A 100-mL three-neck round-bottomed flask equipped with a reflux condenser, magnetic stirrer and nitrogen inlet was charged with 152c (485 mg, 2.54 mmol), 104g (1.56 g, 5.08 mmol), cesium carbonate (1.66 g, 5.08 mmol), N,N′-dimethylethylene-diamine (447 mg, 5.08 mmol) and 1,4-dioxane (20 mL). After bubbling nitrogen through the resulting suspension for 30 min, copper iodide (484 mg, 2.54 mmol) was added, and the reaction mixture was heated at 100° C. (oil bath temperature) for 16 h. After this time, the mixture was cooled to room temperature and filtered. The filtrate was diluted with ethyl acetate (100 mL) and water (50 mL). The organic layer was separated, and the aqueous layer was extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography to afford a yellow oil, which was dissolved in methylene chloride (5 mL). Acetyl chloride (506 mg, 2.54 mmol) and triethylamine (1.28 g, 12.7 mmol) were added, and the reaction mixture was stirred at room temperature for 2 h. After this time, the reaction mixture was diluted with methylene chloride (50 mL) and saturated aqueous sodium bicarbonate (20 mL). The organic layer was separated, and the aqueous layer was extracted with methylene chloride (3×50 mL). The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure to afford a 13% yield (140 mg) of 152d as a yellow oil: 1H NMR (500 MHz, CDCl3) d 7.60 (d, 1H, J=8.0 Hz), 7.27 (t, 1H, J=8.0 Hz), 7.18 (d, 1H, J=8.0 Hz), 5.26 (d, 1H, J=12.0 Hz), 5.14 (d, 1H, J=12.0 Hz), 4.32 (m, 1H), 4.24 (m, 1H), 4.14 (m, 1H), 3.87 (m, 1H), 2.75 (m, 2H), 2.56 (m, 2H), 2.07 (s, 3H), 1.83 (m, 4H); MS (APCI+) m/z 418.8 (M+H).
