Unusual Formation of Cyclopenta[<i>b</i>]indoles from 3-Indolylmethanols and Alkynes
作者:Soniya Gandhi、Beeraiah Baire
DOI:10.1021/acs.joc.8b03027
日期:2019.4.5
suitable for this transformation. Similarly, N-Ts and N-Boc groups were compatible with reaction conditions, whereas N-Ac and N-Tf failed to undergo this reaction. Isolation of vinyl chloride intermediate suggested the involvement of a vinylic carbocation intermediate. A mechanism has been proposed involving a ring-opening–ring-closing cascade followed by a 1,3-indole migration process via a spirocyclobutene
已经报道了由3-吲哚基甲醇和炔烃酸促进的环戊[ b ]吲哚骨架的合成。整个变换表示通过重新排列而形成的正式[3 + 2]圆环。该方案对甲醇底物和炔烃显示出良好的通用性,并允许生成结构多样的环戊[ b ]吲哚。发现末端炔烃,二烷基取代的内部炔烃和具有电子不足的取代基的炔烃不适合该转化。同样,N -Ts和N -Boc基团与反应条件兼容,而N -Ac和N-Tf未能进行此反应。氯乙烯中间体的分离表明涉及乙烯基碳阳离子中间体。已经提出了一种机制,包括开环-闭环级联反应,然后通过螺环丁烯中间体进行1,3-吲哚迁移过程。