Construction of Terminal Conjugated Enynes: Cu-Mediated Cross-Coupling Reaction of Alkenyldialkylborane with (Trimethylsilyl)ethynyl Bromide
作者:Masayuki Hoshi、Noritsugu Kawamura、Kazuya Shirakawa
DOI:10.1055/s-2006-942373
日期:2006.6
cross-coupling reaction of (Z)-1-(trimethylsilyl)alk-1-enyldicyclohexylborane with (trimethylsilyl)ethynyl bromide proceeds in the presence of a small amount of copper(I) iodide and aqueous sodium hydroxide under extremely mild conditions to afford (Z)-l,3-bis(trimethylsilyl)alk-3-en-l-yne with high regio- and stereoselectivity. In addition, treatment of the resulting product with sodium methoxide (1 M) leads
(E)- 和 (Z)-alk-1-enyl-dialkylborane 与 (三甲基甲硅烷基) 乙炔基溴的交叉偶联反应在催化量的乙酰丙酮铜 (II) 和碱的存在下在极其温和的条件下进行提供具有末端碳-碳三键的共轭烯炔。使用甲醇钠 (1 M) 作为碱不仅可以产生交叉偶联,而且还可以进行脱甲硅烷化,从而得到 (E)- 和 (Z)-alk-3-en-1-ynes,而氢氧化锂一水合物则同时得到 (E)-和 (Z)-alk-3-en-1-ynes。 E)- 和 (Z)-1-(trimethylsilyl)alk-3-en-1-ynes 具有高区域和立体选择性。另一方面,(Z)-1-(三甲基甲硅烷基)烷-1-烯基二环己基硼烷与(三甲基甲硅烷基)乙炔基溴的交叉偶联反应在少量碘化铜(I)和氢氧化钠水溶液的存在下在极其温和的条件下进行,得到(Z)-l,3-bis(trimethylsilyl)alk-3-e