Sulfilimines Are Azide Alternatives for Nitrene-Mediated Aromatic C-to-N Transmutation.

C-to-N atom transmutation reactions present the opportunity to conduct nitrogen scans in a direct fashion, but adoption of these methods has been hindered by the requirement for azide precursors, which impose hazards related to toxicity and energetic properties. Herein, we report sulfilimines as alternative, photoactivatable nitrene precursors, which serve as drop-in replacements across three mechanistically distinct, recently reported C-to-N transmutation reactions. Compared to azide-based protocols, sulfilimine-mediated reactions proceed with comparable or superior efficiency, with reduced reaction times and improved scalability. The requisite precursors can be prepared from a variety of functional handles, including those accessible through C-H functionalization, enabling C-to-N replacement on complex scaffolds. These results establish sulfilimines as a practical, azide-free platform for C-to-N skeletal editing and should facilitate the broader implementation of atom transmutation methods in practice.