An Asymmetric Ugi Three-Component Reaction Induced by Chiral Cyclic Imines: Synthesis of Morpholin– or Piperazine–Keto-carboxamide Derivatives
作者:Deguang Zhu、Liang Xia、Li Pan、Sheng Li、Ruijiao Chen、Yongren Mou、Xiaochuan Chen
DOI:10.1021/jo2021967
日期:2012.2.3
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
一系列手性5,6-二氢-1,4-恶嗪-2-酮底物,如预先形成的环状醛亚胺和酮亚胺,首次用于开发新的不对称Ugi三组分反应。亚胺,异氰酸酯和羧酸的Ugi反应使人们可以有效地获得新型的吗啉-2-二-3-甲酰胺化合物。手性亚胺对Ugi产品的新手性中心显示出有希望的立体诱导,并且在大多数情况下获得了主要的反式异构体。添加一些路易斯酸或质子酸可以进一步提高非对映选择性,但通常会导致总收率下降。Ugi-3CR可以扩展到ketopiperazine-2-carboxamide衍生物的立体选择性合成。