Titanium containing periodic mesoporous organosilica as an efficient catalyst for the epoxidation of alkenes

Abstract

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.