title: A facile method for the synthesis of polycyclic indole derivatives: the generation and reaction of tungsten-containing azomethine ylides.
abstract: Treatment of N-(o-alkynylphenyl)imine derivatives with W(CO)(5)(L) induces the 5-endo-mode of cyclization of the imine nitrogen onto the electrophilically activated alkyne moiety to afford a novel reactive species, a metal-containing azomethine ylide. [3 + 2] cycloaddition of this ylide species with various electron-rich alkenes proceeds smoothly to give unstable carbene complexes, which in turn undergo 1,2-hydrogen-, alkyl-, and aryl-migration to afford in good yield 6-5-5 tricyclic indole skeletons having an alkyl or an aryl substituent at the 3-position of the indole nucleus.
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusama
authors.forename: Jun
authors.initials: J
authors.lastname: Takaya
authors.forename: Nobuharu
authors.initials: N
authors.lastname: Iwasawa