title: Organocatalytic regioselective asymmetric Michael addition of azlactones to o-hydroxy chalcone derivatives.
abstract: The regioselective and enantioselective Michael addition between azlactones and o-hydroxy chalcone derivatives is reported. Enantiomerically enriched N,O-aminals with two continuous stereogenic centers are exclusively obtained in moderate to good yields with excellent diastereoselectivities and good to excellent enantioselectivities. The experimental results show that an o-hydroxy group on the cinnamenyl motif of chalcone derivatives plays a crucial role at the reaction sites for the regioselective Michael addition. In addition, circular dichroism (CD) spectroscopy and density functional theory (DFT) are used to investigate the absolute configuration of N,O-aminals and the corresponding transition-state structures.
authors.affiliation: Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China. wangxw@suda.edu.cn yowang@suda.edu.cn.
authors.forename: Shao-Yun
authors.initials: SY
authors.lastname: Zhang
authors.forename: Gui-Yu
authors.initials: GY
authors.lastname: Ruan
authors.forename: Zhi-Cong
authors.initials: ZC
authors.lastname: Geng
authors.forename: Nai-Kai
authors.initials: NK
authors.lastname: Li
authors.forename: Ming
authors.initials: M
authors.lastname: Lv
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Xing-Wang
authors.initials: XW
authors.lastname: Wang
mesh_terms: D000080:Acetals / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D002384:Catalysis; D002599:Chalcone / Q000737:chemistry*; D002942:Circular Dichroism; D007783:Lactones / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000080:Acetals; D000588:Amines; D001372:Aza Compounds; D007783:Lactones; D002599:Chalcone; D009584:Nitrogen; D010100:Oxygen