Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Acid-Catalyzed Ring-Opening of Epoxides02:24

Acid-Catalyzed Ring-Opening of Epoxides

Epoxides that are three-membered ring systems are more reactive than other cyclic and acyclic ethers. The high reactivity of epoxides originates from the strain present in the ring. This ring strain acts as a driving force for epoxides to undergo ring-opening reactions either with halogen acids or weak nucleophiles in the presence of mild acid. The acid catalyst converts the epoxide oxygen, a poor leaving group, into an oxonium ion, a better leaving group, making the reaction feasible. The...
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)01:16

Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)

Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
Preparation of Epoxides03:00

Preparation of Epoxides

Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
Base-Catalyzed Ring-Opening of Epoxides02:26

Base-Catalyzed Ring-Opening of Epoxides

Due to their highly strained structures, epoxides can readily undergo ring-opening reactions through nucleophilic substitution, either in the presence of an acid or a base. The nucleophilic substitution reactions in the presence of acid are called acid-catalyzed ring-opening reactions, and nucleophilic substitution reactions in the presence of a base are called base-catalyzed ring-opening reactions. Epoxides undergo base-catalyzed ring-opening reactions in the presence of a strong nucleophile...
Cationic Chain-Growth Polymerization: Mechanism00:57

Cationic Chain-Growth Polymerization: Mechanism

The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...
Regioselectivity of Electrophilic Additions-Peroxide Effect02:35

Regioselectivity of Electrophilic Additions-Peroxide Effect

In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Dual-component water-lean diamines as high-efficiency CO<sub>2</sub> absorbents: unveiling the two-fold role of proton acceptors.

Chemical communications (Cambridge, England)·2026
Same author

Ultrastrong Polyketone Hot-Melt Adhesives Enabled by Ni-Catalyzed Carbonylative Polymerization.

Journal of the American Chemical Society·2026
Same author

Systematic Catalyst Variation for Improved Stereoselective Epoxide Polymerization: Subtle Modifications Resulting in Superior Efficiency.

Journal of the American Chemical Society·2026
Same author

Intramolecularly Synergic Catalysis Enables Efficient Closed-Loop Recycling of Polyesters and Polycarbonates.

Angewandte Chemie (International ed. in English)·2026
Same author

Living Carbonylative Polymerization of Vinylarenes Using P-Chirogentic Pd Catalyst: A Route to Functionalized Polyketone with Chirality Recognition.

Angewandte Chemie (International ed. in English)·2025
Same author

Stereoconvergent Polymerization Driven by Catalytic Racemization.

Journal of the American Chemical Society·2025

Related Experiment Video

Updated: May 24, 2026

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes
05:48

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Published on: November 21, 2017

π-π Interaction Promoting Kinetic Resolution Copolymerization of rac-Epoxides and Isocyanates.

Long-Tao Pei1, Yong-Qiang Teng1, Bai-Hao Ren1

  • 1State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, China.

Journal of the American Chemical Society
|May 22, 2026
PubMed
Summary

Enantiopure Cobalt(III)-Salen complexes efficiently perform kinetic resolution copolymerization of racemic epoxides and isocyanates. This catalytic approach yields optically active polyurethanes with high enantioselectivity, driven by π-π stacking interactions.

More Related Videos

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
06:49

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

Published on: April 22, 2016

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by &#960;-&#960; Stacking Interactions
10:53

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions

Published on: October 10, 2016

Related Experiment Videos

Last Updated: May 24, 2026

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes
05:48

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Published on: November 21, 2017

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
06:49

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

Published on: April 22, 2016

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by &#960;-&#960; Stacking Interactions
10:53

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions

Published on: October 10, 2016

Area of Science:

  • Polymer Chemistry
  • Organometallic Chemistry
  • Asymmetric Catalysis

Background:

  • Kinetic resolution is crucial for synthesizing enantiopure compounds.
  • Asymmetric polymerization offers routes to chiral polymers.
  • Cobalt(III)-Salen complexes are known catalysts for various organic transformations.

Purpose of the Study:

  • To develop highly enantioselective catalysts for the kinetic resolution copolymerization of racemic epoxides with isocyanates.
  • To investigate the role of catalyst structure and non-covalent interactions in controlling enantioselectivity.
  • To establish a novel strategy for creating stereoregular polymers with main-chain chirality.

Main Methods:

  • Synthesis of enantiopure Co(III)-Salen complexes.
  • Kinetic resolution copolymerization of racemic terminal epoxides with isocyanates.
  • Characterization of resulting polymers (e.g., NMR, GPC).
  • Density functional theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

  • Enantiopure Co(III)-Salen complexes demonstrated high efficiency in kinetic resolution copolymerization.
  • A specific Co(III)-Salen-DNP complex achieved up to 96% enantiomeric excess (ee) in producing optically active polyurethanes.
  • π-π stacking interactions between the catalyst and polymer chain end were identified as key to high enantioselectivity.
  • DFT calculations confirmed the mechanism involving stereoselective epoxide ring-opening.

Conclusions:

  • Co(III)-Salen complexes are effective catalysts for asymmetric polymerization via kinetic resolution.
  • Catalyst design incorporating π-π stacking interactions enhances enantioselectivity.
  • This work provides a new method for synthesizing stereoregular polymers with main-chain chirality.