Related Experiment Video
Updated: Jan 10, 2026

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Electrochemical One-Step Synthesis of Alkyne Sulfonates and Sulfonamides: Building Blocks for Highly Substituted
Meysam Azizzade1, Florian A Breitschaft2, Siegfried R Waldvogel2,3
1Department of Chemistry, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany.
Abstract:
Alkyne motifs have a central place in organic synthesis due to their versatility as building blocks for complex molecule construction. The development of efficient and sustainable strategies for the synthesis of functionalized alkynes remains an utmost challenge in modern organic chemistry. Herein, we report a novel and efficient electrochemical multicomponent reaction (eMCR) that enables the one-step synthesis of valuable alkyne sulfonates and sulfonamides using SO2 stock solutions and electric current as a clean oxidant. The generated alkynyl sulfonates and sulfonamides serve as powerful synthetic intermediates, undergoing diverse downstream transformations, including regio- and stereoselective copper-catalyzed dimerizations, hydroarylations, and cyclizations, to access 1,3-dienes, highly substituted alkenes, and heterocycles. Moreover, this method enables late-stage functionalization of complex molecules and pharmaceuticals, demonstrating its significant potential for natural product synthesis, medicinal chemistry, and materials science. The study underscores the promise of electrochemical MCRs as sustainable and versatile tools in modern synthetic methodology.
More Related Videos
05:34Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
Published on: December 16, 2019
12:30Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework
Published on: April 9, 2018
Related Concept Videos
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Preparation and Reactions of Sulfides
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Acidity of 1-Alkynes
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
Preparation of Alkynes: Dehydrohalogenation
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.