Sodium Carboxymethylcellulose: A Low‐Cost and Renewable Catalyst for Solvent‐Free Knoevenagel Condensation Reaction at Room Temperature

Abstract

The commercially available sodium carboxymethylcellulose (CMC−Na) has been used as a low‐cost catalyst for Knoevenagel condensation reaction under solvent‐free condition at room temperature. The results show that CMC−Na is robust enough to catalyze Knoevenagel condensation reactions of a series of aldehydes containing electron‐donating and electron‐withdrawing groups with malononitrile to produce the corresponding products with good to excellent yields. This excellent catalytic efficiency can be attributed to the peculiar catalytic capacity of carboxylate groups (−COO−) with the assistance of the hydroxyl groups (‐OH). In addition, the CMC−Na was very stable and could be recycled for at least 8 consecutive runs without significant loss of its catalytic performance.

A post-sulfonated one-pot synthesized magnetic cellulose nanocomposite for Knoevenagel and Thorpe–Ziegler reactions

“… 39 Sodium carboxymethylcellulose has also been reported as a catalyst for Knoevenagel condensation in 98% yield under solvent-free conditions and at room temperature. 40 Herein, magnetic cellulose nanocrystals, MCNCs, were hydrothermally synthesized in a one-pot reaction and then post-sulfonated using chlorosulfonic acid (CSA), producing sulfonated MCNCs (SMCNCs), as illustrated in Fig. 1 .…”

Ultrasonication‐assisted Synthesis of α, β‐Unsaturated Compounds Catalyzed by Amino‐functionalized FDU‐12 Catalyst

“…Knoevenagel condensation reaction is one of the most important carbon–carbon bond formation reactions, which is widely used to manufacture α , β ‐unsaturated compounds . This reaction can be accomplished by treating a aldehyde with an active methylene compound in the presence of various homogeneous or heterogeneous basic catalysts, such as sodium carboxymethylcellulose, metal co‐ordinated organic xerogel, ionic liquids, nitrogen doped CN x , Pd/AlO(OH), et al.. However, there are some shortcomings for these reported catalysts, such as low activity, non‐environmentally friendly solvents requirement and unrecyclable .…”