4-Bromo-2-fluorophenol (1.9 g, 9.9 mmol), bis(pinacolato)diboron (2.9 g, 11.4 mmol), potassium acetate (3.90 g, 39.7 mmol), and DPPF (0.27 g, 0.49 mmol) were used as raw materials and dissolved in 32 mL 1,4-dioxane. Nitrogen was passed into the solution for 5 min to deoxidize. Subsequently, PdCl2(dppf)-DCM (0.4 g, 0.49 mmol) was added and the reaction mixture was stirred under reflux conditions for 4 hours. Upon completion of the reaction, the reaction solution was filtered through diatomaceous earth and purified by column chromatography to afford the target product 3-fluoro-4-hydroxyphenylboronic acid pinacol ester (2.2 g, 93% yield).1H NMR (CDCl3) δ 7.49 (2H, m), 6.98 (1H, t), 5.31 (1H, brs), 1.33 (12H, s).
