890839-11-9

74-88-4

890839-11-9

b) General procedure for the synthesis of methyl 2-(4-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)propanoate: under argon protection, a THF solution of methyl 2-(4-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)acetate (1.04 g, 3.78 mmol) ( 3.5 mL, 1.5 M) was added dropwise to THF (6 mL), keeping the reaction temperature at -78 °C. After the dropwise addition, the reaction mixture was slowly warmed up to 0 °C, followed by the addition of iodomethane (3.22 g, 22.6 mmol). The reaction mixture was stirred at room temperature for 1 h. The pH was then adjusted to ~2 by addition of 2 M HCl solution to terminate the reaction. The reaction mixture was extracted with ethyl acetate, the organic phase was concentrated and finally purified by combiflash column chromatography to give a white solid product (0.77 g, 70% yield). The product was characterized by 1H-NMR (CDCl3): δ 1.354 (12H, s), 1.517 (3H, d, J = 7.2 Hz), 3.667 (3H, s), 3.750 (1H, m), 7.323 (2H, d, J = 7.2 Hz), 7.796 (2H, d, J = 7.2 Hz).