N-bromosuccinimide (3.2 gm, 18 mmol) and silver nitrate (252 mg, 1.5 mmol) were added to an alkyne (15 mmol) in a stirred solution of acetone (50 mL). The reaction mixture was stirred at room temperature for 3 hours. The reaction was quenched with cold water (50 mL) and extracted with n-pentane (100 mL x 3). The combined organic fractions were dried over anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (0.5% ethyl acetate in hexane solution) to give (2-bromoethynyl)triisopropylsilane.
(Bromoethynyl)triisopropylsilane is an important sterically hindered organosilicon protective agent, mainly used to protect various types of hydroxyl groups, especially in multifunctional hydroxyl compounds. It can be selectively protected and deprotected for the synthesis of nucleosides, nucleotides and sugar compounds.
(Bromoethynyl)triisopropylsilane could be used as an alkynylating reagen to synthesize the palladium-catalyzed primary amine-directed C(sp2)–H alkynylation of biaryl-2-amines[1].
[1] Jiang, Guangbin et al. “Palladium-catalyzed primary amine-directed regioselective mono- and di-alkynylation of biaryl-2-amines.” Chemical Communications 14 (2018): 1746–1749.
