title: Chiral Lewis Acid-Catalyzed Enantioselective Cycloadditions between Indoles and Cyclic Carbonyl Ylides Derived from Diazodiketone or Diazoketoester Derivatives.
abstract: Asymmetric 1,3-dipolar cycloaddition reactions between N-methylindoles and several cyclic carbonyl ylides that were derived from diazodiketone or diazoketoester precursors in the presence of both achiral Rh and chiral lanthanoid metal catalysts are described. For the six-membered cyclic carbonyl ylides derived from 1-diazo-5-aryl-2,5-pentanedione precursors, the cycloaddition reactions were carried out using Rh2(OAc)4 (2 mol %) and the chiral Pybox-Ph2-Lu(OTf)3 complex (10 mol %) as catalysts, resulting in high enantioselectivities (83% to >98% ee (exo)) along with relatively good exo-selectivities (exo:endo = 65:35 to 94:6) and yields (63-85%). For the five-membered cyclic carbonyl ylide derived from 1-diazo-2,4-pentandione precursor, the cycloaddition reaction with 5-bromo-1-methylindole was carried out in the presence of Rh2(OAc)4 (2 mol %) and the chiral Pybox-Ph2-Er(OTf)3 complex (30 mol %) as catalysts, resulting in relatively good enantioselectivity (78% ee) and endo-selectivity (endo:exo = 81:19).
authors.affiliation: Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Suga
authors.affiliation: Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan.
authors.forename: Yurie
authors.initials: Y
authors.lastname: Sekikawa
authors.affiliation: Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan.
authors.forename: Shunta
authors.initials: S
authors.lastname: Misawa
authors.affiliation: Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan.
authors.forename: Daito
authors.initials: D
authors.lastname: Kinugawa
authors.affiliation: Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan.
authors.forename: Rinnosuke
authors.initials: R
authors.lastname: Oda
authors.affiliation: Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan.
authors.forename: Kennosuke
authors.initials: K
authors.lastname: Itoh
authors.affiliation: Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Toda
authors.affiliation: Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Wakasato, Nagano 380-8553, Japan.
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Kiyono
mesh_terms: D001391:Azo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D061565:Cycloaddition Reaction; D007211:Indoles / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D001391:Azo Compounds; D007211:Indoles; D058116:Lewis Acids; C093726:5-methylindole