Novel Synthesis of Azepine Derivatives via Copper-Mediated Cyclization of 2-Aza-hepta-2,4-dien-6-ynyl Anions. Intramolecular Addition of Organocopper Centers to the C−C Triple Bond

Deprotonation of alkynyl imines 1 with LDA at low temperature and subsequent transmetalation with copper thiophenolate gives the annulated azepines 11a−i in 41−73% yield after aqueous workup. The key step of the reaction is a copper-mediated intramolecular nucleophilic attack at the triple bond.