Under argon protection, 7.0 mg (0.025 mmol) of dichlorobis(trimethylphosphine)nickel(II), 91.4 mg (0.5 mmol) of ethyl 2-chlorobenzoate, 152 mg (1.0 mmol) of cesium fluoride, 140 mg (0.55 mmol) of pinacol bis(borate), 180 mg (1.05 mmol) of trimethyl(2,2,2-trifluoroethoxy)silane, and 0.5 mL of tetrahydrofuran were successively added to the reaction vessel. methyl(2,2,2-trifluoroethoxy)silane and 0.5 mL of tetrahydrofuran, and the reaction vessel was sealed. The reaction mixture was stirred at 100 °C for 2 hours. After completion of the reaction, the reaction vessel was cooled to room temperature and the reaction was quenched by adding 1 mL of saturated aqueous ammonium chloride solution. The reaction mixture was extracted three times with 8 mL of ethyl acetate and the organic phases were combined. The solvent was removed by concentration under reduced pressure and the residue was purified by silica gel column chromatography (eluent ratio: hexane:chloroform:ethyl acetate=16:4:0~16:4:1) to give 107 mg of the white solid product, ethyl 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate, in 78% yield.
