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Updated: Jun 11, 2025

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
A Unified Synthesis of Electron-Deficient 1,4- and 1,1,4-Substituted 1,3-Dienes through a Base-Promoted Allylation
Ayelet Rothstein1, Lena Trifonov1, Niv Keidar1
1Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel.
Abstract:
We disclose a general 2-step synthesis of electron-poor 1,4- and 1,1,4-substituted buta-1,3-dienes bearing electron-withdrawing substituents at both termini of the conjugated system. The method relies on a base-promoted C-allylation of primary or secondary alkylsulfones with γ-bromocrotonate or related amide, nitrile, or sulfone and subsequent vinylogous retro-Michael dehydrosulfinylation. The geometry of the resulting dienes is substrate-dependent, and predominantly E,E-dienes are formed from E-electrophiles. This phosphorus- and transition-metal-free method tolerates a variety of functionalities and could serve as a supplement to Wittig, HWE, and Julia olefinations.
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