title: Organocatalytic asymmetric Michael addition of unprotected 3-substituted oxindoles to 1,4-naphthoquinone.
abstract: We reported the first example of organocatalytic Michael addition of unprotected 3-prochiral oxindoles 1 to 1,4-naphthoquinone. Quinidine derivative (DHQD)(2)PYR was found to be able to catalyze this reaction in up to 83% ee, with moderate to excellent yields. This method could be used for the synthesis of enantioenriched 3,3-diaryloxindoles, and the catalytic synthesis of which was unprecedented.
authors.affiliation: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai, 200062, P. R. China.
authors.forename: Jin-Sheng
authors.initials: JS
authors.lastname: Yu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.forename: Yun-Lin
authors.initials: YL
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou