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Updated: Jun 6, 2025

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
Published on: December 16, 2022
Cyclooctyne End-Functionalized Poly(morpholine-2,5-dione)s
Johanna Schreiber1,2, Natalie E Göppert1,2, Leanne M Stafast1,2
1Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743, Jena, Germany.
This study introduces a novel initiator for controlled polymerization of amino acid-based monomers, creating functional poly(ester amide)s. The cyclooctyne initiator allows for metal-free click chemistry to attach other molecules, enabling customized polymer applications.
Area of Science:
- Polymer Chemistry
- Organic Synthesis
- Materials Science
Background:
- Ring-opening polymerization (ROP) is a key method for synthesizing polymers.
- Functional initiators are crucial for controlling polymer architecture and properties.
- Amino acid-derived monomers offer biocompatibility and tunable properties.
Purpose of the Study:
- To develop a novel cyclooctyne-functionalized initiator for controlled ROP of morpholine-2,5-diones.
- To synthesize well-defined poly(ester amide)s with a cyclooctyne moiety at the alpha-end group.
- To demonstrate the utility of the cyclooctyne group for post-polymerization modification via click chemistry.
Main Methods:
- Organo-catalyzed ring-opening polymerization (ROP) using a binary system of DBU and TU.
- Initiation with (1R,8S,9S)-bicyclo-[6.1.0]non-4-yn-9-ylmethanol (BCN-OH).
- Characterization using 1H NMR, SEC, and MALDI-TOF-MS.
- Strain-promoted azide-alkyne cycloaddition (SPAAC) for block copolymer synthesis.
Main Results:
- Controlled ROP of morpholine-2,5-diones initiated by BCN-OH up to 80% monomer conversion.
- Synthesis of poly(morpholine-2,5-dione)s with low dispersities (≤1.25) and cyclooctyne alpha-end groups.
- Successful synthesis of a block copolymer by coupling a vitamin A-functionalized poly(2-ethyl-2-oxazoline) to the poly(ester amide) via SPAAC.
- Confirmation of block copolymer structure using SEC and DOSY NMR.
Conclusions:
- BCN-OH is an effective initiator for controlled ROP of morpholine-2,5-diones.
- The cyclooctyne moiety enables versatile, metal-free functionalization of poly(ester amide)s.
- This approach provides access to a new generation of customizable functional poly(ester amide)s for diverse applications.
Related Concept Videos
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
Cycloaddition Reactions: MO Requirements for Thermal Activation
Cycloaddition Reactions: Overview
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Structure and Nomenclature of Epoxides

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