Synthesis, Characterization and Application of Poly(4-Methyl Vinylpyridinium Hydroxide)/SBA-15 Composite as a Highly Active Heterogeneous Basic Catalyst for the Knoevenagel Reaction

摘要

In this paper poly (4-methyl vinylpyridinium hydroxide)/SBA-15 composite was prepared as a highly efficient heterogeneous basic catalyst by in situ polymerization method for the first time. It was characterized by XRD, FT-IR, BET, TGA, SEM and back titration using NaOH. This catalyst exhibited the excellent catalytic activities for the Knoevenagel condensation of various aldehydes with ethyl cyanoacetate. Over this catalyst, a,P-unsaturated carbonyl compounds were obtained in the reasonable yield at 95 °C in 10 - 30 min in H2O as a solvent with a 100% selectivity to the condensation products. Catalyst could be easily recycled after the reaction and it could be reused without the significant loss of activity/selectivity performance. No by-product formation, high yields, short reaction times, mild reaction conditions and operational simplicity with reusability of the catalyst were the salient features of the present synthetic protocol. Presence of H2O as a solvent was also recognized as a "green method".