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
Reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]([C:8]([O:11][Si:12]([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13])([CH3:10])[CH3:9])=[N:6][CH:7]=1.C([Li])CCC.C(O[B:28]1[O:32][C:31]([CH3:34])([CH3:33])[C:30]([CH3:36])([CH3:35])[O:29]1)(C)C>C1COCC1>[Si:12]([O:11][C:8]([C:5]1[CH:4]=[CH:3][C:2]([B:28]2[O:32][C:31]([CH3:34])([CH3:33])[C:30]([CH3:36])([CH3:35])[O:29]2)=[CH:7][N:6]=1)([CH3:10])[CH3:9])([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -78 °C
Procedure
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.
Workup
- temperatureto warm to room temperature
- customquenched with saturated NH4Cl
- extractionextracted with EtOAc (2×)
- washThe combined organic layers were washed with brine
- dry with materialdried (MgSO4)
- filtrationfiltered
- customevaporated
Sources & evidence
- ORD record
- ord-d0f0fe8c187644da9a3a6d43ab0e9ce4
- Source dataset
- uspto-grants-2013_02
- Patent number
- US08367706B2
Reaction notes
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