intermediate upon insitu activation by either TMSOTf or TFA and a subsequentelectron transfer from an iron(II) catalyst. Density functional theorycalculations were used to examine the regioselectivity of arene C-Hamination reactions on diversely substituted arenes. The calculationssuggest a simple charge-controlled regioselectivity model that enablesprediction of the major C(sp(2))-H amination product.