Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, Koriyama 963-8642, Fukushima, Japan.
Department of Material Science, Graduate School of Science and Technology, Shinshu University, Matsumoto 390-8621, Nagano, Japan.
Chem Commun (Camb). 2023 Mar 16;59(23):3447-3450. doi: 10.1039/d3cc00373f.
Dibenzofurans featuring a 2,2'-biazulene framework were prepared in good yields by Brønsted acid-promoted annulation of 2,3-di(1-azulenyl)benzofurans in 100% HPO. NMR, UV-Vis, and fluorescence spectroscopies were used to investigate the structural and optical properties of the products prepared. Remarkably, the annulated products exhibited fluorescence, with the longest wavelength of azulene derivatives reported to date, which extended into the near-infrared region under acidic conditions.
具有 2,2'-联氮杂芴骨架的二苯并呋喃通过 Brønsted 酸促进的 2,3-二（1-薁基）苯并呋喃在 100%HPO 中的环化反应以良好的产率制备。使用 NMR、UV-Vis 和荧光光谱研究了制备的产物的结构和光学性质。值得注意的是，稠合产物表现出荧光，其最长波长为迄今为止报道的薁衍生物，在酸性条件下延伸到近红外区域。
