Triisopropyl borate → HCID 11289381, compound
Reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([O:8][Si:9]([CH:16]([CH3:18])[CH3:17])([CH:13]([CH3:15])[CH3:14])[CH:10]([CH3:12])[CH3:11])=[CH:4][CH:3]=1.C([Li])CCC.[B:24](OC(C)C)([O:29]C(C)C)[O:25]C(C)C>C1COCC1>[CH:10]([Si:9]([CH:16]([CH3:18])[CH3:17])([CH:13]([CH3:15])[CH3:14])[O:8][C:5]1[CH:6]=[CH:7][C:2]([B:24]([OH:29])[OH:25])=[CH:3][CH:4]=1)([CH3:12])[CH3:11]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
To a stirring solution of 4-(triisopropyl)silyloxy-1-bromobenzene (6) (540 mg, 1.64 mmol) in THF (15 ml) at −78° C. was added n-butyl lithium (0.9 ml, 2.18 M in hexanes, 1.96 mmol) dropwise. The reaction mixture was stirred for 30 minutes then triisopropyl borate (0.5 ml, 2.17 mmol) was added in one portion. The reaction was stirred at −78° C. for 1 hour, allowed to warm to ambient temperature over 4 hours, quenched with 3 N HCl (5 ml) and stirred for 30 minutes at 0° C. The aqueous layer was extracted with ethyl acetate (3×) and the combined organic layers were dried over MgSO4. Purification by flash SiO2 chromatography (loaded with DCM, eluted with hexanes/ethyl acetate (10:1) to (3:1) to (1:1)) gave 7 as a white solid (328 mg, 68% yield): 1H-NMR (400 MHz, chloroform-d) δ 8.10 (d, J=8.4 Hz, 2H), 6.98 (d, J=8.4 Hz, 2H), 1.30 (septet, J=7.6 Hz, 3H), 1.13 (d, J=7.6 Hz, 18H); 13C-NMR (100 MHz, chloroform-d) δ 160.1, 137.4, 119.6, 17.9, 12.7.
Workup
- stirringThe reaction was stirred at −78° C. for 1 hour
- customquenched with 3 N HCl (5 ml)
- stirringstirred for 30 minutes at 0° C
- extractionThe aqueous layer was extracted with ethyl acetate (3×)
- dry with materialthe combined organic layers were dried over MgSO4
- customPurification
- washby flash SiO2 chromatography (loaded with DCM, eluted with hexanes/ethyl acetate (10:1) to (3:1) to (1:1))
Sources & evidence
- ORD record
- ord-c93f343557b4451b962be4155cba2f62
- Source dataset
- uspto-grants-2008_04
- Patent number
- US07355079B2
Reaction notes
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