Trimethylsilylacetylene → 2,2,4,4-Tetramethyl-7-trimethylsilylethynyl-chroman

HRID 2226117Notes

Reaction equation

[CH3:1][C:2]1([CH3:15])[CH2:11][C:10]([CH3:13])([CH3:12])[C:9]2[C:4](=[CH:5][C:6](Br)=[CH:7][CH:8]=2)[O:3]1.[CH3:16][Si:17]([C:20]#[CH:21])([CH3:19])[CH3:18]>C(N(CC)CC)C.[Pd](Cl)Cl.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[CH3:1][C:2]1([CH3:15])[CH2:11][C:10]([CH3:13])([CH3:12])[C:9]2[C:4](=[CH:5][C:6]([C:21]#[C:20][Si:17]([CH3:19])([CH3:18])[CH3:16])=[CH:7][CH:8]=2)[O:3]1

Participants

Conditions

Temperature: 60 °C

Procedure

A solution of 2 g (7.4 mmol) of 2,2,4,4 tetramethyl-7-bromochroman (Compound 42) and 3.63 g (37.0 mmol) of trimethylsilylacetylene in 5 ml of triethylamine was placed in a heavy walled glass tube and degassed under nitrogen. The mixture was then treated, under nitrogen, with 130 mg (0.6826 mmol) of cuprous iodide and 260 mg (0.3704 mmol) of bis (triphenyl phosphine) palladium (II) chloride. The reaction mixture was degassed again and placed under nitrogen and the tube was sealed. The mixture was heated to 60 degrees C. for 24 hours and then cooled to room temperature and filtered through celite. The solvent was removed in vacuo and the residue purified by flash column chromatography (silica; 2% ethyl acetate/hexane) to give the title compound as a pale yellow solid.

Workup

customdegassed under nitrogen
customThe reaction mixture was degassed again
customthe tube was sealed
temperaturecooled to room temperature
filtrationfiltered through celite
customThe solvent was removed in vacuo
customthe residue purified by flash column chromatography (silica; 2% ethyl acetate/hexane)

Sources & evidence

ORD record: ord-952368d81c944e21929a71ff0ea79403
Source dataset: uspto-grants-1994_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05346895

Reaction notes

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