Visible-light promoted catalyst-free imidation of arenes and heteroarenes.

We described herein a catalyst-free visible-light photolytic protocol for the imidation of arenes and heteroarenes. N-Bromosaccharin was identified as a viable and chemoselective nitrogen radical precursor that undergoes controllable homolytic cleavage under ambient light irradiation. The reaction can be applied to a number of arenes and heteroarenes with good chemo- and regioselectivity. Mechanistic studies revealed that radical chain termination by electron transfer-proton transfer (ET-PT) is the leading productive pathway for the reaction.