Trimethylsilylacetylene → 2,2,4,4-Tetramethyl-6-trimethylsilylethynylthiochroman

HRID 373408Notes

Reaction equation

HRID 373408 reaction equation
[CH3:1][C:2]1([CH3:15])[CH2:11][C:10]([CH3:13])([CH3:12])[C:9]2[C:4](=[CH:5][CH:6]=[C:7](Br)[CH:8]=2)[S: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][CH:6]=[C:7]([C:21]#[C:20][Si:17]([CH3:19])([CH3:18])[CH3:16])[CH:8]=2)[S:3]1

Participants

5

Reactant 2

HCID 66111Trimethylsilylacetylene2×HCID 156611232,2,4,4-Tetramethyl-6-bromothiochroman2×

Product 1

HCID 156611272,2,4,4-Tetramethyl-6-trimethylsilylethynylthiochroman

Reagents, catalysts & solvents 2

HCID 6102075Dichlorobis(triphenylphosphine)palladiumCatalyst2×HCID 8471TriethylamineSolvent

Conditions

Temperature
100 °C

Procedure

A solution of 600 mg (2.11 mmol) of 2,2,4,4-tetramethyl-6-bromothiochroman (Compound 33) in 1.5 ml of triethylamine was placed in a heavy-walled tube and degassed and then treated under argon with 1.4 g (14.3 mmol) of trimethylsilylacetylene and a powdered mixture of 75 mg (0.39 mmol) of cuprous iodide and 150 mg (0.21 mmol) of bis(triphenylphosphine) palladium (II) chloride. The reaction mixture was degassed again, then placed under argon and the tube was sealed. The mixture was heated at 100 degrees C. for 24 h, allowed to cool to room temperature and then treated with a further 1.4 g (14.3 mmol) of trimethylsilylacetylene and a powdered mixture of 75 mg (0.39 mmol) of cuprous iodide and 150 mg (0.21 mmol) of bis(triphenylphosphine) palladium (II) chloride. The mixture was then degassed, placed under argon and then heated in the sealed tube at 100 degrees C. for 96 h. The mixture was cooled to room temperature and extracted with 3×10 ml of ether. The organic extracts were combined, washed successively with 25 ml of water and 25 ml of saturated sodium chloride solution and then dried (MgSO4). The solvent was removed in vacuo and the residue purified by flash chromatography (silica; hexanes followed by 3% ethyl acetate in hexanes) to give the title compound as a yellow, crystalline solid. PMR (CDCl3): & 0.23 (9H, s), 1.36 (6H, s), 1.39 (6H, s), 1.94 (2H, s), 7.17 (1H, dd, J~8.2 Hz, 1.8 Hz), 7.25 (1H, d, J~1.8 Hz), 7.30 (1H, d, J~8.2 Hz). MS exact mass, m/1 302.1519 (calcd. for C18H26S Si, 382.1524).

Workup

  1. customdegassed
  2. customThe reaction mixture was degassed again
  3. customthe tube was sealed
  4. temperatureto cool to room temperature
  5. customThe mixture was then degassed
  6. temperatureheated in the sealed tube at 100 degrees C
  7. waitfor 96 h
  8. temperatureThe mixture was cooled to room temperature
  9. extractionextracted with 3×10 ml of ether
  10. washwashed successively with 25 ml of water and 25 ml of saturated sodium chloride solution
  11. dry with materialdried (MgSO4)
  12. customThe solvent was removed in vacuo
  13. customthe residue purified by flash chromatography (silica; hexanes followed by 3% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-c82a4db0d1a14dd8ae2a592abe0ca774
Source dataset
uspto-grants-1992_11
Patent number
US05162546

Reaction notes

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