Enhanced CO2/Epoxide Cycloaddition Catalyzed by Pyridine-Substituted Triazole-Quaternary Ammonium Bromide
Issued Date
2025-10-14
Resource Type
eISSN
24701343
Scopus ID
2-s2.0-105018646165
Journal Title
ACS Omega
Volume
10
Issue
40
Start Page
46844
End Page
46854
Rights Holder(s)
SCOPUS
Bibliographic Citation
ACS Omega Vol.10 No.40 (2025) , 46844-46854
Suggested Citation
Krisanakaset W., Pornchaiprasartkul P., Nakarajouyphon V., Keawkla N., Surawatanawong P., Chakarawet K., Bunchuay T., Harding D.J., Phomphrai K., Sangtrirutnugul P. Enhanced CO2/Epoxide Cycloaddition Catalyzed by Pyridine-Substituted Triazole-Quaternary Ammonium Bromide. ACS Omega Vol.10 No.40 (2025) , 46844-46854. 46854. doi:10.1021/acsomega.5c04751 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/112665
Title
Enhanced CO2/Epoxide Cycloaddition Catalyzed by Pyridine-Substituted Triazole-Quaternary Ammonium Bromide
Corresponding Author(s)
Other Contributor(s)
Abstract
A series of ionic quaternary ammonium bromides featuring triazole moieties, QAS-trzBn<inf>4</inf>, QAS-trzPic<inf>4</inf>, and QAS-trzBn<inf>2</inf>Pic<inf>2</inf>, were synthesized via Cu-catalyzed azide–alkyne cycloaddition (CuAAC) between propargyl-based ammonium bromide and benzyl- or 2-picolylazide. X-ray crystallographic analyses of QAS-trzBn<inf>4</inf>and QAS-trzBn<inf>2</inf>Pic<inf>2</inf>revealed strong interactions between Br<sup>–</sup>ions and both triazolyl H and methylene H atoms (<sup>+</sup>NCH<inf>2</inf>), as evidenced by short Br<sup>–</sup>···H contacts ranging from 2.68 to 3.00 Å. The catalytic activities of these compounds as bifunctional, single-component catalysts for the CO<inf>2</inf>/epoxide cycloaddition were evaluated under both atmospheric and elevated CO<inf>2</inf>pressures. Notably, catalysts containing pyridyl-triazole groups exhibited superior catalytic performances compared with the benzyl-triazole-based catalyst, QAS-trzBn<inf>4</inf>. A substrate scope study using QAS-trzPic<inf>4</inf>under 20 atm of CO<inf>2</inf>at 100 °C revealed that electron-deficient epoxide substrates were more active, yielding good to excellent conversions (88–100%) to cyclic carbonates within 6 h. Computational studies identified key binding modes in pyridine-substituted systems that position both the epoxide and CO<inf>2</inf>in close proximity. In particular, the QAS-trzPic<inf>4</inf>-CO<inf>2</inf>-epoxide complex is more stabilized than its benzyl derivative, QAS-trzBn<inf>4</inf>-CO<inf>2</inf>-epoxide, due to favorable interactions of CO<inf>2</inf>with the pyridyl substituents.