title: Ruthenium(II)/chiral Brønsted acid co-catalyzed enantioselective four-component reaction/cascade aza-Michael addition for efficient construction of 1,3,4-tetrasubstituted tetrahydroisoquinolines.
abstract: An elegant synergistic catalytic system comprising a ruthenium complex with a chiral Brønsted acid was developed for a four-component Mannich/cascade aza-Michael reaction. The ruthenium-associated ammonium ylides successfully trapped with in situ generated imines indicates a stepwise process of proton transfer in the ruthenium-catalyzed carbenoid N-H insertion reaction. The different decomposition abilities of various ruthenium complexes towards diazo compounds were well explained by the calculated thermodynamic data. The transformation features a mild, rapid, and efficient method for the synthesis of enantiomerically pure 1,3,4-tetrasubstituted tetrahydroquinolines bearing a quaternary stereogenic carbon center from simple starting precursors in moderate yields with high diastereo- and enantioselectivity.
authors.affiliation: Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, Shanghai, 200062 (China), Fax: (+86) 021-62221237.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Xiaochu
authors.initials: X
authors.lastname: Ma
authors.forename: Changge
authors.initials: C
authors.lastname: Ji
authors.forename: Zhenqiu
authors.initials: Z
authors.lastname: Guo
authors.forename: Taoda
authors.initials: T
authors.lastname: Shi
authors.forename: Shunying
authors.initials: S
authors.lastname: Liu
authors.forename: Wenhao
authors.initials: W
authors.lastname: Hu
mesh_terms: D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D013237:Stereoisomerism; D044005:Tetrahydroisoquinolines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D044005:Tetrahydroisoquinolines; D012428:Ruthenium
keywords: Brønsted acid; multicomponent reactions; ruthenium; synergistic catalysis; tetrahydroisoquinolines