Stereoselective Synthesis of Chiral Hydrophenanthridines via a One-Pot Stepwise Aza-Michael/Michael/Michael Process.
Journal: Organic Letters
Published:
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.
Authors
Ruiying Ma, Hongzhou Yang, Ling Ye, Qiang Yang, Zhichuan Shi, Zhigang Zhao, Xuefeng Li