Synthesis of Phenethylamine‐Azulene Conjugates Enabled by Regioselective Ring Opening of Aziridines

Abstract The BF 3 ⋅OEt 2 ‐catalyzed reaction of azulene with N ‐protected aziridines represents a general, efficient (up to 91% yield) and regioselective approach to phenethylamine‐azulene conjugates. Stereochemical studies and DFT calculations lend support to a concerted S N 2‐type mechanism governing the ring‐opening of the aziridine.