Interception of the radicals produced in electrophilic fluorination with radical traps (Tempo, Dmpo) studied by electrospray ionization mass spectrometry.
The interaction of the nitroxide radical traps (Tempo and Dmpo) and radicals produced in the electrophilic fluorination of olefins (styrene and alpha-methylstyrene) and Selectfluor (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octanebis(tetrafluoroborate) (F-TEDA-BF(4)) (1)) was investigated by electrospray ionization mass spectrometry (ESI-MS). Tempo succeeded in intercepting the radical cationic intermediates and the radical adduct ions were detected at m/z 260 (for styrene) and m/z 274 (for alpha-methylstyrene). Dmpo could also intercept the fluorine radical and radical adduct ions were detected at m/z 131, 132 and 152. The interception of the radical cationic intermediates and fluorine radical is good evidence for the presence of a single-electron transfer mechanism in the electrophilic fluorination.
Zhang
Xiang
X
Shanghai Mass Spectrometry Center, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
Wang
Haoyang
H
Guo
Yinlong
Y
D005461:Fluorine / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019097:Spin Trapping / Q000379:methods; D020058:Styrene / Q000737:chemistry; D013343:Styrenes / Q000737:chemistry
D016166:Free Radical Scavengers; D005609:Free Radicals; D006845:Hydrocarbons, Fluorinated; D013343:Styrenes; C027142:vinyltoluene; D005461:Fluorine; D020058:Styrene