title: Formation of vinylidenes from internal alkynes at a cyclotriphosphato ruthenium complex.
abstract: A ruthenium cyclotriphosphato (P(3)O(9)(3-)) complex with a labile MeOH ligand can affect the vinylidene rearrangement of general internal alkynes via the 1,2-migration of alkyl, aryl, and acyl groups. This provides the first internal alkyne-to-vinylidene isomerization with high generality. Several intermediary eta(2)-alkyne complexes could be isolated and were successfully transformed into the corresponding vinylidene complexes. The reaction mechanism is also discussed on the basis of a kinetic study and migratory aptitude of alkyl, aryl, and acyl groups; the present reaction proceeds via an intramolecular process and is viewed as an uncommon electrophilic rearrangement.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan.
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Kanao
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kimura
authors.forename: Sou
authors.initials: S
authors.lastname: Kamimura
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Mutoh
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Youichi
authors.initials: Y
authors.lastname: Ishii