Catalysis Letters, Vol.146, No.10, 1991-2000, 2016
N-Hydroxyphthalimide Immobilized on Poly(HEA-co-DVB) as Catalyst for Aerobic Oxidation Processes
In the present study, poly(HEA-co-DVB) was synthesized (loading of OH groups: 8.07 mmol OH/g, crosslinking degree: 6 % DVB) and used for N-hydroxyphthalimide (NHPI) immobilization via ester bond (NHPI loading: 2.06 mmol NHPI/g). The obtained polymeric support and poly(HEA-co-DVB)/NHPI catalyst were characterized by FT-IR and XPS spectroscopy, elemental analysis, thermogravimetry and particle size measurement. The novel polymer-supported NHPI catalyst was tested in aerobic oxidation of p-methoxytoluene and alpha-methylstyrene. The studied reactions were carried out in the presence of AIBN and/or Co(II) salt without solvent or in acetic acid as solvent. It was found that the obtained polymer-supported NHPI catalyst showed the best catalytic performance, which was attributed to a high content of accessible NHPI moieties. The recovery and recycling of the obtained HEA/DVB-NHPI was only possible in reactions proceeded in solvent-free conditions. [GRAPHICS] .