Proline-Cu Complex Based 1,3,5-Triazine Coated on Fe₃O₄ Magnetic Nanoparticles: A Nanocatalyst for the Knoevenagel Condensation of Aldehyde with Malononitrile

Abstract

In the present work, based on a convergent protocol, we synthesized proline-Cu complex based 1,3,5-triazine coated on Fe3O4 magnetic nanoparticles as a green and recyclable nanocatalyst by an inexpensive and simple procedure. Then, fully specified by Fourier transform infrared spectroscopy (FT-IR), we pursued field emission scanning electron microscopy (FESEM), vibrating sample magnetometry (VSM), powder X-ray diffraction (PXRD), energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), and Brunauer–Emmet–Teller (BET) and inductively coupled plasma (ICP) analysis. The catalytic movement of the synthesized nanocatalyst underwent successful investigation in the Knoevenagel condensation through malononitrile as well as various aldehydes in H2O as a green solvent at room temperature. The high efficiency, short reaction time, ecofriendly properties, and easy workup can be considered the major benefits of the current method. Also, the separation of the nanocatalyst was easily performed by an external magnet and applied again for eight fresh runs with no considerable loss of catalytic activity.

Is a Catalyst Always Needed? The Case of the Knoevenagel Reaction with Malononitrile

“…[47] Proline-Cu complex based 1,3,5triazine coated on Fe 3 O 4 magnetic nanoparticles (L-proline-Cu/ TCT@NH 2 @Fe 3 O 4 ) was used in water at rt (entries 12-13). [48] 1-Butyl-3-vinylimidazolium chloride was polymerized with acrylamide to furnish an ionic liquid-containing polymer, which was then used for the formation of a composite with iron-based metal-organic framework. This material was used in water under reflux (entries 14-15).…”

“…A blank test was performed only in THF, then, the role of the catalyst in some of the reported reactions could be negligible (entries 10–11) [47] . Proline‐Cu complex based 1,3,5‐triazine coated on Fe 3 O 4 magnetic nanoparticles (L‐proline‐Cu/TCT@NH 2 @Fe 3 O 4 ) was used in water at rt (entries 12–13) [48] . 1‐Butyl‐3‐vinylimidazolium chloride was polymerized with acrylamide to furnish an ionic liquid‐containing polymer, which was then used for the formation of a composite with iron‐based metal‐organic framework.…”

Silica supported spinel structured cobalt ferrite multifunctional nanocatalyst for hydration of nitriles and oxidative decarboxylation of phenylacetic acids

“…We thought that SiO 2 may modify the surface of CoFe 2 O 4 to enhance its physical and chemical stability since support plays a major role for accomplishing sufficient reactivity as well as non-leaching of metal species. [16,17] Several methods have already been reported for the synthesis of spinel structured cobalt ferrite nanoparticles. However, many of these methods used toxic organic reagents such as ethylene glycol, [18] polyethylene glycol, [19] and so forth, organic acids as capping agent (citric acid, [20] sulfonic acid, [21] nicotinic acid, [22] lauric acid, [23] etc.…”

Highly Active Cyclic Zinc(II) Thione Catalyst for C−C and C−N Bond Formation Reactions

“…The classic C−C double bond‐forming reaction such as the Knoevenagel condensation reaction has been extensively employed for the synthesis of fine chemicals for materials and medicinal applications [1–4] . Many synthetic methodologies have been developed using a variety of catalysts, including ionic liquids, [5] organocatalysts, [6] metal‐based catalysts such as Lewis acids, Lewis acid‐base pairs, [7a,b] MOFs, [8] and various nanocatalysts [9] . However, metal‐based catalysts have several limitations due to environmental toxicity, selectivity, sustainability, elevated temperature, longer reaction time, limited substrate scope, and uses of additives.…”

“…[1][2][3][4] Many synthetic methodologies have been developed using a variety of catalysts, including ionic liquids, [5] organocatalysts, [6] metal-based catalysts such as Lewis acids, Lewis acid-base pairs, [7a,b] MOFs, [8] and various nanocatalysts. [9] However, metal-based catalysts have several limitations due to environmental toxicity, selectivity, sustainability, elevated temperature, longer reaction time, limited substrate scope, and uses of additives. As a consequence, a new catalytic approach that is free of such problems is highly anticipated.…”