Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan.
Org Lett. 2013 Jul 19;15(14):3522-5. doi: 10.1021/ol401125f. Epub 2013 Jul 9.
The design and synthesis of a new planar cyclooctatetraene (COT) with protons directly connected to the COT ring was attained by monoannelation with dithieno[3,4-b:3',4'-d]thiophene. The planar structure of the COT core was unambiguously confirmed by X-ray crystallography. The magnetic antiaromaticity of the COT core was found to be higher than that of the previously synthesized planar COTs with olefinic protons, according to the results of (1)H NMR and absorption spectra as well as NICS calculations.
通过与二噻吩[3,4-b:3',4'-d]噻吩的单环化反应，成功设计并合成了一种新型的具有直接与 COT 环相连的质子的平面环辛四烯（COT）。通过 X 射线晶体学明确证实了 COT 核心的平面结构。根据（1）H NMR 和吸收光谱以及 NICS 计算的结果，发现 COT 核心的反磁性芳香性高于先前合成的具有烯烃质子的平面 COT。
