Diastereoselective Dearomatization of Chalcone‐Based Quinolinium Salts to Assemble Bridged Quinobenzazepine Polycycles

Quinobenzazepines are useful in medicinal chemistry, but their synthesis is very challenging. Herein, we designed and synthesized a range of multi-functional chalcone-based quinolinium salts; their synthetic application in the rapid and straightforward construction of quinobenzazepines was successfully explored. A wide range of oxa-bridged quinobenzazepine polycycles were afforded serendipitously through a dearomative cascade reaction of our newly developed quinolinium salts and acetylacetone. This synthetic strategy features high bond- and ring-forming efficiency and complete regio- and diastereoselective control. Herein, we designed and synthesized a range of multi-functional chalcone-based quinolinium salts and their synthetic application in the rapid and straightforward construction of oxa-bridged quinobenzazepine polycycles was successfully explored.+image