To a solution of FLUOLEAD (11.7 g, 46.9 mmol) and Et3N·3HF (7.56 g, 7.68 mL, 46.9 mmol) in anhydrous CH2Cl2(75 mL) at 0 °C was added dropwise a solution of 2-phenylprop-2-en-1-ol (5.03g, 37.5 mmol) in anhydrous CH2Cl2 (75 mL). The mixture was then warmed to r.t. and stirred for 6 h (TLC monitoring). sat. aq K2CO3(190 mL) was then slowly added, the mixture was additionally stirred for 1 h, and then extracted with CH2Cl2 (3 × 120 mL). The combined organic layers were dried (MgSO4) and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, PE 30-40)gave (3-fluoroprop-1-en-2-yl) benzene (3.37 g, 66%).
(JustynaWalkowiak et al. Synthesis,2010, 11, 1883-1890)
FLUOLEAD (2.378 g, 9.5 mmol) and 4-ethoxycarbonyl-1-cyclohexanone (0.851 g, 5 mmol) were placed in a fluoropolymer vessel and dissolved in 10 ml of dry dichloromethane under nitrogen atmosphere. A catalytic amount (2 mmol) of ethanol was added to generate HF. The reaction mixture was stirred at room temperature for 24 h and poured in a saturated sodium bicarbonate solution. The mixture was stirred well, and then the organiclayer was separated, washed with water, dried over anhydrous magnesium sulfate, and filtered. Removal of solvent at reduced pressure gave a residue, which was distilled at reduced pressure to give the product as a colorless liquid (0.816 g, 85%). Its 19F NMR shows that it was a 97:3 mixture of 4-ethoxycarbonyl-1,1-difluorocyclohexaneand 4-ethoxycarbonyl-1-fluoro-1-cyclohexene.