Title:Enantioselective Synthesis of Coumarins Catalyzed by Chiral Squaramide
Volume: 19
Issue: 11
Author(s): Zhijing Liu, Zhiwei Ma*, Chuanchuan Wang, Degang Ding, Juntao Liu, Xiaopei Chen and Guangwei Geng
Affiliation:
- Faculty of Science, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, P.R. China
- Henan
Cereal Quality and Safety Testing Key Laboratory, Institute of Quality Standards and Testing Technology for Agro-
Products, Henan Academy of Agricultural Sciences, Zhengzhou 450002, P.R. China
Keywords:
Coumarin derivatives, Michael addition, organocatalysis, squaramides, β, γ-unsaturated α-ketoesters, 4-hydroxycoumarin.
Abstract: A newly chiral tertiary amine-squaramide has successfully developed and applied into the
asymmetric Michael addition of 4-hydroxycoumarin to β,γ-unsaturated α-ketoesters. The catalyst system
performed well with a low catalyst loading of 1 mol% under mild reaction conditions. A series of
coumarin derivatives were obtained with good yields and enantioselectivities.
