Helix assemblies of chiral molecules can transfer microscopic unimolecular chirality to macroscopic supramolecular chirality, enhancing various chiral properties. In addition to the commonly observed spiral‐column‐like helix assembly, a small number of spiral‐stair‐like helix assemblies have also been reported in aromatic nanocarbons with multiple chirality‐related irregularities. However, they require separation of diastereomers and/or enantiomers or do not have stable chirality. Here, we report the enantio‐ and diastereoselective synthesis of figure‐eight [10]cyclophenylenes with stable helical chirality by the rhodium‐catalyzed four consecutive intramolecular [2+2+2] cycloadditions of dodecaynes with two flexible biphenyl units. The chiral figure‐eight [10]cyclophenylene with ethyl and methyl side chains exhibits the spiral‐stair‐like single helix assembly in the crystal due to CH–π and CH–O interactions and good CPL properties in solution. Experimental verification of the enantio‐ and diastereodetermining steps of four consecutive [2+2+2] cycloadditions is also reported.

中文翻译：

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对映体和非对映选择性合成以及 8 字形环苯的螺旋阶梯状单螺旋组装


手性分子的螺旋组装体可以将微观单分子手性转移到宏观超分子手性，从而增强各种手性特性。除了通常观察到的螺旋柱状螺旋组装体外，在具有多种手性相关不规则性的芳香族纳米碳中也报道了少量螺旋楼梯状螺旋组装。然而，它们需要分离非对映异构体和/或对映异构体，或者不具有稳定的手性。在这里，我们报道了通过铑催化的四连续分子内 [2+2+2] 环加成反应与两个柔性联苯单元合成具有稳定螺旋手性的 8 字形和非对映选择性合成具有稳定螺旋手性的 8 字形 [10] 环苯。由于 CH-π 和 CH-O 相互作用以及溶液中良好的 CPL 性能，具有乙基和甲基侧链的手性 8 字形 [10] 环苯在晶体中表现出螺旋阶梯状单螺旋组装。还报道了四个连续 [2+2+2] 环加成反应的对映体和非对映决定步骤的实验验证。