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Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Formation of vinylidenes from internal alkynes at a cyclotriphosphato ruthenium complex
Yousuke Ikeda1, Takafumi Yamaguchi, Keiichiro Kanao
1Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan.
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.
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