Theoretical studies on copper-catalyzed arylation of nitrogen heterocycles from benzenediazonium acetate under ligand-free conditions

• Published in: Journal of organometallic chemistry Vol. 864; pp. 50 - 57
• Main Authors: Ahmad, Khalil, Chang, Chun-Ran, Li, Jun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2018
• Subjects: Catalytic mechanism; Copper-catalyzed; C─N cross coupling; DFT; Copper-catalyzed; DFT; Catalytic mechanism; C─N cross coupling
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/j.jorganchem.2018.01.006

The density functional theory (DFT) method was used to investigate the mechanism of ligand-free copper-catalyzed arylation of nitrogen heterocycles from benzenediazonium acetate. Two possible mechanisms, single electron transfer and oxidative addition/reductive elimination reaction mechanism were investigated for two possible Cu(I) complexes in the reaction solution. Complex 1 has an acetate and a pyrazole ligand coordinated to Cu(I), and complex 2 has two pyrazole ligands coordinated to Cu(I). Both Cu(I) complexes have sufficiently low activation energy barriers for oxidative addition/reductive elimination reactions. Activation energy barrier for single electron transfer reaction is significantly higher than oxidative addition/reductive elimination reaction. [Display omitted] •DFT study of Cu-catalyzed C-N coupling between benzenediazonium acetate and pyrazole.•Multiple pathways explored for oxidative addition/reductive elimination mechanism.•Exploration of outer and inner sphere single electron transfer reaction mechanisms.•Oxidative addition/reductive elimination mechanism has suitable activation energy.•Activation energy for single electron transfer mechanism is significantly higher.