Synthesis and characterization of mesoporous silica SBA-15 functionalized by mono-, di-, and tri-amine and its catalytic behavior towards Michael addition

This paper focuses on the preparation of amine-functionalized-mesoporous silica SBA-15 using the post-synthesis method. Several aminosilanes containing mono-, di- and tri-amine were tested to compare their structural/textural properties and catalytic performance. The functionalization of the catalysts was investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis TGA/DTA, Thermal programmed desorption (CO2-TPD and H2O-TPD) and zeta potential measurements. The modified materials were used as catalysts for Michael addition. Several parameters affecting the Michael addition were investigated such as catalyst amount, effect of amino groups, microwave irradiation and Michael acceptor using 1,3-dicarbonyl derivatives, β-ketoesters and β-ketoamides. The results show that these catalysts have interesting activities towards Michael addition, especially for 1,3-dicarbonyl derivatives and β-ketoesters. However, the use of β-ketoamides led to the spiranic compounds (Michael addition/Spirocyclization). The catalyst 4-SBA-15 was used in five consecutive experiments with slight loss of activity. This new method was developed for the preparation of Michael products under microwave in short reaction times. [Display omitted] •Functionalization of the mesoporous silica SBA-15 by mono-, di- and tri-amine using the post-synthesis method.•The use of CO2- and H2O-TPD to determine the basicity and the hydrophilic character of amino-functionalized-SBA-15.•Correlation between basicity, hydrophilic character and catalytic properties towards Michael Addition.•The application field and limitation of the amino-functionalized-mesoporous silica towards Michael Addition.