Institute of Transformative Bio-Molecules (WPI-ITbM) , Nagoya University , Chikusa, Nagoya 464-8602 , Japan.
Graduate School of Science , Nagoya University , Chikusa, Nagoya 464-8602 , Japan.
J Am Chem Soc. 2020 Feb 12;142(6):3246-3253. doi: 10.1021/jacs.9b13549. Epub 2020 Feb 3.
The synthesis, structures, and properties of highly twisted, nonplanar aromatic macrocycles are described. These macrocycles with an approximately 90° twist angle were synthesized by an effective synthetic approach through a quadruple Suzuki-Miyaura coupling of 4,5-bisarylphenanthrene, a novel axially chiral nonplanar building block. By varying the cross-coupling partner as the spacer, a family of twisted macrocycles was synthesized, allowing for a systematic study of the effect of the spacer on macrocycle shape and photophysical properties. For example, a unique macrocyclic aggregation-induced emission (AIE) emitter with double tetraphenylethylene units as the spacers was readily synthesized. Furthermore, attributed to its conformationally restricted twisted structure, a 3,6-disubstituted-1,8-naphthalimide-incorporated macrocycle showed remarkable solvatofluorochromism with high fluorescence quantum yields. The excellent conformational stability of these macrocycles further enabled complete enantiomeric resolution and characterization. The racemization barrier of macrocycle was determined experimentally and supported by DFT calculations.
本文描述了高度扭曲、非平面芳香大环的合成、结构和性质。这些大环具有约 90°的扭转角，通过 4,5-双芳基菲的四重 Suzuki-Miyaura 偶联反应，使用一种新颖的轴向手性非平面砌块，以有效的合成方法合成。通过改变交叉偶联伙伴作为间隔物，合成了一系列扭曲的大环，允许系统地研究间隔物对大环形状和光物理性质的影响。例如，很容易合成具有双四苯乙烯单元作为间隔物的独特大环聚集诱导发射（AIE）发射器。此外，由于其受限的构象扭曲结构，含有 3,6-二取代-1,8-萘二甲酰亚胺的大环表现出显著的溶剂致变色，具有高荧光量子产率。这些大环的优异构象稳定性进一步实现了完全的对映体拆分和表征。大环的外消旋化势垒通过实验确定，并得到 DFT 计算的支持。
