Piperidine → 2-(Trimethylsilylethynyl)thiophene

Participants

Reaction Steps

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).

Provenance & Evidence