作者:Songsong Guo、Pei Dong、Yushuang Chen、Xiaoming Feng、Xiaohua Liu
DOI:10.1002/anie.201810679
日期:2018.12.17
copper(I) catalyst for the asymmetric azide‐alkynecycloaddition/[2+2] cascade reaction. Optically active spiroazetidinimine oxindoles were constructed by trapping the ketenimine species under mild reaction conditions. High level of enantioinduction and excellent isolated yields were achieved in the three‐component reaction of various isatin‐derived ketimines, sulfonyl azides, and terminal alkynes. Control
A new catalytic asymmetric tandem α‐alkenyl addition/proton shift reaction of silyl enol ethers with ketimines was serendipitously discovered in the presence of chiral N,N′‐dioxide/ZnII complexes. The proton shift preferentially proceeded instead of a silyl shift after α‐alkenyl addition of silyl enol ether to the ketimine. A wide range of β‐amino silyl enol ethers were synthesized in high yields with
Catalytic Asymmetric Construction of Vicinal Tetrasubstituted Stereocenters by the Mannich Reaction of Linear α-Substituted Monothiomalonates with Isatin <i>N</i>-Boc Ketimines
A highly diastereo- and enantioselective method for the construction of vicinaltetrasubstitutedstereocenters through the first catalytic asymmetric Mannich reaction of linear α-substituted MTMs with isatin N-Boc ketimines has been developed. This protocol provides atom-economic synthesis of less accessible 3-aminooxindoles bearing vicinaltetrasubstitutedstereocenters. Notably, it also constitutes
been established herein by using a trifluoromethylative ring expansion of isatin with trifluorodiazoethane. The strategy provides a platform for the rapid synthesis of a wide range of substituted 3-hydroxy-4-trifluoromethyl-2-quinolinones. This operationally simple and robust Ag-catalyzed protocol successfully transforms isatin ketimines to 3-amino-4-trifluoromethylquinolinones in excellent yields. The
An efficient asymmetricMannichreaction of isatin-based ketimines with α-diazomethylphosphonates has been developed using a chiral binaphthanol-derived silver phosphate as the catalyst. This reaction allowed the construction of a series of chiral oxindoles bearing a quaternary stereocenter and amino group at the C3 position with up to 95% yields and 99% ee. Those products could be further transformed