Synthesis of Spirocyclic‐1,2‐Benzisothiazoles by Rh(III)‐Catalyzed [4+1] Annulation of Sulfoximines with Maleimides

Abstract Rh(III)‐catalyzed spiro‐annulation of sulfoximines with maleimides leads to the diastereoselective synthesis of spirocyclic‐1,2‐benzisothiazole heterocycles is disclosed here. This strategy rapidly assembles five‐membered sulfur‐nitrogen‐containing spirocyclic molecules in one‐step. Moreover, the method is scalable and exhibits favourable diastereoselectivity, moderate functional group tolerance, and excellent site‐selectivity.