title: Formal [4+2]-annulation of vinyl azides with N-unsaturated aldimines.
abstract: Highly functionalized quinolines and pyridines could be synthesized by BF3⋅OEt2-mediated reactions of vinyl azides with N-aryl and N-alkenyl aldimines, respectively. The reaction mechanism could be characterized as formal [4+2]-annulation, including unprecedented enamine-type nucleophilic attack of vinyl azides to aldimines and subsequent nucleophilic cyclization onto the resulting iminodiazonium ion moieties.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 (Singapore), Fax: (+65) 6791-1961.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhu
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Wang
authors.forename: Feng-Lian
authors.initials: FL
authors.lastname: Zhang
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Chiba
mesh_terms: D001386:Azides / Q000737:chemistry*; D003500:Cyclization; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D001386:Azides; D007097:Imines; D011725:Pyridines; D011804:Quinolines; D014753:Vinyl Compounds
keywords: Lewis acids; annulation; azides; heterocycles