2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → (2-(Cyclopropylmethoxy)-5-fluorophenyl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of Example 274a (0.1 g, 0.408 mmol) in tetrahydrofuran (2 mL) at −20° C. was added nBuLi (0.180 mL of a 2.5 M solution in hexanes, 0.449 mmol). The reaction mixture was stirred for 2 hours, then cooled to −40° C. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.092 mL, 0.449 mmol) was added dropwise. The reaction mixture was stirred for 30 minutes. The reaction mixture was quenched with 1M citric acid at 0° C. The mixture was stirred at ambient temperature for 1 hour and then extracted with ethyl acetate. The layers were separated, and the organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated. The crude material was purified by flash chromatography (silica gel, 10-33% ethyl acetate/hexanes gradient) to provide the title compound (23 mg, 20% yield).

Provenance & Evidence