title: A New Strategy for Enantioselective Construction of Multisubstituted Five-Membered Oxygen Heterocycles via a Domino Michael/Hemiketalization Reaction.
abstract: A new highly enantioselective domino Michael/hemiketalization reaction of α-hydroxyacetophenone with β,γ-unsaturated α-keto esters for the synthesis of 2,2,4,5-tetrasubstituted chiral tetrahydrofurans is reported. With 2 mol % intramolecular dinuclear zinc-AzePhenol complex prepared in situ from the reaction of multidentate semi-azacrown ether ligand with ZnEt2 , the corresponding anti-multisubstituted tetrahydrofuran products were obtained in up to 90 % yields, and 98 % enantiomeric excess (ee) at 0 °C for 45 min. Moreover, the products were easily converted to 2,3,5-trisubstituted 2,3-dihydrofurans without any loss in optical activity.
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, 75, Daxue Street, Zhengzhou City, 450052 (China).
authors.forename: Yuan-Zhao
authors.initials: YZ
authors.lastname: Hua
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, 75, Daxue Street, Zhengzhou City, 450052 (China).
authors.forename: Meng-Meng
authors.initials: MM
authors.lastname: Liu
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, 75, Daxue Street, Zhengzhou City, 450052 (China).
authors.forename: Pei-Jin
authors.initials: PJ
authors.lastname: Huang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, 75, Daxue Street, Zhengzhou City, 450052 (China).
authors.forename: Xixi
authors.initials: X
authors.lastname: Song
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, 75, Daxue Street, Zhengzhou City, 450052 (China). wangmincan@zzu.edu.cn.
authors.forename: Min-Can
authors.initials: MC
authors.lastname: Wang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, 75, Daxue Street, Zhengzhou City, 450052 (China). changjunbiao@zzu.edu.cn.
authors.forename: Jun-Biao
authors.initials: JB
authors.lastname: Chang
keywords: Michael/hemiacetalization reactions; asymmetric catalysis; domino reactions; tetrahydrofuran; zinc