Direct synthesis of acid–base bifunctionalized hexagonal mesoporous silica and its catalytic activity in cascade reactions

A series of efficient acid–base bifunctionalized hexagonal mesoporous silica (HMS) catalysts contained aminopropyl and propanesulfonic acid have been synthesized through a simple co-condensation by protection of amino group. The results of small-angle XRD, TEM, and N2 adsorption–desorption measurements show that the resultant materials have mesoscopic structures. X-ray photoelectron spectroscopies, elemental analysis (EA), back titration, 29Si NMR and 13C NMR confirm that the organosiloxanes were condensed as a part of the silica framework. The resultant catalysts exhibit excellent acid-basic properties, which make them possess high activity for one-pot deacetalization–Knoevenagel and deacetalization–nitroaldol (Henry) reactions.

A series of efficient acid–base bifunctionalized hexagonal mesoporous silica (HMS) catalysts have been synthesized. The novel catalysts possess high activity for cascade reactions.Figure optionsDownload high-quality image (67 K)Download as PowerPoint slideResearch highlights
► Acid-base bifunctionalized hexagonal mesoporous silica catalysts.
► Synthesized through protection of amino group.
► Exhibit excellent acid-basic properties.
► Possess high activity for one-pot cascade reactions.