Hydrochloric Acid → 1,2,2-Triphenylvinylboronic acid

HRID 871815Notes

Reaction equation

HRID 871815 reaction equation
C([Li])CCC.Br[C:7]([C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)=[C:8]([C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.[B:27](OCCCC)([O:33]CCCC)[O:28]CCCC.Cl>CCCCCC.C1COCC1.O>[C:21]1([C:7]([B:27]([OH:33])[OH:28])=[C:8]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 12712Tributyl borateHCID 153541-Bromo-1,2,2-triphenyletheneHCID 178418339Butyllithium

Product 1

HCID 99044011,2,2-Triphenylvinylboronic acid

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Procedure

n-Butyllithium in hexane (2.5 M, 15 mL) was added slowly under nitrogen to a stirred solution of (2-bromoethene-1,1,2-triyl)tribenzene (5.00 g, 14.9 mmol) in THF (50 mL) at −78° C. and then the mixture was stirred further for 1 h. Tributyl borate (11.0 mL, 40.8 mmol) was added at −78° C. before the mixture was warmed slowly to room temperature and stirred for 8 hours. Water (100 mL) was added, followed by conc. HCl (100 mL) to acidify the mixture, which was then stirred for 2 hours. The reaction mixture was extracted with EtOAc and the combined organic phases were dried over MgSO4. Concentration under reduced pressure gave 1,2,2-triphenylvinylboronic acid, which, without further purification, was reacted with pinacol (1.73 g, 14.6 mmol) in toluene under reflux for 2 hours to effect condensation by the azeotropic removal of the water formed. The mixture was concentrated under reduced pressure and the residue was purified by column chromatography (hexanes/EtOAc=20/1) to afford D (2.41 g, 65%) as white solid.

Workup

  1. stirringstirred for 8 hours
  2. stirringwas then stirred for 2 hours
  3. extractionThe reaction mixture was extracted with EtOAc
  4. dry with materialthe combined organic phases were dried over MgSO4
  5. concentrationConcentration under reduced pressure

Sources & evidence

ORD record
ord-57446970d0264336893d3deb64c70dbd
Source dataset
uspto-grants-2015_03
Patent number
US08974920B2

Reaction notes

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