Related Experiment Video
Updated: May 15, 2026

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Palladium- and nickel-catalyzed alkenylation of enolates
Tobias Ankner1, Casey C Cosner, Paul Helquist
1Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden.
Abstract:
Transition-metal-catalyzed alkenylation of enolates provides a direct method to synthesize broadly useful β,γ-unsaturated carbonyl compounds from the corresponding carbonyl compound and alkenyl halides. Despite being reported in the early seventies, this reaction class saw little development for many years. In the past decade, however, efforts to develop this reaction further have increased considerably, and many research groups have reported efficient coupling protocols, including enantioselective versions. These reactions most commonly employ palladium catalysts, but there are also some important reports using nickel. There are many examples of this powerful transformation being used in the synthesis of complex natural products.
More Related Videos
Related Concept Videos
α-Alkylation of Ketones via Enolate Ions
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Aldol Condensation with β-Diesters: Knoevenagel Condensation
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...

