GENERAL STEPS: To a solution of 2-bromo-5-fluorobenzyl alcohol (10.05 g, 49 mmol) in anhydrous ethanol (100 mL) was sequentially added NiCl2(dppp) (2.67 g, 4.9 mmol), tetrahydroxydiboron (6.62 g, 74 mmol), triphenylphosphine (0.01 mol), and N,N-diisopropylethylamine (25.7 mL. 148 mmol). The reaction system was degassed under nitrogen protection for 10 min. Subsequently, the reaction mixture was heated to reflux and stirred for 4 hours. After completion of the reaction, it was cooled to room temperature, diluted with water (100 mL) and extracted with ethyl acetate (3 × 50 mL). The organic phases were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to give the crude product 4-fluoro-2-(hydroxymethyl)phenylboronic acid (6), which was used directly in the next step of the reaction. After purification by column chromatography, the target compound was obtained (yield: 62%).
