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Published on: August 2, 2012
Consequences of cooperativity in racemizing supramolecular systems
Seda Cantekin1, Huub M M ten Eikelder, Albert J Markvoort
1Institute for Complex Molecular Systems, Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Angewandte Chemie (International Ed. in English)
|May 18, 2012
Summary
Phthalimide-based benzothiazole amide (Phg-BTA) self-assembles into helical structures and exhibits unique racemization with base. Chiral auxiliaries induce deracemization, achieving 32% enantiomeric excess, explained by a theoretical model.
Area of Science:
- Supramolecular Chemistry
- Organic Chemistry
- Chemical Crystallography
Background:
- Self-assembly of molecules into ordered structures is fundamental in chemistry.
- Helical aggregates are of interest for their unique properties and potential applications.
- Understanding molecular behavior in solution, especially racemization and deracemization, is crucial for synthesis and catalysis.
Purpose of the Study:
- To investigate the self-assembly and racemization behavior of Phg-BTA.
- To explore the induction of deracemization using chiral auxiliaries.
- To develop a theoretical model explaining the observed phenomena.
Main Methods:
- Cooperative self-assembly of Phg-BTA into helical aggregates.
- Base-induced racemization studies.
- Chiral auxiliary-mediated deracemization experiments.
- Spectroscopic analysis and theoretical modeling.
Main Results:
- Phg-BTA forms helical aggregates through cooperative self-assembly.
- Unprecedented racemization behavior was observed in the presence of a base.
- Thermodynamically controlled conditions with a chiral auxiliary led to deracemization with 32% enantiomeric excess.
- A theoretical model was developed to elucidate the reaction mechanism.
Conclusions:
- Phg-BTA exhibits unique self-assembly and racemization properties.
- Chiral auxiliaries can effectively control the stereochemical outcome of the reaction.
- The theoretical model provides insights into the mechanism of deracemization in helical aggregates.
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