Recent Applications of Quinolinium Salts in the Synthesis of Annulated Heterocycles

[摘要] Quinoline derivatives are frequently found in natural products and biologically active compounds; however, construction of quinoline fused polyheterocycles is a challenging goal in synthetic organic chemistry. In this regard, quinolinium salts meet the demand to a great level, as they can be synthesized readily and employed effectively for rapid construction of the condensed heterocyclic core. The present review focuses on recent (2015–2021) applications of different quinolinium salts, which react with suitable partners to access diverse annulated products. Most of the reactions discussed here involve easily available starting materials, are operationally simple, offer high atom-efficiency, and are environmentally benign. Mechanistic aspects of representative transformations have also been highlighted to better understand the reaction pathways.

[学科分类] 精神健康和精神病学

[关键词] annulation;dearomative cyclization;heterocycles;mechanism;quinolinium salts