General procedure for the synthesis of 4-(2-pyridyl)phenylboronic acid pinacol ester from isopropanol pinacol borate: 2-(4'-bromophenyl)pyridine (0.468 g, 2 mmol) was dissolved in anhydrous tetrahydrofuran (10 mL) and cooled to -78 °C. At this temperature, n-butyllithium (3 mL, 3.6 mmol) was slowly added dropwise, and stirring of the reaction mixture was continued for 1 hour after completion of the drop. Subsequently, 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.52 mL, 2.5 mmol) was added and the reaction mixture was stirred overnight. Upon completion of the reaction, the reaction was quenched with water and extracted three times with dichloromethane (30 mL). The organic layers were combined, washed with brine and dried over anhydrous magnesium sulfate. After purification by column chromatography (silica gel, eluent ethyl acetate:hexane=1:20), the target product 4-(2-pyridyl)phenylboronic acid pinacol ester was obtained as 0.22 g in 39% yield. Finally, the product was concentrated under vacuum.
