Enantioselective Construction of Tetrahydroquinolin-5-one-Based Spirooxindole Scaffold via an Organocatalytic Asymmetric Multicomponent [3 + 3] Cyclization
journal contributionposted on 15.08.2016, 00:00 by Qiu-Ning Zhu, Yu-Chen Zhang, Meng-Meng Xu, Xiao-Xue Sun, Xue Yang, Feng Shi
The first catalytic enantioselective construction of biologically important tetrahydroquinolin-5-one-based spirooxindole has been developed via a chiral cinchona alkaloid catalyzed asymmetric three-component [3 + 3] cyclization of cyclic enaminone, isatin, and malononitrile, which afforded a series of tetrahydroquinolin-5-one-based spirooxindoles in high yields and with excellent enantioselectivities (up to 99% yield, 97:3 er). This reaction could be applicable to large-scale synthesis of enantioenriched tetrahydroquinolin-5-one-based spirooxindoles. This synthetic methodology will not only provide a unique approach for the construction of chiral tetrahydroquinolin-5-one-based spirooxindole scaffolds but also increase our understanding of catalytic enantioselective multicomponent reactions.