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Updated: Jan 9, 2026
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Secondary Phosphine Oxide Grafted on an Inherently Chiral Calixarene: Synthesis, Resolution, Characterizations, and
Romain Membrat1, Anne-Doriane Manick2, Martin Tlusty3
1Aix Marseille Univ., CNRS, Centrale Med, iSm2, UMR 7113, Marseille 13397, France.
The Journal of Organic Chemistry
|December 2, 2025
Summary
Chiral calixarene-grafted secondary phosphine oxide ligands enabled palladium-catalyzed allylic alcohol isomerization. The calixarene structure provided catalytic activity and asymmetric induction, unlike simpler ligands.
Area of Science:
- Organic Chemistry
- Asymmetric Catalysis
- Supramolecular Chemistry
Background:
- Secondary phosphine oxides (SPOs) are valuable ligands in catalysis.
- Inherently chiral molecules like calixarenes offer unique structural scaffolds.
- Controlling stereochemistry in catalytic reactions is a key challenge.
Purpose of the Study:
- To synthesize and separate stereoisomers of a novel chiral calixarene-grafted SPO.
- To investigate the efficacy of these ligands in palladium-catalyzed allylic alcohol isomerization.
- To evaluate the impact of the calixarene scaffold on catalytic activity and asymmetric induction.
Main Methods:
- Grafting of a secondary phosphine oxide (SPO) unit onto an inherently chiral calixarene.
- Separation of the resulting four stereoisomers using chiral High-Performance Liquid Chromatography (HPLC).
- Palladium-catalyzed isomerization of allylic alcohols using the separated ligands.
Main Results:
- Successful synthesis and separation of four stereoisomers of the calixarene-based SPO.
- Demonstration of catalytic activity and asymmetric induction in allylic alcohol isomerization.
- Observation of a strong confinement effect: cavity-lacking SPO ligands showed no activity or enantioselectivity (ee).
Conclusions:
- The chiral calixarene scaffold is crucial for the observed catalytic activity and asymmetric induction.
- The confinement effect provided by the calixarene structure enhances ligand performance.
- This work presents a novel class of chiral ligands for asymmetric catalysis.
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