title: One-step construction of tetrahydro-5H-indolo[3,2-c]quinolines from benzyl azides and indoles via a cascade reaction sequence.
abstract: A novel one-step assembly of tetrahydro-5H-indolo[3,2-c]quinolines from benzyl azides and indoles via a formal [4 + 2] cycloaddition is described. A cascade reaction sequence, which involves benzyl azide-to-iminium rearrangement followed by two sequential Pictet-Spengler reactions, generates the tetracycles in moderate to excellent yields. The current method is applicable to a broad substrate scope and holds significant potential in constructing polycyclic indolines with tertiary and/or quaternary carbon centers.
authors.affiliation: The State Key Laboratory of Applied Organic Chemistry and School of Pharmacy, Lanzhou University, Lanzhou 730000, China.
authors.forename: Zengqiang
authors.initials: Z
authors.lastname: Song
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Zhao
authors.forename: Hongbin
authors.initials: H
authors.lastname: Zhai
mesh_terms: D001386:Azides / Q000737:chemistry*; D001555:Benzene Derivatives / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001386:Azides; D001555:Benzene Derivatives; D006576:Heterocyclic Compounds, 4 or More Rings; D007211:Indoles; D011804:Quinolines