2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 6-(2-((tert-Butyldimethylsilyl)oxy)propan-2-yl)pyridine-3-boronic acid pinacol ester

Participants

Reaction Conditions

Reaction Steps

A solution of 5-bromo-2-(1-{[tert-butyl(dimethyl)silyl]oxy}-1-methylethyl)pyridine (1.63 g, 4.93 mmol) in THF (30 mL) was cooled to −78° C. followed by the addition of n-butyllithium (2.5 M in hexanes, 2.17 mL, 5.43 mmol). After 5 min at −78° C., 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.31 mL, 6.41 mmol) in THF (5.0 mL) was added dropwise, and the reaction was maintained at −78° C. for 10 min. The reaction was allowed to warm to room temperature, quenched with saturated NH4Cl, and extracted with EtOAc (2×). The combined organic layers were washed with brine, dried (MgSO4), filtered, and evaporated. Flash chromatography of the crude residue (0-50% EtOAc/hexanes) afforded the title compound as a colorless solid.

Provenance & Evidence