[Synthesis]
GENERAL METHODS: Indole derivative (0.3 mmol, 1.0 eq.), sodium trifluoromethanesulfinate (0.6 mmol, 2.0 eq.), 2-tert-butyl anthraquinone (0.06 mmol, 0.2 eq.), and ammonium carbonate (0.18 mmol, 0.6 eq.) were sequentially added to a quartz reaction tube. Hexafluoroisopropanol (0.075 mmol, 0.25 eq.) and acetonitrile (3 mL, 0.1 M) were subsequently added as solvents. The reaction mixture was exposed to 255 nm UV light for 24 hours. Upon completion of the reaction, the reaction was quenched with water and extracted with dichloromethane or ethyl acetate (3 x 30 mL). The organic phases were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent. Finally, the target products 2-trifluoromethylindole and 3-(trifluoromethyl)-1H-indole were obtained by preparative thin-layer chromatography (TLC) using a suitable solvent system. |