title: Asymmetric Michael Addition of Aldimino Esters with Chalcones Catalyzed by Silver/Xing-Phos: Mechanism-Oriented Divergent Synthesis of Chiral Pyrrolines.
abstract: The mechanism-oriented reaction design for the divergent synthesis of chiral molecules from simple starting materials is highly desirable. In this work, aromatic amide-derived nonbiarylatropisomer/silver (silver/Xing-Phos) complex was used to catalyze the Michael addition of glycine aldimino esters to chalcones and successfully applied to the subsequent cyclocondensation to afford substituted cis-Δ(1)-pyrroline derivatives with up to 98 % ee. Besides the inherent performance of the chiral Ag/Xing-Phos catalyst system, it was found that the workup of such reactions played an important role for the stereoselective construction of stereodivergent Δ(1)-pyrrolines, in which an epimerization of the cis-Δ(1)-pyrrolines to the trans-isomers during was revealed.
authors.affiliation: State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics (CAS) and, University of the Chinese Academy of Sciences, P. R. China.
authors.forename: Xing-Feng
authors.initials: XF
authors.lastname: Bai
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, P. R. China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, P. R. China.
authors.forename: Zhan-Jiang
authors.initials: ZJ
authors.lastname: Zheng
authors.affiliation: State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics (CAS) and, University of the Chinese Academy of Sciences, P. R. China. cgxia@licp.cas.cn.
authors.forename: Chun-Gu
authors.initials: CG
authors.lastname: Xia
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, P. R. China.
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Cui
authors.affiliation: State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics (CAS) and, University of the Chinese Academy of Sciences, P. R. China. liwenxu@hznu.edu.cn.|Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, P. R. China. liwenxu@hznu.edu.cn.
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Xu
keywords: Michael reaction; asymmetric catalysis; pyrrolines; silver; stereodivergent synthesis