Stereoselective Synthesis of Chiral Hydrophenanthridines via a One-Pot Stepwise Aza-Michael/Michael/Michael Process
Ruiying Ma, Hongzhou Yang, Ling Ye, Qiang Yang, Zhichuan Shi, Zhigang Zhao, Xuefeng Li
Abstract
A one-pot, two-step aza-Michael/Michael/Michael process was developed to diastereospecifically construct C6a,C10a-cis-hydrophenanthridines in a highly enantioselective manner (83–99% ee). The tricyclic products were provided in 50–99% isolated yields, sequentially promoted by bifunctional squaramide and diamine in a one-pot operation. This doubly annulative protocol indicated that the complicated polycyclic structures could be easily constructed via full employment of the available reaction sites of readily prepared precursors.
Topics & Concepts
Michael reactionSquaramideChemistryBifunctionalEnantioselective synthesisStereoselectivityStereochemistryOrganic chemistryOrganocatalysisCatalysisAsymmetric Synthesis and CatalysisAsymmetric Hydrogenation and CatalysisAdvanced Synthetic Organic Chemistry