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

Abstract 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.