4-Bromobiphenyl → 1,1'-Biphenyl-4-yl-boronic acid
Reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)=[CH:4][CH:3]=1.C([Li])CCC.C([O:22][B:23](OC(C)C)[O:24]C(C)C)(C)C>C1COCC1>[C:5]1([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:6]=[CH:7][C:2]([B:23]([OH:24])[OH:22])=[CH:3][CH:4]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
4-Biphenylboronic acid was prepared differently than described in the literature (see Yabroff, D. L.; Branch, G. E.; Bettman, B. J. Am. Chem. Soc. 1934, 56, 1850-1857). To a solution of 4-bromobiphenyl (2.00 g, 8.58 mmol) in THF (20 mL) at −78° C. was added n-butyllithium (4.0 mL of 2.5 M in hexanes) in a slow stream via syringe. After 15 minutes, triisopropylborate (3.0 mL, 13 mmol) was added in a slow stream via syringe. After 10 minutes, the resultant homogeneous solution was allowed to warm to ambient temperature over 45 minutes and partitioned between EtOAc (50 mL) and 10% aqueous HCl (50 mL). The aqueous layer was separated and extracted with more EtOAc. The combined organic layers were washed with brine, dried over Na2SO4 and concentrated to give a crude product which was triturated with hexanes to yield 1.53 g (90%) of 4-biphenylboronic acid as a white solid.
Workup
- waitAfter 10 minutes
- custompartitioned between EtOAc (50 mL) and 10% aqueous HCl (50 mL)
- customThe aqueous layer was separated
- extractionextracted with more EtOAc
- washThe combined organic layers were washed with brine
- dry with materialdried over Na2SO4
- concentrationconcentrated
- customto give a crude product which
Sources & evidence
- ORD record
- ord-d9054bf4db814d3b9bdeae44438c20d9
- Source dataset
- uspto-grants-2001_10
- Patent number
- US06306892B1
Reaction notes
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