Biedermann P Ulrich, Agranat Israel
Organic Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem, Philadelphia Bldg. #201-205, Edmond J. Safra Campus, Jerusalem, 91904, Israel,
Top Curr Chem. 2014;350:177-277. doi: 10.1007/128_2014_534.
Bistricyclic aromatic enes (BAEs) and related polycyclic systems are a class of molecular materials that display a rich variety of conformations, dynamic stereochemistry and switchable chirality, color, and spectroscopic properties. This is due to the a subtle interplay of the inherent preference for planarity of aromatic systems and the competing necessity of non-planarity due to intramolecular overcrowding in the fjord regions built into the general molecular structure of BAEs. The conformational, dynamic, and spectroscopic properties may be designed and fine-tuned, e.g., by variation of the bridging groups X and Y, the overcrowding in the fjord regions, extensions of the aromatic system, or other modifications of the general BAE structure, based on the fundamental understanding of the structure-property relationships (SPR). The present review provides an analysis of the conformational spaces and the dynamic stereochemistry of overcrowded bistricyclic aromatic enes applying fundamental symmetry considerations. The symmetry analysis presented here allows deeper insight into the conformations, chirality, and the mechanisms of the dynamic stereochemistry, and will be instrumental in future computational studies.
双环芳烯（BAEs）及相关多环体系是一类分子材料，它们展现出丰富多样的构象、动态立体化学以及可切换的手性、颜色和光谱性质。这是由于芳香体系对平面性的固有偏好与因BAEs总体分子结构中峡湾区域内分子内过度拥挤导致的非平面性的竞争需求之间存在微妙的相互作用。基于对结构-性质关系（SPR）的基本理解，例如通过改变桥连基团X和Y、峡湾区域的过度拥挤情况、芳香体系的扩展或对BAE总体结构的其他修饰，可以设计和微调构象、动态和光谱性质。本综述运用基本对称考量对过度拥挤的双环芳烯的构象空间和动态立体化学进行了分析。此处呈现的对称分析能够更深入地洞察构象、手性以及动态立体化学的机制，并且将对未来的计算研究起到推动作用。
