Abstract:
Mesoporous silica has been functionalized with 3-aminopropyl
triethoxy silane (3-APTES), followed by Schiff-base condensation
with 2-hydroxy-1-naphthaldehyde. Incorporation of copper and
nickel by covalent grafting onto the Schiff-base loaded
materials gives two heterogenized catalysts namely, Cu–Cat
and Ni-Cat, respectively. The materials have been characterized
by PXRD analyses, nitrogen sorption studies, TEM, TGA, FT-IR,
UV-visible and solid state MAS-NMR spectroscopy. The metal contents in the samples are estimated using ICP-AES studies.
Cu–Cat and Ni-Cat have been used as active catalyst in the
oxidation of various olefins e.g. styrene, a-methyl styrene,
cyclohexene, trans stilbene and cyclooctene in the presence of
tert-butyl hydroperoxide as the oxidant in acetonitrile under
mild conditions. Different products have been analyzed by gas
chromatography and gas chromatography-mass spectrometry.
The results show high conversion of the substrates, moderate
to good product selectivity and high TOFs of the reactions. The
catalysts are recycled without deteriorating their activities and
heterogeneous nature
