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Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
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Control of dynamic sp3-C stereochemistry.
Aisha N Bismillah1, Toby G Johnson1, Burhan A Hussein1
1Department of Chemistry, Durham University, Durham, UK.
Nature Chemistry
|March 14, 2023
Summary
Researchers discovered dynamic carbon cages that can change their stereochemistry internally. This fluxional behavior, controlled by external factors, impacts stereochemical information transfer in chiral molecules and catalysis.
Area of Science:
- Organic Chemistry
- Stereochemistry
- Supramolecular Chemistry
Background:
- Stereogenic sp3-hybridized carbon centers are key chiral molecule components.
- Unlike dynamic nitrogen centers, sp3-carbon centers are typically fixed, needing external reactions for configuration changes.
Purpose of the Study:
- To report the internal enantiomerization of fluxional carbon cages.
- To investigate the transmission of stereochemical information via adaptive configurations.
Main Methods:
- Utilizing strain-assisted Cope rearrangements for sp3-carbon stereochemistry inversion.
- Employing external reagents to control dynamic enantiomerization.
- Integrating fluxional cages into phosphoramidite-olefin ligands.
Main Results:
- Demonstrated internal enantiomerization of rigid tricyclic carbon cages.
- Showcased control over dynamic enantiomerization (stopping, restarting, slowing) with reagents.
- Observed transmission of stereochemical information from ligands to metal centers.
Conclusions:
- Fluxional carbon cages exhibit dynamic stereochemistry, mimicking other dynamic motifs.
- Cage configuration is influenced by adjacent fixed stereocenters.
- Dynamic cages influence chiral catalysis, ion pairing, and ligand exchange energetics.
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