Supported Ionic Liquid on Silica Gel: A Novel Heterogeneous Catalyst for the Synthesis of α,β-Unsaturated Compounds

In this study, supported tris(hydroxymethyl)methane ammonium acetate ionic liquid on silica gel (SiO2-THMAA) was synthesized for the first time. SiO2-THMAA was prepared by the reaction of 3-chloropropylsilica with  tris(hydroxymethyl) aminomethane followed by ion exchange with acetate. SiO2-THMAA was characterized by FT-IR, BET, and elemental analysis. Also, to explore the catalytic activity of SiO2-THMAA in organic reactions, the synthesis of α,β-unsaturated compounds was investigated in the presence of SiO2-THMAA as a heterogeneous catalyst at room temperature. The desired products were produced in high yields and short times in mild reaction conditions. SiO2-THMAA was also recovered and reused after the three reaction cycle without a significant decrease in catalytic activity.