3-Ethynylpyridine → 3-[2-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-YL)-vinyl]-pyridine

HRID 1868342Notes

Reaction equation

HRID 1868342 reaction equation
[C:1]([C:3]1[CH:4]=[N:5][CH:6]=[CH:7][CH:8]=1)#[CH:2].[CH3:9][C:10]1([CH3:17])[C:14]([CH3:16])([CH3:15])[O:13][BH:12][O:11]1>C1(C)C=CC=CC=1>[CH3:9][C:10]1([CH3:17])[C:14]([CH3:16])([CH3:15])[O:13][B:12]([CH:2]=[CH:1][C:3]2[CH:4]=[N:5][CH:6]=[CH:7][CH:8]=2)[O:11]1

Participants

4

Reactant 2

HCID 1860033-EthynylpyridineHCID 27347684,4,5,5-Tetramethyl[1,3,2]dioxaborolane

Product 1

HCID 667342383-[2-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-YL)-vinyl]-pyridine

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
50 °C

Procedure

Commercially available 3-ethynyl-pyridine 3b (1.03 g, 10 mmol) and 4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (7.26 mL, 50 mmole) in toluene (40 mL) were combined with carbonylchlorohydridotris(triphenylphosphine) ruthenium (II), RuHCl(CO)(PPh3) (476 mg, 0.50 mmol) at ambient temperature and the reaction mixture was heated at 50° C. in an oil-bath for 16 h. The toluene was evaporated and the crude compound was diluted with ethyl acetate and washed with saturated sodium bicarbonate solution, saturated sodium chloride solution, and water. The organic extracts were dried over MgSO4, filtered, and evaporated in vacuo. The crude product was eluted with a gradient of 10:1 to 2:1 hexane/ethyl acetate by flash chromatography to yield 3-[2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-vinyl]-pyridine Compound 3c (2.2 g, 95% yield) as a yellow syrup. 1H NMR (300 MHz, CDCl3) δ 8.75 (d, 1H), 8.54 (dd, 1H), 7.83 (dt, 1H), 7.39 (d, 1H), 7.31 (dd, 1H), 6.27 (d, 1H), 1.34 (s, 12H); MS (ESI) m/z: 232.14 (M+H+).

Workup

  1. customThe toluene was evaporated
  2. additionthe crude compound was diluted with ethyl acetate
  3. washwashed with saturated sodium bicarbonate solution, saturated sodium chloride solution, and water
  4. dry with materialThe organic extracts were dried over MgSO4
  5. filtrationfiltered
  6. customevaporated in vacuo
  7. washThe crude product was eluted with a gradient of 10:1 to 2:1 hexane/ethyl acetate by flash chromatography

Sources & evidence

ORD record
ord-0033b6c0f3424604884f7ad01b879016
Source dataset
uspto-grants-2009_12
Patent number
US07635703B2

Reaction notes

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