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Updated: Dec 23, 2025
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Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
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Rh-Catalyzed Aziridine Ring Expansions to Dehydropiperazines.
Hillary J Dequina1, Josephine Eshon1, William T Raskopf1
1Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States.
Organic Letters
|April 23, 2020
Summary
Researchers developed a new Rh-catalyzed method for synthesizing complex piperazine rings from aziridines and triazoles. This approach offers improved diastereocontrol for pharmaceutical applications.
Area of Science:
- Organic Chemistry
- Catalysis
- Medicinal Chemistry
Background:
- Piperazine scaffolds are crucial in pharmaceuticals but challenging to synthesize with stereochemical complexity.
- Traditional synthetic routes often lack efficient methods for introducing stereocenters into the piperazine ring.
Purpose of the Study:
- To develop a novel catalytic method for constructing stereochemically rich piperazine derivatives.
- To expand synthetic access to complex piperazine scaffolds for drug discovery.
Main Methods:
- Rhodium-catalyzed ring expansion reactions.
- Utilized aziridines and N-sulfonyl-1,2,3-triazoles as starting materials.
- Investigated reaction mechanisms including pseudo-1,4-sigmatropic rearrangements.
Main Results:
- Successfully synthesized dehydropiperazines with high diastereocontrol.
- Demonstrated the utility of rhodium catalysis in piperazine ring formation.
- Identified substrate-dependent competing pathways, such as cheletropic extrusion with pyridotriazoles.
Conclusions:
- The developed Rh-catalyzed method provides efficient access to complex piperazine scaffolds.
- The methodology offers excellent diastereocontrol, valuable for pharmaceutical synthesis.
- Understanding competing reaction pathways is key for optimizing substrate scope.
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