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 dezacetalization-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. (c) 2011 Elsevier B.V. All rights reserved.