Syntheses and Properties of Strained Polycyclic Compounds

近年来，设计和制造具有特殊结构、电子和光学性能的新型富碳材料已成为人们关注的焦点。然而，尽管具有迷人的结构特征，π共轭的具有圆柱形结构的富碳大环仍然是一个合成挑战，尽管已经报道了一些尝试制备相关的带状分子。在本研究中，我们研究了第一个[4_6]对环苯十二烷衍生物的合成和表征，其中6个对苯和丁二炔单元交替连接，形成一个高度不饱和的圆柱形π共轭体系。本方法的一个关键特点是利用杜瓦苯作为角对苯合成物。因此，[4_6]对环番十二烷衍生物是由相应的六（杜瓦苯）化合物光化学合成的，是一种高应变但可分离的化合物。目前的结果清楚地表明，我们的杜瓦苯构建块方法在构建难以从平面苯衍生物制备的应变苯基大环方面具有很高的合成潜力。

Recently much attention has been focused on the design and construction of novel carbon-rich materials with unusual structural, electronic and optical properties. Despite the fascinating structural features, however, π-conjugated carbon-rich macrocycles with a cylindrical structre still remain as a synthetic challenge, although several attempts to prepare related belt-shaped molecules have been reported. In this study we examined the synthesis and characterization of the first [4_6]paracyclophanedodecayne derivative, in which six p-phenylene and butadiyne units are connected alternatively to form a highly unsaturated cylindrical π-conjugated system. A key feature in the present approach is exploitation of a Dewar benzene as an angular p-phenylene synthon. Thus, [4_6]paracyclophanedodecayne derivative has been photochemically generated from the corresponding hexakis(Dewar benzene) compound as a highly strained but isolable compound. The present results clearly demonstrate the high synthetic potential of our Dewar benzene building block approach for the construction of strained phenylene macrocycles that are difficult to prepare from planar benzene derivatives.