Trimethylsilylacetylene → HCID 12687364, compound

Participants

Reaction Steps

In Step II of FIG. 1, 4,4'-diiododiphenylmethane [Compound (2)] was then coupled with ethynyltrimethylsilane [Compound (3)] to form an end-protected bis(4-trimethylsilylethynylphenyl)methane [Compound (4)] by forming a solution comprising 8.40 g (20.0 mmoles) of 4,4'-diiododiphenylmethane and 2.50 g (25.5 mmoles) of ethynyltrimethylsilane in 150 ml of 2:1 triethylamine toluene deaerated with argon. This solution was subsequently treated with a catalyst mixture comprising 50 mg of dichlorobis(triphenylphosphine)palladium[II], 150 mg of triphenylphosphine and 50 mg of copper[I] iodide. The yellow solution thus obtained was stirred and warmed to 80°-90° C. over 1 hour and kept in this temperature range for 4 hours. A copious white precipitate was formed which was filtered off after cooling to 25° C. and diluting with 150 ml of ether. The yield of triethylamine hydroiodide [Compound (5)] was quantitative. The filtrate was concentrated to a thick oil, dissolved in 200 ml of ether and washed with 200 ml each of 10% aqueous hydrochloric acid, water, saturated aqueous sodium bicarbonate, and water again. The ethereal phase was dried over magnesium sulfate and concentrated to an oil which crystallized on standing. The solid was taken up in 100 ml of 1:1 hexane/dichloromethane and filtered through a bed of silica gel. The filtrate was evaporated down to half of the original volume and cooled at -78° C. to precipitate 7.20 g (20.0 mmoles; 100%) of a crystalline solid. Recrystallization from hexane yielded pure, lustrous crystals in 81% recovery: mp 110°-111° C.; IR(KBr) 2790 (strong, sharp, SiCH3), 2160 (strong, sharp, C≡C), 1505 (strong, sharp, C=C), 1250 (strong, sharp, SiCH3) and 840 cm-1 (very strong, broad, Si-C bending); NMR(CDCl3) δ 0.28 (s, 18H, SiCH3), 3.92 (s, 2H, CH2), 7.37 and 7.40 ppm (q, 8H, JAB =8.0 Hz, aromatic).

Provenance & Evidence