Hydrochloric Acid → (2-Fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)trimethylsilane

Participants

Reaction Conditions

Reaction Steps

A solution of n-BuLi (2.5 M in hexanes; 8.5 mL, 21 mmol, 1.1 equiv) was added to a stirred solution of (4-bromo-2-fluorophenyl)trimethylsilane (4.8 g, 19 mmol, 1.0 equiv) in THF (80 mL) at −78° C. The resulting orange solution was stirred at −78° C. for 15 min. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.4 mL, 21 mmol, 1.1 equiv) was added, and the cloudy orange solution was allowed to slowly warm to 23° C., by allowing the dry ice/acetone bath to melt, and was stirred for 20 h. The reaction mixture was diluted with H2O (200 mL), adjusted to approximately pH=4 using 1 M hydrochloric acid (HCl), and extracted with CH2Cl2 (3×100 mL). The combined organic layers were dried (MgSO4), gravity filtered, and concentrated by rotary evaporation to afford the crude product, (2-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)trimethylsilane, as a pale yellow semisolid (6.0 g, 99% crude yield): 1H NMR (400 MHz, CDCl3) δ 7.55 (dt, J=7.5, 1 Hz, 1H), 7.38-7.42 (m, 2H), 1.34 (s, 12H), 0.29 (d, J=1 Hz, 9H).

Provenance & Evidence