Related Experiment Video
Updated: Jul 7, 2026

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
Published on: December 16, 2022
E → Z Photoisomerization of Cinnamamides Using a Mixed-Solvent System in a Recycling Photoreactor
Mayuko Suga1, Saki Fukushima1, Souta Nakagawa1
1Faculty of Pharmaceutical Sciences, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
This study improved E-alkene to Z-alkene conversion using a recycling photoreactor. Mixed solvents containing n-hexane enhanced photoisomerization and chromatographic separation for Weinreb amides.
Area of Science:
- Organic Chemistry
- Photochemistry
- Green Chemistry
Background:
- E-alkene to Z-alkene isomerization is crucial for synthesizing various organic compounds.
- Recycling photoreactors offer a sustainable approach to photochemical synthesis.
- Optimizing solvent systems is key to improving reaction efficiency and product purification.
Purpose of the Study:
- To enhance the efficiency of E-alkene to Z-alkene photoisomerization using a recycling photoreactor.
- To investigate the impact of different solvent systems on the photoisomerization of E-alkenes bearing Weinreb amides or pinacolborane functionalities.
- To improve the chromatographic separation of Z-alkenes produced via photoisomerization.
Main Methods:
- Utilized a recycling photoreactor for E-alkene to Z-alkene isomerization.
- Examined E-alkenes with Weinreb amide and pinacolborane functional groups.
- Tested various solvent systems, including acetonitrile, n-hexane, ethanol, and ethyl acetate, often in mixtures.
- Employed High-Performance Liquid Chromatography (HPLC) for product analysis and separation.
Main Results:
- Acetonitrile as a solvent yielded unsatisfactory results for E-alkene to Z-alkene conversion.
- Photoisomerization proceeded effectively in mixed solvents, particularly those rich in n-hexane.
- Mixed solvents of ethanol or ethyl acetate in n-hexane significantly accelerated the photoisomerization of cinnamic acid-derived Weinreb amides.
- Improved chromatographic separation of Z-alkenes was achieved using these mixed solvent systems.
Conclusions:
- Mixed solvents containing n-hexane are effective for efficient Z-alkene production via photoisomerization in recycling photoreactors.
- The use of mixed solvents enhances both the reaction rate and chromatographic purification of Z-alkenes bearing Weinreb amides.
- This study highlights the potential of n-hexane-containing mixed solvents for broader applications in photoreactions.
More Related Videos
12:19Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
09:22Synthesis and Performance Evaluations of ZnCoS/ZnCdS with Twin Crystal Structure for Multifunctional Redox Photocatalysis in Energy Applications
Published on: July 25, 2025
Related Concept Videos
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Thermal and Photochemical Electrocyclic Reactions: Overview
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Cycloaddition Reactions: MO Requirements for Photochemical Activation
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement