Synthesis, characterization and catalytic application of bifunctional catalyst: Al-MCM-41-NH2

A new type of acid-base bifunctional mesoporous catalyst is prepared by the modification of Al-MCM-41 surfaces with organic amine functional groups. The ratio of acidic and basic sites on the solid surface can be adjusted by varying the amount of 3-aminopropyl-triethoxysilane (APTES) in the reaction medium (toluene). The acid-base bifunctional catalysts show high catalytic activities and selectivities in one-pot deacetalization–Knoevenagel and deacetalization–nitroaldol (Henry) reactions. The cohabiting of acidic and basic sites in the materials acting in a cooperative way to catalyze nitroaldol (Henry) reaction is also demonstrated.

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► Acid-base bifunctional hexagonal mesoporous silica catalysts.
► Synthesized by simply grafting.
► Possess high activity for One-pot cascade reactions.
► An acid-base cooperative manner to catalyze nitroaldol reaction.