Imidazolium chloride immobilized SBA-15 as a heterogenized organocatalyst for solvent free Knoevenagel condensation using microwave

Heterogeneous organocatalyst, 1-methyl-3-[(3-triethoxysilyl) propyl] imidazolium chloride [MTESPImCl] immobilized SBA-15 (ILS) was synthesized by co-condensation method using microwave irradiation in which 1-methylimidazole (Im) was modified by organosilane (3-chloropropyl triethoxysilane). The ILS was thoroughly characterized by small angel XRD, N2 adsorption desorption isotherms, TEM, SEM, TGA and FT-IR. The ILS showed 2D hexagonal short channeled disk type mesostructure which can provide facile to-and-from diffusion of substrates and products with enhanced activity. This heterogenized organocatalyst ILS had been investigated for the Knoevenagel condensation reaction of different aromatic and heteroaromatic aldehyde with ethyl cyanoacetate in solvent free conditions. The catalyst ILS was found to be efficient to catalyze the condensation effectively leading the completion of the reaction within 6 min using single mode microwave irradiation.

Graphical abstract.Figure optionsDownload full-size imageDownload high-quality image (115 K)Download as PowerPoint slideHighlights► Microwave mediated morphosynthesis of ILS SBA-15. ► The ILS SBA-15 short channel, platelet morphology and high pore size distribution. ► Microwave mediated Knoevenagel condensation reaction was carried within 6 min. ► The reaction proceeded under solvent free conditions.