Chlorodimethylvinylsilane

Experimental procedure: To a solution of 6-phenyl-2-hexyn-1-ol (1, 2.00 g, 11.5 mmol) in THF (50 mL) is added imidazole (1.56 g, 23.0 mmol) and chlorodimethylvinylsilane (3.11 mL, 23.0 mmol) at room temperature. After stirred for 1.5 h at that temperature, the mixture is filtered through a pad of Celite, and the filtrate is concentrated in vacuo. The residue is diluted with hexane. Precipitated imidazole hydrochloride is removed completely by filtration through a pad of Celite. The filtrate is concentrated in vacuo to afford 2.90 g (98%) of silyl ether 2 as a colorless oil. This crude product is used in the next step without further purification. To a solution of 2 (258 mg, 1.00 mmol) and triisopropylsilane (205 µL, 1.00 mmol) are added Karstedt Catalyst (2% in xylene, 19.8 µL, 0.002 mmol) at room temperature. This mixture is warmed to 80 °C, and stirred for 1 h at that temperature. After cooling to room temperature, THF (10 mL) and TBAF (1.0 mol/L in THF, 1.20 mL, 1.2 mmol) are added to the reaction mixture and stirred for 15 min at that temperature. The solution is concentrated in vacuo, and then the residue is purified by silica gel chromatography (hexane:Et₂O = 10:1) to afford 313 mg (94%) of silylalkene 3 as a colorless oil.