C(=O)([O-])[O-].[K+].[K+].[Br:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1B(O)O.Br[C:18]1[CH:23]=[CH:22][C:21]([C:24]([CH3:27])([CH3:26])[CH3:25])=[CH:20][CH:19]=1.N#N.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C([O-])(=O)C.[Pd+2].C([O-])(=O)C.COCCOC.O>[Br:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1[C:18]1[CH:23]=[CH:22][C:21]([C:24]([CH3:27])([CH3:26])[CH3:25])=[CH:20][CH:19]=1
To a 250-mL round bottom flask equipped with a magnetic stir bar was added water (41 mL) and 1,2-dimethoxyethane (41 mL). The solution was sparged with nitrogen for 20 minutes, then potassium carbonate (6.49 g, 46.9 mmol, 3 equiv), 2-bromophenylboronic acid (3.69 g, 18.4 mmol, 0.98 equiv) and 1-bromo-4-tert-butylbenzene (4.00 g, 18.8 mmol, 1 equiv) were added. The flask was then purged with N2 for 10 minutes before finally adding palladium(II) acetate (84 mg, 0.375 mmol, 0.02 equiv) and triphenylphosphine (394 mg, 1.50 mmol, 0.08 equiv). The reaction mixture was heated to 85° C. under a positive pressure of nitrogen for 18 hours. After cooling to room temperature, the phases were partitioned and the organic layer was collected. The aqueous layer was washed with ethyl acetate (3×20 mL). The combined organic fractions were washed with brine (50 mL), dried over sodium sulfate, filtered, and concentrated on a rotary evaporator. The crude yellow oil was purified by column chromatography on an Isco CombiFlash system (120-g column; eluted with 14 column volumes heptane) to afford the title compound as a colorless oil (2.93 g, 67 area % by HPLC, 54% yield). 1H NMR (400 MHz, CDCl3) δ ppm 7.68-7.64 (m, 1H), 7.48-7.42 (m, 2H), 7.39-7.31 (m, 4H), 7.21-7.15 (m, 1H), 1.39 (s, 9H).
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