Benzene, 1-bromo-3-iodo- → ((3-Bromophenyl)ethynyl)trimethylsilane

Beteiligte Stoffe

Reaktionsschritte

To a solution of m-bromoiodobenzene (25.0 g. 881.1 mmol) in diisopropylamine (500 ml), there were added bis(triphenylphosphine)palladium dichloride (1.24 g. 1.80 mmol) and copper (I) iodide (1.24 g, 2.03 mmol). The solution was degassed via a rapid stream of argon, and trimethylsilylacetylene (9.51 g, 97.0 mmol) was added over a period of 15 min. The reaction mixture was stirred at room temperature until G.C. analysis indicated the disappearance of starting material (2 h). The reaction mixture was cooled to room temperature and filtered to remove salts. The filtrate was concentrated in vacuo, and the oily residue was taken up in dichloromethane. The solution was washed with an aqueous 5% HCl solution (2×200 ml), water (2×200 ml) and brine (1×200 ml). The combined organic layers were dried (MgSO4) and the solvent removed in vacuo yielding the crude product as a yellow oil. The liquid chromatographed from silica gel in pentane. Elution with pentane gave the product (1b) (20.59 g, 91%) as a clear liquid: bp 81°-82° C., 1H NMR (200 MHz, CDCl3) c 0.30 (s), 7.23(m).

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