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.