| General/Typical Procedure: Halofluorination of Alkenes with HF·Py/TBCA System; General Procedure. A magnetically stirred mixture of the alkene (2
mmol) and 70% HF·Py (4 mmol) in anhyd CH2Cl2 (10 mL) contained in a 50 mL, single-necked PTFE flask equipped with a septum and under argon, was
treated with trihaloisocyanuric acid (0.68 mmol) at 0 °C. After the addition, the ice bath was removed, and the stirring continued at r.t. After
completion, the reaction was quenched with distilled H2O (10 mL), and the product was extracted with CH2Cl2 (3 × 10 mL). The combined organic layers
were subsequently washed with sat. aq NaHCO3 (10 mL) and dried (Na2SO4). After filtration and evaporation of the solvent, the product was
characterized by standard analytical techniques. 2-Bromo-1-fluoro-1-phenylethane, Conv.: 100%, Colorless liquid, Time: 20 min, Ratio
styrene-HF·Py-TBCA: 1:10:0.34. 1H NMR (200 MHz, CDCl3): δ = 3.5-3.7 (m, 2 H), 5.5-5.8 (ddd, J = 46.9, 7.0, 4.6 Hz, 1 H), 7.4 (m, 5 H). 13C NMR (50
MHz, CDCl3): δ = 34.4 (CH2, d, J = 28.4 Hz), 92.8 (CH, d, J = 178.0 Hz), 125.8 (2 CH, d, J = 6.8 Hz), 128.8 (2 CH, s), 129.3 (CH, s), 137.2 (C, d, J
= 20.3 Hz). 19F NMR (282 MHz, CDCl3): δ = -174.7 (m). MS: m/z (%) = 202 and 204 [M+ and (M + 2)+, 7], 122 (3), 109 (100), 103 (8), 77 (11), 51 (14).
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