Pigulski Bartłomiej, Shoyama Kazutaka, Würthner Frank
Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074, Würzburg, Germany.
Angew Chem Int Ed Engl. 2020 Sep 7;59(37):15908-15912. doi: 10.1002/anie.202005376. Epub 2020 Jun 25.
The first planar π-extended azulene that retains aromaticity of odd-membered rings was synthesized by [3+3] peri-annulation of two naphthalene imides at both long-edge sides of azulene. Using bromination and subsequent nucleophilic substitution by methoxide and morpholine, selective functionalization of the π-extended azulene was achieved. Whilst these new azulenes can be regarded as isomers of terrylene bisimide they exhibit entirely different properties, which include very narrow optical and electrochemical gaps. DFT, TD-DFT, as well as nucleus-independent chemical shift calculations were applied to explain the structural and functional properties of these new π scaffolds. Furthermore, X-ray crystallography confirmed the planarity of the reported π-scaffolds and aromaticity of their azulene moiety.
通过在薁的两个长边侧对两个萘酰亚胺进行[3+3]周环化反应，合成了首个保留奇数元环芳香性的平面π-扩展薁。利用溴化反应以及随后的甲醇钠和吗啉亲核取代反应，实现了π-扩展薁的选择性功能化。虽然这些新型薁可被视为并四苯双酰亚胺的异构体，但它们表现出完全不同的性质，包括非常窄的光学和电化学能隙。采用密度泛函理论（DFT）、含时密度泛函理论（TD-DFT）以及独立于核的化学位移计算来解释这些新型π支架的结构和功能性质。此外，X射线晶体学证实了所报道的π支架的平面性及其薁部分的芳香性。
