Triethylamine → 4,4,5,5-Tetramethyl-2-[2-(1-methyl-3-trimethylsilanyl-prop-2-ynyl)-phenyl]-[1,3,2]dioxaborolane

HRID 563937Notes

Reaction equation

HRID 563937 reaction equation
CCN(CC)CC.[CH3:8][CH:9]([C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][C:17]=1OS(C(F)(F)F)(=O)=O)[C:10]#[C:11][Si:12]([CH3:15])([CH3:14])[CH3:13].[CH3:30][C:31]1([CH3:38])[C:35]([CH3:37])([CH3:36])[O:34][BH:33][O:32]1>O1CCOCC1.CC([O-])=O.CC([O-])=O.[Pd+2].C1(P(C2C=CC=CC=2)C2C=CC=CC=2OC2C=CC=CC=2P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[CH3:30][C:31]1([CH3:38])[C:35]([CH3:37])([CH3:36])[O:34][B:33]([C:17]2[CH:18]=[CH:19][CH:20]=[CH:21][C:16]=2[CH:9]([CH3:8])[C:10]#[C:11][Si:12]([CH3:15])([CH3:14])[CH3:13])[O:32]1

Participants

7

Reactant 3

HCID 8471TriethylamineHCID 27347684,4,5,5-Tetramethyl[1,3,2]dioxaborolaneHCID 11954600Trifluoromethanesulfonic acid 2-[1-methyl-3-(trimethylsilyl)-2-propynyl]phenyl ester

Product 1

HCID 577313094,4,5,5-Tetramethyl-2-[2-(1-methyl-3-trimethylsilanyl-prop-2-ynyl)-phenyl]-[1,3,2]dioxaborolaneYield 86.5%

Reagents, catalysts & solvents 3

HCID 167845palladium(II) acetateCatalystHCID 4285986Bis[2-(diphenylphosphino)phenyl] etherCatalystHCID 312751,4-DioxaneSolvent

Conditions

Temperature
60 °C

Procedure

A mixture of 547 mg (2.44 mmol, 0.03 eq) of Pd(OAc)2 and 2.63 grams (4.88 mmol, 0.06 eq) of bis[2-(diphenylphosphino)phenyl]ether (DPEphos) was stirred in 163 mL of dioxane in a 500 mL round bottom flask under argon at room temperature. To this heterogenous mixture was sequentially added 22.7 mL (163 mmol, 2.0 eq) of Et3N and 28.5 grams (81.3 mmol, 1.0 eq) of triflate 7. Lastly, 17.6 mL (122 mmol, 1.5 eq) of 4,4,5,5-Tetramethyl-1,3,2-dioxaborolane was added and the mixture was sparged with argon for 10 minutes. The reaction was then heated to 60° C. in a silicon oil bath and stirred until complete by 1H-NMR (aliquots removed periodically). Upon completion (˜19 hours) the mixture was cooled to room temperature and diluted with Et2O. The solution was then washed with water and the water layer was back extracted with Et2O. The combined Et2O layers were washed with brine and dried over MgSO4. Concentration and silica gel chromatography (hexane/EtOAc) gave 23.1 grams (86%) of 9 as a yellow oil, Rf 0.64 (1:1 hexane:EtOAc). 1H-NMR (500 MHz, CDCl3): 7.81 (1H, d, J=7.1 Hz), 7.75 (1H, d, J=7.8 Hz), 7.47 (1H, d, J=7.6 Hz), 7.24 (1H, d, J=7.4 Hz), 4.73 (1H, q, J=7.1 Hz), 1.45 (3H, d, J=7.1 Hz), 1.36 (6H, s), 1.35 (6H, s), 0.215 (9H, s). 13C-NMR (500 MHz, CDCl3): 150.25, 136.35, 131.64, 126.85, 125.94, 111.34, 85.66, 83.77, 31.52, 26.29, 25.17, 24.93, 0.45. IR (cm−1): 2975 (m), 2165 (m), 1598 (m), 1441 (m), 1380 (m), 1346 (s), 1249 (m), 1145 (m), 842 (s) HRMS (EI) calcd. for C19H29BO2Si: 328.2030. found: 328.2028.

Workup

  1. customthe mixture was sparged with argon for 10 minutes
  2. customremoved periodically)
  3. temperatureUpon completion (˜19 hours) the mixture was cooled to room temperature
  4. additiondiluted with Et2O
  5. washThe solution was then washed with water
  6. extractionthe water layer was back extracted with Et2O
  7. washThe combined Et2O layers were washed with brine
  8. dry with materialdried over MgSO4
  9. concentrationConcentration and silica gel chromatography (hexane/EtOAc)

Sources & evidence

ORD record
ord-246698e4f5bb471bbbcacd1cb998ad13
Source dataset
uspto-grants-2011_11
Patent number
US08067583B2

Reaction notes

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