title: Copper(I)-Catalyzed Asymmetric Desymmetrization through Inverse-Electron-Demand aza-Diels-Alder Reaction: Efficient Access to Tetrahydropyridazines Bearing a Unique α-Chiral Silane Moiety.
abstract: An unprecedented copper(I)-catalyzed asymmetric desymmetrization of 5-silylcyclopentadienes with in situ formed azoalkene was realized through an inverse-electron-demand aza-Diels-Alder reaction (IEDDA) pathway, in which 5-silylcyclopentadienes served as efficient enophiles. This new protocol provides a facile access to the biologically important heterocyclic tetrahydropyridazines containing a unique α-chiral silane motif and three adjoining stereogenic centers in generally good yield (up to 92 %) with exclusive regioselectivity, high diastereoselectivity (>20:1 diastereomeric ratio), and excellent enantioselectivity (up to 98 % enantiomeric excess). DFT calculations and control experiments further confirmed the proposed reaction mechanism.
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P. R. China.|State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P. R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wei
authors.affiliation: Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P. R. China.
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Song
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P. R. China.|State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P. R. China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Tao
authors.affiliation: Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Zhenyang
authors.initials: Z
authors.lastname: Lin
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P. R. China.|State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P. R. China.
authors.forename: Chun-Jiang
authors.identifier: http://orcid.org/0000-0003-3629-6889
authors.initials: CJ
authors.lastname: Wang
keywords: Diels-Alder reaction; asymmetric catalysis; desymmetrization; mechanism investigation; α-chiral silanes