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Updated: Jun 1, 2026

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Rh(I)-catalyzed formal [6 + 2] cycloaddition of 4-allenals with alkynes or alkenes in a tether
Yoshihiro Oonishi1, Akihito Hosotani, Yoshihiro Sato
1Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan. oonishi@pharm.hokudai.ac.jp
Abstract:
Rh(I)-catalyzed formal [6 + 2] cycloaddition of allenal 6 having an alkyne or alkene in a tether proceeded smoothly, giving 5-8- and 6-8-fused bicyclic ketone derivatives 7 in good to excellent yields. It was also found that cyclization of enantiomerically enriched (S)-6a (94% ee) gave cyclic ketone derivative (S)-7a in high yield with reasonable chirality transfer (86% ee). This result indicates that this cyclization proceeds through stereoselective formation of rhodacycle H' followed by insertion of a multiple bond.
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