The immobilization of 2,2,6,6-tetramethyl piperidine nitroxide (TEMPO) on cross-linked polystyrene (CPS) microspheres was realized via Friedel-Crafts acylation reaction and nucleophilic substitution reaction, and the heterogeneous catalyst microspheres TEMPO/CPS were obtained successfully. The chemical structure and morphology of TEMPO/CPS microspheres were characterized. The effects of different factors on the Friedel-Crafts acylation reaction between chlorobutyryl chloride (CBC) and CPS microspheres were examined, and the reaction conditions were optimized. Finally, a co-catalyst system was constructed by TEMPO/CPS and Fe(NO3)3, which was used in the oxidation reaction processes of cinnamyl alcohol as a primary alcohol and 1-phenethyl alcohol as a secondary alcohol with molecular oxygen as oxidant, respectively. The results show that for the Friedel-Crafts acylation reaction between CBC and CPS microspheres, the optimum Lewis acid catalyst is AlCl3, and the suitable solvent chloroform. During the reaction process, the additional cross-linking reaction occurs, which will weaken the strength of the microspheres. The Friedel-Crafts acylation reaction should be carried out at 75℃ and the reaction time should be 5 h. The co-catalyst system of TEMPO/CPS and Fe(NO3)3 possesses high catalytic activity, and under the conditions of lower temperature and ordinary pressure of oxygen, it can make 1-phenethyl alcohol highly effectively transform into acetophenone (1-phenethyl alcohol conversion rate of 88% at 75℃ for 24 h) and cinnamyl alcohol into cinnamic aldehyde.
DONG Ting-ting BI Cong-cong GAO Bao-jiao
. Preparation of TEMPO Immobilized on CPS Microspheres and Its Catalytic Oxidation Activity in Oxidation of Alcohols by Molecular Oxygen[J]. The Chinese Journal of Process Engineering, 2015
, 15(4)
: 677
-682
.
DOI: 10.12034/j.issn.1009-606X.215205