3-Ethynylpyridine → 3-((E)-2-(tetramethyl-1,3,2-dioxaborolan-2-yl)ethenyl)pyridine

HRID 1466333Notes

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

Conditions

Temperature: 50 °C

Procedure

An oven-dried round-bottom flask was cooled under N2 (g) and then charged with 3-ethynyl pyridine (104 mg, 1 mmol), toluene (4 mL), and 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.73 mL, 5 mmol). The mixture was purged with argon for 15 min. HRuCl(CO)(PPh3)3 (73 mg, 0.05 mmol) was then added and the reaction heated to 50° C. for 18 h. The reaction was quenched with NaHCO3 (sat.) (10 mL), extracted with EtOAc, and the organic layer washed with brine (10 mL) and then dried over MgSO4. The solvent was removed and the resulting residue purified by column chromatography (silica gel, Hexanes/EtOAc, 1:1) to give the title compound as a white solid (115 mg, 50%). 1H NMR (400 MHz, CDCl3) δ 8.69 (s, 1H) 8.52 (d, 1H, J=4.8 Hz), 7.81 (d, 1H, J=7.8 Hz), 7.38 (d, J=18.6 Hz, 1H), 7.28-7.26 (m, 1H), 6.26 (d, 1H, J=18.5 Hz), 1.33 (s, 12H).

Workup

temperatureAn oven-dried round-bottom flask was cooled under N2 (g)
customThe mixture was purged with argon for 15 min
customThe reaction was quenched with NaHCO3 (sat.) (10 mL)
extractionextracted with EtOAc
washthe organic layer washed with brine (10 mL)
dry with materialdried over MgSO4
customThe solvent was removed
customthe resulting residue purified by column chromatography (silica gel, Hexanes/EtOAc, 1:1)

Sources & evidence

ORD record: ord-3b520cee05344efd92ed234d39b93d63
Source dataset: uspto-grants-2015_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08999968B2

Reaction notes

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