School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China.
Org Biomol Chem. 2021 Oct 14;19(39):8554-8558. doi: 10.1039/d1ob01674a.
A concise and environmentally friendly protocol was developed for the synthesis of 6-phenylbenzo[]quinolines. 6-Phenylbenzo[]quinolines were obtained in good yields irradiation of ()-2-phenyl-3-styrylpyridines with a 254 nm UV light (64 W) in EtOH under an argon atmosphere in the presence of TFA. The reaction is a dehydrogenative annulation reaction that proceeds through 6π-electrocyclization, a [1,5]-H shift, 1,3-enamine tautomerization, and elimination of a hydrogen molecule to afford 6-phenylbenzo[]quinolines. The described protocol not only avoids the usage of a transition metal catalyst and an oxidant but also has the advantages of high atom efficiency and mild reaction conditions.
开发了一种简洁且环保的方法，用于合成 6-苯基苯并[h]喹啉。在氩气气氛下，以三氟乙酸（TFA）为催化剂，通过 ()-2-苯基-3-苯乙烯基吡啶在 254nm 紫外光（64W）照射下于乙醇中反应，可得到收率良好的 6-苯基苯并[h]喹啉。该反应是一种脱氢环化反应，通过 6π-电环化、[1,5]-H 迁移、1,3-烯胺互变异构和消除一个氢分子，得到 6-苯基苯并[h]喹啉。所描述的方法不仅避免了使用过渡金属催化剂和氧化剂，而且具有原子经济性高和反应条件温和的优点。
