posted on 2016-10-02, 18:29authored byAna P. C. Ribeiro, Luísa M. D. R. S. Martins, Maxim L. Kuznetsov, Armando J. L. Pombeiro
For the first time, microwave (MW)
irradiation was successfully applied to peroxidative cyclohexane oxidation
catalyzed by a C-scorpionate complex, [FeCl2(Tpm)] (1; Tpm = hydrotris(pyrazol-1-yl)methane), providing a highly
selective and fast eco-friendly procedure to produce a KA (cyclohexanol
+ cyclohexanone) oil mixture (up to ca. 100% selectivity) with 28%
yield in 1 h at 50 °C in MeCN. Water, organics, and ionic liquids
(ILs, [bmim][N(CN)2] and [bmim][BF4]) were used
as solvents, and their interactions with 1 were determined
by DFT calculations. The possibility to recycle and reuse 1 (up to nine consecutive cycles) without loss of activity is also
observed for the IL [bmim][BF4]. Moreover, higher catalytic
activities under additive-free conditions are obtained with the ILs
in comparison to those with the other solvents. Tuning the alcohol/ketone
selectivity is also possible by choosing the appropriate IL solvent.