title: Enantioselective organocatalytic anti-Mannich-type reaction of N-unprotected 3-substituted 2-oxindoles with aromatic N-Ts-aldimines.
abstract: The modified cinchona alkaloid-catalyzed direct Mannich-type reaction of N-unprotected 2-oxindoles with N-Ts-imine was developed to afford anti-3,3-disubstituted 2-oxindoles with vicinal chiral quaternary and tertiary carbon centers in yields up to 90% with excellent diastereoselectivities (anti/syn up to 95:5) and good enantioselectivies (up to 89% ee). A transition model for the anti-diastereo- and enantioselectivity of the reaction was proposed.
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Han
authors.initials: H
authors.lastname: Jia
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Chen