New Approach to the Detection of Short-Lived Radical Intermediates
| Autor: | Peter J. H. Williams, Graham A. Boustead, Dwayne E. Heard, Paul W. Seakins, Andrew R. Rickard, Victor Chechik |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| ISSN: | 0002-7863 1520-5126 |
| Popis: | We report a new general method for trapping short-lived radicals, based on a homolytic substitution reaction SH2′. This departure from conventional radical trapping by addition or radical-radical cross-coupling results in high sensitivity, detailed structural information, and general applicability of the new approach. The radical traps in this method are terminal alkenes possessing a nitroxide leaving group (e.g., allyl-TEMPO derivatives). The trapping process thus yields stable products which can be stored and subsequently analyzed by mass spectrometry (MS) supported by well-established techniques such as isotope exchange, tandem MS, and high-performance liquid chromatography-MS. The new method was applied to a range of model radical reactions in both liquid and gas phases including a photoredox-catalyzed thiol-ene reaction and alkene ozonolysis. An unprecedented range of radical intermediates was observed in complex reaction mixtures, offering new mechanistic insights. Gas-phase radicals can be detected at concentrations relevant to atmospheric chemistry. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|