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. [reaction: see text]
Lyaskovskyy
Volodymyr
V
Organisch-Chemisches Institut der Westfälischen Wilhelms-Universität Münster, D-48149 Münster, Germany.
Bergander
Klaus
K
Fröhlich
Roland
R
Würthwein
Ernst-Ulrich
EU
D000480:Alkynes / Q000737:chemistry*; D000838:Anions; D001381:Azepines / Q000138:chemical synthesis*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003500:Cyclization; D009942:Organometallic Compounds / Q000737:chemistry*; D011522:Protons; D013237:Stereoisomerism
D000480:Alkynes; D000838:Anions; D001381:Azepines; D009942:Organometallic Compounds; D011522:Protons; D002244:Carbon; D003300:Copper