Enantioselective Synthesis of Spiro[1,3‐indanedione–tetrahydrothiophene]s by Organocatalytic Sulfa‐Michael/Michael Domino Reaction

The organocatalytic asymmetric domino reaction between 2‐arylidene‐1,3‐indanediones and 4‐mercapto‐2‐butenoates for the construction of chiral spiro[indane‐1,3‐dione–tetrahydrothiophene] skeletons was developed. In the presence of a tertiary amine–thiourea organocatalyst, a series of 2‐arylidene‐1,3‐indanediones reacted with tert ‐butyl 4‐mercapto‐2‐butenoate smoothly to furnish chiral spiro heterocycles in good yields (75–99 %) with high enantioselectivities (89–99 %  ee ) and diastereoselectivities (75.4:24.6 to 97.1:2.9  dr ). Notably, functionalized chiral spiro heterocycles were also built in one pot through an aldol condensation/sulfa‐Michael/Michael domino reaction in similarly high yields with high asymmetric induction.