10.1021/jo2021967.s001 Deguang Zhu Deguang Zhu Liang Xia Liang Xia Li Pan Li Pan Sheng Li Sheng Li Ruijiao Chen Ruijiao Chen Yongren Mou Yongren Mou Xiaochuan Chen Xiaochuan Chen An Asymmetric Ugi Three-Component Reaction Induced by Chiral Cyclic Imines: Synthesis of Morpholin– or Piperazine–Keto-carboxamide Derivatives American Chemical Society 2012 chiral center preformed cyclic aldimines stereoselective synthesis proton acids Lewis acids Chiral Cyclic Imines carboxylic acids Ugi reaction Ugi products chiral imines 2012-02-03 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/An_Asymmetric_Ugi_Three_Component_Reaction_Induced_by_Chiral_Cyclic_Imines_Synthesis_of_Morpholin_or_Piperazine_Keto_carboxamide_Derivatives/2553466 A series of chiral 5,6-dihydro-1,4-oxazin-2-one substrates, as preformed cyclic aldimines and ketoimines, were employed to develop a new asymmetric Ugi three-component reaction for the first time. The Ugi reaction of the imines, isocyanides, and carboxylic acids opens an efficient access to novel morpholin-2-one-3-carboxamide compounds. The chiral imines showed promising stereoinduction for the new chiral center of the Ugi products, and predominant trans-isomers were obtained in the most cases. Addition of some Lewis acids or proton acids could improve the diastereoselectivity further but usually led to a drop in total yield. The Ugi-3CR could be extended to the stereoselective synthesis of ketopiperazine-2-carboxamide derivatives.