1355544-69-2Relevant academic research and scientific papers
An asymmetric Ugi three-component reaction induced by chiral cyclic imines: Synthesis of morpholin- or piperazine-keto-carboxamide derivatives
Zhu, Deguang,Xia, Liang,Pan, Li,Li, Sheng,Chen, Ruijiao,Mou, Yongren,Chen, Xiaochuan
experimental part, p. 1386 - 1395 (2012/03/11)
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.
