title: Diisobutylaluminum hydride promoted cyclization of o-(trimethylsilylethynyl)styrenes to indenes.
abstract: The reaction of o-(trimethylsilylethynyl)styrenes with diisobutylaluminum hydride (DIBAL-H) provides 2-trimethylsilyl-1H-indenes efficiently. The cyclization mechanism involves regioselective hydroalumination of the alkynyl moiety, geometrical isomerization of the alkenylaluminums formed, and intramolecular carboalumination. With substrates bearing a 2-(trimethylsilyl)ethenyl group (R(1) = Me3Si, R(2) = R(3) = H), bis-silylated benzofulvenes are obtained upon treatment of the reaction mixture with an excess amount of benzaldehyde.
authors.affiliation: Department of Applied Chemistry, Graduate School of Science and Engineering, Saitama University , 255 Shimo-ohkubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Kinoshita
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Hirai
authors.forename: Katsukiyo
authors.initials: K
authors.lastname: Miura
mesh_terms: D003500:Cyclization; D007192:Indenes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013343:Styrenes / Q000737:chemistry*; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
chemical_list: D007192:Indenes; D009942:Organometallic Compounds; D013343:Styrenes; D014297:Trimethylsilyl Compounds; C035719:diisobutylaluminum