One-Pot Synthesis of Deep Eutectic Solvents Containing Three-Dimensional Polymeric Materials with Excellent Catalytic Activity in the Knoevenagel Condensation Reaction

Abstract

Deep eutectic solvents (DESs)-containing three-dimensional (3D) porous organic polymers (termed TAM-BPA-ChCl/Ur, TAM-BPA-ChCl/Gly, and TAM-BPA-Bu 4 NBr/Im) were obtained via one-pot synthesis by using DESs as green reaction solvents for the first time. The DESs were confined into 3D extended structures during the synthetic process, as revealed by a series of techniques. The DESs-loaded polymeric materials were used to catalyze the Knoevenagel condensation of aldehydes and malononitrile and produced excellent yields at room temperature. As a typical example, the TAM-BPA-ChCl/Ur sample as a heterogeneous catalyst can be recovered easily and shows stable catalytic activity. This research presents a feasible method to prepare functional complex materials involving DESs and porous polymers.

Urea-rich porous organic polymer as a hydrogen bond catalyst for Knoevenagel condensation reaction and synthesis of 2,3-dihydroquinazolin-4(1H)-ones

“…Urealinked POPs can enhance the synergistic reaction strategy with the incorporation of two or more active sites in close proximity to activate the reactants which leads to a decrease in the activation energy barrier. 34 Considering the above, POPs, especially urealinked POPs, are benecial precursors for many catalytic transformations such as Knoevenagel condensation, 38 cross coupling reactions, 39 oxidation and reduction reactions, 39 asymmetric catalysis, 40 arylation reactions 27 CO 2 xation, 41 photocatalytic reactions 42 and multi-component reactions. 43 Knoevenagel condensation, as a forefront and fundamental reaction for C]C bond formation, is an important reaction to achieving carbohydrates, fragrances, herbicides and dyes.…”