NH‐Sulfilimine Synthesis Catalyzed by Nonheme Iron(II) Complex

Iron‐catalyzed nitrene transfer reactions have gained significant interest in recent decades. However, the catalytic synthesis of sulfilimines, the aza‐analog of sulfoxides, remains underexplored, and the few examples published only describe protected nitrene transfer reactions. With the rising importance of sulfoximines in medicinal chemistry, sulfilimines are also emerging as valuable targets for drug discovery and bioactive molecule development. Here, an iron‐catalyzed NH‐sulfilimination reaction using a bioinspired iron complex, [Fe(II)MeTPEN](OTf) 2 , in combination with PivONH 3 (OTf) as nonprotected nitrene donor is reported. The reaction operates under atmospheric conditions at room temperature and exhibits broad substrate scope, with yields exceeding 80% for most sulfide compounds. The method demonstrates high selectivity, functional group tolerance, and scalability. Notably, the sulfilimination of penicillin G methyl ester is successfully performed, suggesting potential applications in late‐stage drug functionalization.