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A General Strategy to Access All Stereosequences in a Synthetic Polymer
Ranajit Barman1, Jean-François Lutz1
1Université de Strasbourg, CNRS, ISIS, 8 allée Gaspard Monge, 67000 Strasbourg, France.
Journal of the American Chemical Society
|November 6, 2025
Summary
Researchers developed a new iterative phosphoramidite chemistry method to precisely control polymer stereochemistry. This breakthrough enables the synthesis of novel polymer stereosequences beyond traditional isotactic and syndiotactic patterns.
Area of Science:
- Polymer Chemistry
- Organic Synthesis
- Materials Science
Background:
- Controlling stereocenters in polymer main chains is a significant challenge.
- Conventional polymerization methods yield limited stereochemical patterns: isotactic, syndiotactic, and heterotactic.
Purpose of the Study:
- To develop a novel method for accessing a broader range of polymer stereochemical patterns.
- To synthesize poly(phosphodiester amide)s with precisely defined stereosequences.
Main Methods:
- Utilized iterative phosphoramidite chemistry for automated solid-phase synthesis.
- Synthesized two monomers with opposite configurations at a carbon stereocenter.
- Employed high-resolution mass spectrometry, ion-exchange HPLC, NMR spectroscopy, and circular dichroism for characterization.
Main Results:
- Achieved high coupling efficiencies, enabling exact polymer chain lengths and primary structures.
- Synthesized perfectly isotactic and syndiotactic polymers (100% m or r dyads).
- Enabled access to nonclassical stereosequences, including periodic, stereomutated, and stereocoded arrangements, with potential for over one million unique sequences.
Conclusions:
- Established a new paradigm in stereocontrolled polymer synthesis.
- Expanded the structural and functional possibilities of synthetic macromolecules.
- Demonstrated unprecedented precision in controlling polymer stereochemistry.
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