Rearrangements of the Radical Cations of 3-Aryl-5-fluoroisoxazoles: Further Evidence for Existence of Benzocyclopropenyl Cation

Oksana B Bondarenko; Arseniy I Komarov; Svetlana N Nikolaeva; Tina Holt; Andrei G Kutateladze; Igor P Gloriozov

doi:10.1021/jasms.3c00267

Rearrangements of the Radical Cations of 3-Aryl-5-fluoroisoxazoles: Further Evidence for Existence of Benzocyclopropenyl Cation

J Am Soc Mass Spectrom. 2023 Nov 1;34(11):2547-2555. doi: 10.1021/jasms.3c00267. Epub 2023 Oct 9.

Authors

Oksana B Bondarenko¹, Arseniy I Komarov¹, Svetlana N Nikolaeva¹, Tina Holt², Andrei G Kutateladze², Igor P Gloriozov¹

Affiliations

¹ Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russian Federation.
² Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States.

PMID: 37812762
DOI: 10.1021/jasms.3c00267

Abstract

The fragmentation reaction of the radical cations of 3-aryl-5-fluoroisoxazoles formed via EI-MS is described. A new rearrangement accompanied by fluorine atom migration is discovered. A mechanistic rationale for the rearrangement supporting the existence of a fluorinated benzocyclopropenyl cation was proposed based on the experimental data and quantum chemical calculations.

Keywords: 3-aryl-5-fluoroisoxazoles; DFT calculations; EI-MS fragmentation; F atom migration/rearrangement; fluorinated benzocyclopropenyl cation.