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Treichel M, Xun R, Williams CF, Gaitor JC, MacMillan SN, Vinskus JL, Womble CT, Kowalewski T, Noonan KJT. Examining the Alkaline Stability of Tris(dialkylamino)sulfoniums and Sulfoxoniums. J Org Chem 2022; 87:15732-15743. [PMID: 36383039 DOI: 10.1021/acs.joc.2c01289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Herein, a synthetic method was developed to prepare a series of tris(dialkylamino)sulfonium and sulfoxonium cations from sulfur monochloride. Alkaline stability studies of these two cation families in 2 M KOH/CD3OH solution at 80 °C revealed how degradation pathways change as a function of the oxidation state of the S center, as determined by 1H NMR spectroscopy. The sulfonium cations (+S(NR2)3) typically degrade by nucleophilic attack at the sulfur atom with loss of an amino group and a proton transfer reaction to produce sulfoxides, while the sulfoxoniums (+O═S(NR2)3) tend to degrade by loss of an R group to form sulfoximines. From the group of sulfoniums and sulfoxoniums explored in this work, the tris(piperidino)sulfoxonium cation was noted to have excellent alkaline stability. This sulfoxonium should be suitable for future examination as a tethered cation in anion-exchange membranes (AEMs), or as a phase-transfer catalyst in biphasic reactions.
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Affiliation(s)
- Megan Treichel
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Ruiran Xun
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Camille F Williams
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Jamie C Gaitor
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14850, United States
| | - Jessica L Vinskus
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - C Tyler Womble
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Tomasz Kowalewski
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Kevin J T Noonan
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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