Piperidine → 2-[(Trimethylsilyl)ethynyl]thiophene

HRID 1837951Notes

Reaction equation

HRID 1837951 reaction equation
N1CCCCC1.Br[C:8]1[S:9][CH:10]=[CH:11][CH:12]=1.[CH3:13][Si:14]([C:17]#[CH:18])([CH3:16])[CH3:15]>CCCCC.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.[Cu]I.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[S:9]1[CH:10]=[CH:11][CH:12]=[C:8]1[C:18]#[C:17][Si:14]([CH3:16])([CH3:15])[CH3:13]

Participants

9

Reactant 3

HCID 8082PiperidineHCID 138512-BromothiopheneHCID 66111Trimethylsilylacetylene

Product 1

HCID 5968702-[(Trimethylsilyl)ethynyl]thiopheneYield 79%

Reagents, catalysts & solvents 5

HCID 11776TriphenylphosphineCatalystHCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolventHCID 8003PentaneSolvent

Procedure

To a mixture of piperidine (10 mL, 93.9 mmol), 2-bromothiophene (3.21 g, 19.7 mmol), and (trimethylsilyl)acetylene (2.13 g, 21.7 mmol) was added Pd(PPh3)4 (0.03 g, 0.026 mmol), followed by CuI (0.01 g, 0.05 mmol) and PPh3 (0.015 g, 0.057 mmol). The reaction mixture was heated at the reflux temperature for 45 min., and was allowed to cool to room temperature. The resulting dark brown slurry was diluted with pentane (20 mL) and water (20 mL) and the aqueous layer was extracted with pentane (2×20 mL). The organic layers were washed with a saturated NH4Cl solution (4 mL) and a 3M HCl solution (4 mL), dried (MgSO4) and concentrated under reduced pressure to give 2-(2-thienyl)-1-trimethylsilylacetylene (2.79 g, 79%) as a reddish brown oil: GC-MS m/z (rel abundance) 180 (M+, 30%); 1H NMR (CDCl3) δ 0.15 (s, 9H), 6.79 (m, 1H), 7.15 (m, 2H).

Workup

  1. temperatureThe reaction mixture was heated at the reflux temperature for 45 min.
  2. extractionthe aqueous layer was extracted with pentane (2×20 mL)
  3. washThe organic layers were washed with a saturated NH4Cl solution (4 mL)
  4. dry with materiala 3M HCl solution (4 mL), dried (MgSO4)
  5. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-47db63da80934caf9e456e4e9eb8f17d
Source dataset
uspto-grants-2004_08
Patent number
US06784167B2

Reaction notes

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