Accessing Enantiopure Endocyclic Sulfoximines Through Catalytic Cycloisomerization of Oxygenated Propargyl-Sulfinamides

In this study, a novel strategy to access endocyclic sulfoximines in an enantiopure form is reported. The approach is based on a silver nitratecatalyzed cyclo-isomerization reaction of oxygenated propargylic sulfinamides and provides efficiently 5-membered endocyclic sulfoximines (isothiazole 1-oxide). These new heterocyclic scaffolds can be isolated or directly converted into cyclic sulfinamides via Lewis acid-mediated sulfur dealkylation reactions.