Cytosine-functionalized SBA-15 mesoporous nanomaterials: Synthesis, characterization and catalytic applications

Periodic mesoporous silica functionalized by cytosine (Cyt@SBA-15) was prepared from Cytosine-chloropropyltriethoxysilane and tetraethoxysilane as precursors by a sol-gel method. The surface area and pore volume of Cyt@SBA-15 were 490 m(2)/g and 0.77 cm(3)/g. Due to their porous structure and active functional groups of cytosine on the pore of the hybrid material (Cyt@SBA-15), its catalytic performance was studied in the Knoevenagel condensation of aldehydes and ketones with malononitrile to alpha, beta-unsaturated dicyanides in the presence of ethanol as solvent. The catalyst exhibited an excellent activity and selectivity toward the final condensation product under mild reaction conditions. Furthermore, the catalyst could be recovered and reused several times without any significant loss in either activity or product selectivity. (C) 2017 Elsevier Inc. All rights reserved.