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

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.