Synthesis of Polycyclic Arenes Composed of Four‑, Five‑, Six‑, and Eight-Membered Rings via an Unexpected Four-Membered Ring Formation Reaction

The synthesis of polycyclic arenes composed of four-,
five-, six-,
and eight-membered rings via an unexpected four-membered ring formation
reaction is reported. The carbonylation of an octalithiated tetraphenylene
yielded a tricarbonylated arene containing a four-membered ring or
a tetracarbonylated one, depending on the carbonyl reagents. The structures
were determined by X-ray crystallography, and their electronic properties
were examined by using absorption spectroscopy and cyclic voltammetry.
The antiaromaticity of the four-, five-, and eight-membered rings
of these compounds was studied by theoretical calculations.

本研究报告了通过一种意料之外的四个碳原子环形成反应，合成由四个、五个、六个和八个碳原子环组成的稠环芳烃的过程。八位取代的四苯基乙烯经过羰基化反应，产生了含有四个碳原子环的三羰基取代芳烃或四羰基取代芳烃，具体取决于羰基试剂。通过X射线晶体学确定了其结构，并利用吸收光谱学和循环伏安法对其电子性质进行了考察。通过理论计算研究了这些化合物中四个、五个和八个碳原子环的共轭反芳香性。