Titanium containing periodic mesoporous organosilica as an efficient catalyst for the epoxidation of alkenes
A new class of titanium containing organic–inorganic hybrid periodic mesoporous organosilica (Ti-LHMS-3) has been synthesized, which contain bis(propyliminomethyl)-phloroglucinol moiety in the pore-wall. The precursor organosilane compound is obtained by Vilsmeier–Haack formylation of phloroglucinol followed by its Schiff base condensation with 3-aminopropyl-triethoxysilane (APTES). The hybrid titananosilicate is finally obtained through in situ condensation of this as-prepared organosilane precursor and tetraethylorthosilicate with titanium isopropoxide under hydrothermal conditions. The material has been thoroughly characterized by using powder X-ray diffraction (PXRD), nitrogen adsorption/desorption, transmission and scanning electron microscopic, and FTIR spectroscopic tools. This hybrid mesoporous titanosilicate material showed excellent catalytic activity in the epoxidation of alkenes under mild liquid phase reaction conditions using tert-butyl hydroperoxide (TBHP) as the oxidant.
Graphical abstractNew titanium containing organic–inorganic hybrid periodic mesoporous organosilica has been synthesized and it showed efficient catalytic activity and selectivity in the epoxidation of olefins under liquid-phase conditions.Figure optionsDownload full-size imageDownload high-quality image (165 K)Download as PowerPoint slideHighlights► New titanium containing periodic mesoporous organosilica synthesized. ► Hybrid material contains bis(propyliminomethyl)-phloroglucinol moiety in the pore-wall. ► Ti-sites of hybrid titanosilicate have interaction with donor sites of the pore wall. ► Selective epoxidation of alkenes under mild liquid phase reaction conditions. ► tert-Butyl hydroperoxide (TBHP) as oxidant.
Journal: Catalysis Today - Volume 198, Issue 1, 30 December 2012, Pages 45–51