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Lookup NU author(s): Dr Simon DohertyORCiD, Dr Julian Knight, Dr Michael Carroll, Ashley Clemmet, Jack Ellison, Tom Backhouse
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).
Styrene-based peroxotungstate-modified polymer immobilized ionic liquid phase catalysts [PO4{WO(O2)2}4]@ImPIILP (Im = imidazolium) are remarkably efficient systems for the selective oxidation of sulfides under mild conditions both in batch and as a segmented or continuous flow process using either ethanol or acetonitrile as solvent or mobile phase, respectively. The performance of these styrene-based systems has been compared against their Ring Opening Metathesis Polymerisation derived counterparts to assess their relative merits. A comparative survey revealed catalyst supported on N-benzyl imidazolium decorated polymer immobilised ionic liquid to be the most efficient and a cartridge packed with a mixture of [PO4{WO(O2)2}4]@ImPIILP and silica operated as a segmented or continuous flow system giving good conversions and high selectivity for sulfoxide. The immobilised catalyst remained highly active for the sulfoxidation of thioanisole in ethanol with a stable conversion-selectivity profile for up to 8 h under continuous flow operation; for comparison conversions with a mixture of [NBu4]3[PO4{WO(O2)2}4] and silica dropped dramatically after only 15 min as a result of rapid leaching while [PO4{WO(O2)2}4]@ImPIILP prepared from commercially available Merrifield resin also gave consistently lower conversions; these benchmark comparisons serve to underpin the potential benefits of preparing the polymer immobilized ionic liquid supports.
Author(s): Doherty S, Knight JG, Carroll MA, Clemmet AR, Ellison JR, Backhouse T, Holmes N, Bourne RA
Publication type: Article
Publication status: Published
Journal: RSC Advances
Year: 2016
Volume: 6
Pages: 73118-73131
Online publication date: 22/07/2016
Acceptance date: 15/07/2016
Date deposited: 15/07/2016
ISSN (electronic): 2046-2069
Publisher: Royal Society of Chemistry
URL: http://dx.doi.org/10.1039/C6RA11157B
DOI: 10.1039/C6RA11157B
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