Asymmetric Michael Addition Reaction of 3-Substituted Oxindoles to Nitroolefins Catalyzed by a Chiral Alkyl-Substituted Thiourea Catalyst

A simple alkylthiourea was found to be an effective catalyst for the Michael addition reaction of 3-substituted oxindole to nitroolefins. A number of 3,3'-substituted oxindole derivatives, which have two vicinal quaternary-tertiary chiral centers were synthesized with up to 99% yields 19:1 dr and 98% ee.