Synthesis of 2H‐Azirines by Iridium‐Catalyzed Decarboxylative Ring Contraction of Isoxazol‐5(4H)‐ones

Abstract A phosphine‐free iridium‐catalyzed reaction of isoxazol‐5(4 H )‐ones (isoxazolones) has been developed, and affords 2 H ‐azirines through decarboxylation and ring contraction. This method provides an efficient and environmentally benign protocol which could replace the conventional approaches used to synthesize 2 H ‐azirines.