New Approach to the Detection of Short-Lived Radical Intermediates

• DOI: 10.1021/jacs.2c03618
• Publication Date: 2022-08-24T14:46:35Z
• Authors: Peter J. H. Williams; Graham A. Boustead; Dwayne E. Heard; Paul W. Seakins; Andrew R. Rickard; Victor Chechik
• Keywords: Alkene; Homolysis; Reaction intermediate

We report a new general method for trapping short-lived radicals, based on homolytic substitution reaction SH2′. This departure from conventional radical by addition or radical–radical cross-coupling results in high sensitivity, detailed structural information, and applicability of the approach. The traps this are terminal alkenes possessing nitroxide leaving group (e.g., allyl-TEMPO derivatives). process thus yields stable products which can be stored subsequently analyzed mass spectrometry (MS) supported well-established techniques such as isotope exchange, tandem MS, high-performance liquid chromatography-MS. was applied to range model reactions both gas phases including photoredox-catalyzed thiol–ene alkene ozonolysis. An unprecedented intermediates observed complex mixtures, offering mechanistic insights. Gas-phase radicals detected at concentrations relevant atmospheric chemistry.