FeCl3–diorganyl dichalcogenides promoted cyclization of 2-organochalcogen-3-alkynylthiophenes: synthesis of chalcogenophene[2,3-b]thiophenes
作者:André L. Stein、Filipe N. Bilheri、Alisson R. Rosário、Gilson Zeni
DOI:10.1039/c3ob27498e
日期:——
We report here our results on the FeCl3âdiorganyl dichalcogenides intramolecular cyclization of 2-organochalcogen-3-alkynylthiophenes. The cyclization reaction proceeded cleanly under mild reaction conditions giving the (S)-Se-, (S)-S- and (S)-Te-heterocycles in good yields. In addition, the obtained chalcogenophenes were readily transformed into more complex products using the palladium cross-coupling reaction with boronic acids. Conversely, using a metalâhalogen exchange reaction with n-BuLi, the chalcogenophenes produced the lithium-intermediate which was trapped with aldehyde furnishing the desired secondary alcohol in good yield.
我们在此报告关于FeCl3–二有机二硫醚对2-有机硫-3-炔基噻吩的分子内环化反应的结果。该环化反应在温和的反应条件下进行,反应过程顺利,产出了(S)-Se-、(S)-S-和(S)-Te-杂环,并且收率良好。此外,所得到的硫族噻吩可以通过与硼酸的钯交叉偶联反应方便地转化为更复杂的产品。相反,利用n-BuLi进行金属-卤素交换反应,硫族噻吩生成了锂中间体,该中间体与醛反应生成所需的二级醇,且收率良好。