Asymmetric Synthesis of Cyclopentane‐Substituted Oxindoles via Organocatalytic Desymmetrization of Cyclopent‐4‐ene‐1,3‐diones

Abstract The highly enantioselective desymmetrization of prochiral cyclopent‐4‐ene‐1,3‐diones has been developed via an organocatalytic Michael reaction. This desymmetrization protocol is efficiently catalyzed by 10 mol% of a bifunctional squaramide, offering a short entry into a series of cyclopentane‐substituted oxindoles bearing two quaternary and one tertiary stereocenters in good yields and high stereoselectivities. magnified image