2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 4,4,5,5-Tetramethyl-2-(5-phenylfuran-3-yl)-1,3,2-dioxaborolane

To a solution of 4-bromo-2-phenylfuran (1.3 g, 5.8 mmol) in THF (15 mL) was added n-BuLi (2.5M, 2.8 mL, 7.0 mmol) at −78° C. The reaction mixture was kept at −55° C. for 15 min and then 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.3 g, 7.0 mmol) was added at −78° C. The reaction mixture was stirred for 1.5 h and then poured into water/ice solution, extracted with petroleum ether (3×50 mL), dried over anhydrous sodium sulfate and then concentrated in vacuo to give a residue, which was purified by silica gel column chromatography (1% ethyl acetate in petroleum ether) to afford 4,4,5,5-tetramethyl-2-(5-phenylfuran-3-yl)-1,3,2-dioxaborolane as a red oil (300 mg, 19%).