Fig. 4

Difluorocarbene-oxidation-based trifluoromethoxylation. Isolated yields are shown. Reaction conditions: substrate 1 (0.8 mmol), Ph₃P⁺CF₂CO₂⁻ (2.5 equiv), Ph₂S = O (2.5 equiv), AgF (2 equiv), 2,2′-bipyridine (1.5 equiv), and 2,3,11,12-dibenzo-18-crown-6 (0.5 equiv) in THF (6 mL) at 60 °C for 0.5 h. ^aThe yields in parentheses were determined by ¹⁹F NMR spectroscopy. ^b0.2 mmol of substrate was used. ^c8 mmol of substrate was used.