The general procedure for the synthesis of 2-(2-furyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane from 2-bromofuran and isopropanol pinacol borate was as follows: at -78 °C, a hexane solution of n-butyllithium (n-BuLi, 1.6 M, 65 mL, 0.10 mol) was slowly added to a 2-bromofuran (11 g, 0.068 mol) tetrahydrofuran (THF, 200 mL) solution. The reaction mixture was stirred at 0 °C for 2 hours. Subsequently, the reaction mixture was slowly added to a solution of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (13 g, 0.068 mol) in THF (150 mL) at the same temperature. The mixture was gradually warmed to room temperature and stirred overnight. Upon completion of the reaction, a small amount of methanol was added to quench the reaction. The resulting solution was washed three times with water and the organic phase was dried over anhydrous sodium sulfate and subsequently concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using hexane as eluent to afford the target product 2-(2-furyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane.
