A cyclochiral conformational motif constructed using a robust hydrogen-bonding network.
Kenji Mishiro1, Takumi Furuta, Takahiro Sasamori
1Institute for Chemical Research, Kyoto University , Uji, Kyoto, 611-0011, Japan.
Journal of the American Chemical Society
|September 7, 2013
Summary
Researchers discovered a novel molecular structure with a strong hydrogen-bonding network, creating a cyclochiral shape. This chiral structure was used for resolving secondary alcohols and showed tunable handedness, offering new possibilities in molecular design.
Area of Science:
- Organic Chemistry
- Supramolecular Chemistry
- Stereochemistry
Background:
- Intramolecular hydrogen bonding (H-bonding) is crucial for molecular conformation.
- Designing molecules with predictable and controllable chiral properties remains a significant challenge in chemistry.
Purpose of the Study:
- To discover and characterize a novel conformational motif driven by a robust intramolecular H-bonding network.
- To investigate the formation of cyclochiral structures and their handedness.
- To explore the application of this motif in asymmetric synthesis, specifically acylative kinetic resolution.
Main Methods:
- Synthesis of a pyrrolidine derivative with four identical amide substituents.
- Structural analysis using Nuclear Magnetic Resonance (NMR) spectroscopy, X-ray crystallography, and theoretical calculations.
- Application in the acylative kinetic resolution of secondary alcohols.
Main Results:
- A novel pyrrolidine derivative formed a strong intramolecular H-bonding network involving all amide groups.
- This network induced a cyclochiral structure with handedness dependent on H-bonding directionality.
- The compound's handedness could be influenced by chiral substituents and switched by external stimuli.
- Successful application in the acylative kinetic resolution of secondary alcohols was demonstrated.
Conclusions:
- A new conformational motif based on a strong intramolecular H-bonding network has been established.
- The discovered cyclochiral structure exhibits controllable handedness, applicable to asymmetric synthesis.
- This work provides insights into the relationship between H-bonding networks, molecular conformation, and chirality.
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