Metal‐Free Electrophilic Selenocyclization of 1,7‐Dienes: Synthesis of Selenium‐Containing Benzoxepines

ABSTRACT A K 2 S 2 O 8 ‑mediated electrophilic selenocyclization of 1,7‐dienes for the synthesis of selenium‐containing benzoxepines is developed. This method features good regioselectivity, broad substrate scope, and good functional‐group compatibility. Preliminary mechanistic studies reveal that this transformation may not undergo a free radical process.