Pd-Catalyzed Dual C–H Activation/Cyclization: Convergent and Divergent Synthesis of 1-Azahelicenes

作者：Yixin Xu, Yuqing Liang, Wenru Liu, Huikang Fang, Hongkun Li, Shun‐Jun Ji, Zhong‐Jian Cai · 发表于：Organic Letters · 年份：2024 · DOI：10.1021/acs.orglett.4c03136 · 被引用次数：9 · 研究领域：Catalytic C–H Functionalization Methods、Synthesis of Indole Derivatives、Cyclopropane Reaction Mechanisms

Herein, we report a convergent synthesis of 1-azahelicenes using easily available quinoline derivatives and cyclic diaryliodonium salts as starting materials. This reaction undergoes a palladium-catalyzed dual C–H activation/cyclization process to give facile access to a wide range of 1-aza[5]helicenes and 1-aza[6]helicenes with abundant functional groups (including F, Cl, Br, I, CF 3, SeR, SR, and heteroaryl) in moderate to excellent yields, thereby providing new opportunities to fine-tune the properties of the helicene backbone. In addition, the obtained products could be further transformed into helicene-based Lewis base catalysts and redox switch materials easily. Notably, one selected 1-azahelicene shined bright yellow light by aggregation. These features enlarge the chemical space of 1-azahelicenes and inspire further utilization in other areas of research.