2009/05/31 by Gopal S. Mishra, Telma F. S. Silva, Luísa M. D. R. S. Martins +1 · 1 citation
Chemistry · #Metal-Catalyzed Oxygenation Mechanisms #Oxidative Organic Chemistry Reactions #Vanadium and Halogenation Chemistry
paper · pdf · doi:10.1351/pac-con-08-10-08
openalex publication_date 2009/05/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The V-scorpionate vanadium complexes [VCl 3 HC(pz) 3 ] (pz = pyrazolyl) and [VCl 3 SO 3 C(pz) 3 ] catalyze cyclohexane oxidation with dioxygen, to cyclohexanol (the main product) and cyclohexanone, under solvent-free conditions. [VCl 3 HC(pz) 3 ] provides the best activity (13 % conversion into the ketone and alcohol, with high selectivity, at the O 2 pressure of 15 atm, at 140 ºC, 18 h reaction time). The reaction is further promoted (to 15 % conversion) by pyrazinecarboxylic acid (PCA). The use of C- or O-radical traps supports the involvement of a free-radical reaction mechanism. Several reaction parameters have been varied in a systematic study, directed toward optimization of the process.