A new method for the synthesis of conjugated polyenes containing up to eight double bonds with all-E configuration is reported. The procedure is based upon a homocoupling reaction of dienyl-, trienyl-, or tetraenylsilanes, promoted by PdCl(2) in methanol and in the presence of LiCl and CuCl(2). Configurational and conformational assignments were rigorously made on the basis of NMR spectra. The compounds
报道了一种新的合成共轭多烯的新方法,该共轭多烯含有多达8个全E构型的双键。该程序基于PdCl(2)在
甲醇中以及在LiCl和CuCl(2)的存在下,二烯基,
三烯基或四烯基
硅烷的均偶联反应。在NMR光谱的基础上严格进行构型和构象分配。获得的化合物代表了一类新颖的有趣的对称取代的多烯,具有潜在的光学和电光学特性。通过改变溶剂,可以将均偶联过程切换为甲
硅烷基取代的末端双键的卤化反应,从而导致聚烯基卤化物。