Copper(II)-Catalyzed Radical-Type Selenium(II)–Nitrogen Exchange Chemistry between Benzoselenazolones and Hydrazines

The first radical-type selenium(II)-nitrogen exchange (SeNEx) chemistry was successfully developed, enabling rapid synthesis of diaryl selenides in moderate to excellent yields (46 examples, 21-89%). This chemistry brings arylhydrazines into the SeNEx platform and features mild and robust conditions, scalability, air and water tolerance, broad substrate scope, and good atomic economy, with N₂ and H₂O as the only waste. Furthermore, it tolerates a broad scope of transformable handles such as -OH, -NHBoc, nitro, phenol, ester, amide, sulfonamide, and N-unprotected heterocycles. The results of a mechanistic study support the radical pathway of this reaction. The utilization of this chemistry has been demonstrated by the further -OH- and -NHBoc-based elaboration, highlighting the great potential of this SeNEx chemistry in the synthesis of advanced selenide compounds with drug-like properties.