Synthesis of All Thiophene-Based [7]Helicenes and Trithienothiepines with Isomeric Location of Sulfur Atoms Based on Intramolecular Selectivity of Deprotonation
作者:Jinjian Wang、Guangxia Wang、Chunli Li、Yuexia Dong、Zhiying Ma、Hua Wang
DOI:10.1021/acs.joc.0c02629
日期:2021.3.19
Three unsymmetric thiophene-based [7]helicenes, namely, endo-exo-UH-1, endo-top-UH-2, and exo-top-UH-3, with different isomeric locations of sulfur atoms in two terminal thiophene rings were efficiently synthesized using dithieno[2,3-b:3′,2′-d]thiophene (bb-DTT), dithieno[2,3-b:2′,3′-d]thiophene (bt-DTT), and dithieno[2,3-b:3′,4′-d]thiophene (bs-DTT) as building blocks via Suzuki cross-coupling and
三个非对称噻吩基[7] helicenes,即,内切-外- UH-1 ,内切-顶部- UH-2 ,和外切-顶部- UH-3 ,具有硫原子的不同的异构体的位置在两个末端噻吩环是使用dithieno [2,3- b:3',2'- d ]噻吩(bb - DTT),dithieno [2,3- b:2',3'- d ]噻吩(bt - DTT)有效合成dithieno [2,3- b:3',4'- d ]噻吩(bs - DTT)作为通过Suzuki交叉偶联和分子内环化反应的构建基块。除了这些外消旋的[7]螺旋烯,在分子内环化过程中同时获得了两个新的杂环异构体,即三噻吩并噻吩类化合物TTTP-1和TTTP-2。两种新型的双DTT脱质子和用于合成目标化合物的环化反应显示出高选择性,并能高效构建UH和TTTP。X射线晶体学分析表明,UH具有典型的螺旋分子结构。内-端的两个末端噻吩环中硫原子的异构位置exo