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Base-Catalyzed Hydroarsination at Ambient Temperature: Synthesis in Green Solvent
Emma J Finfer1, Noah LaMonda1, Rory Waterman1,2
1Department of Chemistry, University of Vermont, Burlington, Vermont 05405, United States.
Inorganic Chemistry
|May 19, 2026
Summary
A new, metal-free hydroarsination method uses sodium hydroxide (NaOH) to create novel tertiary arsines from simple starting materials. This accessible reaction offers improved yields and greener conditions for synthesizing diverse organoarsenic compounds.
Area of Science:
- Organometallic Chemistry
- Synthetic Organic Chemistry
- Green Chemistry
Background:
- Hydroarsination, the addition of an arsenic-hydride bond across an unsaturated moiety, is an underdeveloped area in synthetic chemistry.
- Existing methods often require transition metal catalysts, limiting substrate scope and increasing costs and purification complexity.
- There is a need for practical, efficient, and environmentally friendly hydroarsination protocols.
Purpose of the Study:
- To develop a novel, transition-metal-free hydroarsination protocol.
- To enable the synthesis of previously inaccessible tertiary arsines.
- To achieve regioselective anti-Markovnikov addition under mild conditions.
Main Methods:
- Utilized a catalytic amount of commercially available, air-stable sodium hydroxide (NaOH) in dimethyl sulfoxide (DMSO).
- Investigated the reaction with various substrates including vinylarenes, Michael acceptors, and alkynes.
- Employed deuterium labeling studies to elucidate the reaction mechanism.
Main Results:
- Achieved regioselective anti-Markovnikov addition of diphenylarsine to diverse unsaturated compounds at ambient temperature.
- Synthesized previously unknown tertiary arsines in good to quantitative yields.
- Demonstrated a nucleophilic mechanism initiated by arsine deprotonation, with NaOH playing a dual role in base activation and water management.
Conclusions:
- The developed NaOH-catalyzed hydroarsination protocol is a practical, cost-effective, and green alternative to existing methods.
- This methodology significantly expands the scope and accessibility of structurally diverse tertiary arsines.
- The simplified procedure offers improved activity, broader substrate scope, and easier purification compared to prior catalysts.
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