title: Rhodium-Catalyzed [3+2+2] and [2+2+2] Cycloadditions of Two Alkynes with Cyclopropylideneacetamides.
abstract: It has been established that a cationic rhodium(I)/H8 -binap complex catalyzes the [3+2+2] cycloaddition of 1,6-diynes with cyclopropylideneacetamides to produce cycloheptadiene derivatives through cleavage of cyclopropane rings. In contrast, a cationic rhodium(I)/(S)-binap complex catalyzes the enantioselective [2+2+2] cycloaddition of terminal alkynes, acetylenedicarboxylates, and cyclopropylideneacetamides to produce spiro-cyclohexadiene derivatives which retain the cyclopropane rings.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan).
authors.forename: Tomoka
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan).
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tajima
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan).
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan) http://www.apc.titech.ac.jp/∼ktanaka/
authors.forename: Koji
authors.initials: K
authors.lastname: Masutomi
authors.affiliation: Instrumentation Analysis Center, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan).
authors.forename: Keiichi
authors.initials: K
authors.lastname: Noguchi
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan). ktanaka@apc.titech.ac.jp.|Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan) http://www.apc.titech.ac.jp/∼ktanaka/. ktanaka@apc.titech.ac.jp.|Japan Science and Technology Agency (JST), ACT-C, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012 (Japan). ktanaka@apc.titech.ac.jp.
authors.forename: Ken
authors.initials: K
authors.lastname: Tanaka
keywords: asymmetric catalysis; cycloaddition; heterocycles; rhodium; synthetic methods