title: Formation of Seven-Membered Carbocycles via 7-endo Mode Cyclization of Lithioheptatrienes.
abstract: The highly selective synthesis of triene derivatives was achieved by a zirconocene-mediated three-component coupling reaction, and the trienes were efficiently subjected to 7-endo mode cyclization. The reaction of unsymmetrical zirconacyclopentadienes prepared from two different alkynes with N-bromosuccinimide (NBS) followed by treatment with allyl halides in the presence of CuCl afforded the corresponding heptatrienes in good yields. When the trienes reacted with an organolithium reagent, 7-endo mode cyclization occurred smoothly to give the corresponding cycloheptadiene.
authors.affiliation: Institute for Catalysis and Graduate School of Life Science, Hokkaido University , Kita-ku, Sapporo 001-0021, Japan.
authors.forename: Ken-Ichiro
authors.initials: KI
authors.lastname: Kanno
authors.affiliation: Institute for Catalysis and Graduate School of Life Science, Hokkaido University , Kita-ku, Sapporo 001-0021, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Igarashi
authors.affiliation: Institute for Catalysis and Graduate School of Life Science, Hokkaido University , Kita-ku, Sapporo 001-0021, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Mizukami
authors.affiliation: Department of Chemistry, Aichi University of Education , Igaya, Kariya 448-8542, Japan.
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: Institute for Catalysis and Graduate School of Life Science, Hokkaido University , Kita-ku, Sapporo 001-0021, Japan.
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Song
authors.affiliation: Institute for Catalysis and Graduate School of Life Science, Hokkaido University , Kita-ku, Sapporo 001-0021, Japan.
authors.forename: Tamotsu
authors.identifier: 0000-0003-4728-6547
authors.initials: T
authors.lastname: Takahashi