Adachi Kohei, Nogami Juntaro, Hashizume Daisuke, Tauchi Daiki, Hasegawa Masashi, Tanaka Ken
Department of Chemical Science and Engineering, Institute of Science Tokyo, O-okayama, Meguro-ku, Tokyo, 152-8550, Japan.
Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan.
Angew Chem Int Ed Engl. 2025 May 26;64(22):e202502764. doi: 10.1002/anie.202502764. Epub 2025 Apr 7.
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.
手性分子的螺旋组装体能够将微观的单分子手性传递至宏观的超分子手性，增强各种手性性质。除了常见的螺旋柱状螺旋组装体外，在具有多个与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体。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。在此，我们报道了通过铑催化十二炔与两个柔性联苯单元的连续四次分子内[2 + 2 + 2]环加成反应，对映选择性和非对映选择性合成具有稳定螺旋手性的八面体[10]环亚苯。带有乙基和甲基侧链的手性八面体[10]环亚苯由于CH-π和CH-O相互作用在晶体中呈现螺旋楼梯状单螺旋组装体，并且在溶液中具有良好的圆偏振发光性质。还报道了连续四次[2 + 2 + 2]环加成反应的对映和非对映决定步骤的实验验证。
