title: Indium-catalyzed [1 + n] annulation reaction between beta-ketoester and alpha,omega-diyne.
abstract: A catalytic amount of In(NTf(2))(3) effects the inter- and intramolecular addition of a beta-ketoester to an alpha,omega-diyne to produce a 1,3-dimethylenecycloalkane derivative in a single step. This [1 + n] annulation reaction shows good functional group tolerance and allows the synthesis of five- to seven-membered carbo- and heterocyclic as well as spirocyclic structures in moderate to excellent yields.
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Tsuji
authors.forename: Iku
authors.initials: I
authors.lastname: Tanaka
authors.forename: Kohei
authors.initials: K
authors.lastname: Endo
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Yamagata
authors.forename: Masaharu
authors.initials: M
authors.lastname: Nakamura
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nakamura