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Updated: Feb 12, 2026
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Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
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Palladium-Catalyzed Cyclization/Sulfonylation Enabling Access to 2-Pyrrolidinone-Functionalized Allylic Sulfones
Qing Li1,2, Ying Tian1, Ya-Nan Jia1
1Department of Chemistry, Capital Normal University, Beijing 100048, China.
The Journal of Organic Chemistry
|February 11, 2026
Summary
This study introduces a novel palladium-catalyzed reaction for synthesizing 2-pyrrolidinone-functionalized allylic sulfones using sodium dithionite (Na2S2O4) as a dual sulfur dioxide source and electron donor.
Area of Science:
- Organic Chemistry
- Catalysis
- Sulfur Chemistry
Background:
- Allylic sulfones are valuable synthetic intermediates.
- Efficient methods for their synthesis, particularly those incorporating heterocyclic motifs, are highly sought after.
- Palladium-catalyzed reactions offer powerful tools for C-C and C-heteroatom bond formation.
Purpose of the Study:
- To develop a novel palladium-catalyzed cyclization/sulfonylation reaction.
- To enable the synthesis of 2-pyrrolidinone-functionalized allylic sulfones.
- To utilize sodium dithionite as an inexpensive and effective reagent.
Main Methods:
- Palladium-catalyzed reaction of N-allylbromoacetamides with sodium dithionite and allyl esters.
- Sulfur dioxide insertion into an intermediate.
- Radical cyclization and allylic substitution.
Main Results:
- Successful synthesis of 2-pyrrolidinone-functionalized allylic sulfones.
- Broad substrate scope and excellent functional group tolerance.
- Exclusive (E)-selectivity achieved in the formation of allylic sulfones.
- Sodium dithionite served dual roles as SO2 source and single-electron donor.
Conclusions:
- A novel and efficient Pd-catalyzed method for synthesizing allylic sulfones has been established.
- The reaction provides access to valuable 2-pyrrolidinone-functionalized compounds.
- The use of sodium dithionite offers a cost-effective and sustainable approach.
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