The compound benzyl bromide (2 g, 11.7 mmol) was dissolved in anhydrous DMF (40 mL), and after the addition of pinacol ester of biboronic acid (4.45 g, 17.5 mmol), cuprous bromide (340 mg, 2.3 mmol), and sodium tert-butoxide (1.69 g, 17.5 mmol), it was protected by exchanging the air in the reaction flask with argon, and the reaction was carried out for 10 hours at 80 C. The reaction was carried out at 80C for 10 hours. The reaction was cooled to room temperature, filtered to remove the insoluble material, the filter cake was washed with a small amount of ethyl acetate, the filtrates were combined and extracted with ethyl acetate by adding an appropriate amount of water. The organic layer was collected and dried with anhydrous sodium sulfate, concentrated under reduced pressure and purified by silica gel column chromatography (eluent PE/EtOAc = 40:1) to obtain the product colorless oily 1.78 g, yield 70%.
