Ruthenium Catalyzed Synthesis of N-Substituted Perhydroazepine Derivatives

Primary amines react with 1,6-hexanediol at 180 for 5 h under argon atmosphere in the presence of both O and to give N-substituted perhydroazepine derivatives in good yields. For aromatic amines such as anilines, O combined with showed the highest catalytic activity. On the other hand, in the reaction of aliphatic amines, O combined with showed the highest catalytic activity. These differences may be attributed to the difference in the basicity of these amines. Less basic aromatic amines may require less basic phosphines, while more basic aliphatic amines may require more basic phosphines as the ligands.