Related Experiment Video
Updated: Oct 25, 2026

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents
Published on: November 12, 2016
Electricity-Driven Halogenation of α-Oxo Ketene Dithioacetals Using Lithium Halides as Dual-Function Electrolyte
Austin Symon Abacan1, Thao Nguyen Thanh Huynh2,3, Thanyaporn Kostphan1
1Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok10330, Thailand.
Abstract:
Halogenation reactions are indispensable transformations in organic synthesis. However, they typically rely on toxic reagents or harsh conditions. Herein, we report an electrochemical method for the bromination and chlorination of α-oxo ketene dithioacetals using simple lithium halides as both the halogen source and supporting electrolyte under constant-current electrolysis. The protocol provides direct access to a broad range of brominated and chlorinated α-oxo ketene dithioacetals under additive-free conditions without external chemical oxidants. A total of 22 brominated and 6 chlorinated products were synthesized in up to 99% yield with excellent functional-group tolerance. The practicality of the protocol was further demonstrated through gram-scale electrolysis. Cyclic voltammetry, control experiments, and radical trapping studies suggest distinct anodic oxidation pathways for bromination and chlorination. This operationally simple protocol provides an efficient electrochemical strategy for the halogenation of α-oxo ketene dithioacetals using readily available lithium halides.
More Related Videos
Related Concept Videos
α-Alkylation of Ketones via Enolate Ions
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...
Acid Halides to Alcohols: LiAlH4 Reduction
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
Base-Promoted α-Halogenation of Aldehydes and Ketones
Acid Halides to Ketones: Gilman Reagent
As shown below, the mechanism proceeds in two steps. First, one of the alkyl groups of the reagent acts as a nucleophile and attacks the acyl carbon of the acid chloride to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen double...
Acid Halides to Alcohols: Grignard Reaction
Grignard reagents are a source of carbanions and function as nucleophiles. The mechanism begins with the nucleophilic attack by the carbanion at the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs,...

