Assembly immobilized palladium(0) on carboxymethylcellulose/Fe₃O₄ hybrid: An efficient tailor‐made magnetically catalyst for the Suzuki–Miyaura couplings

Abstract

The Pd nanoparticles (Pd NPs) embedded on magnetically retrievable carboxymethylcellulose/Fe 3 O 4 (Pd 0 @CMC/Fe 3 O 4 ) organic/inorganic hybrid were prepared via the conventional simple process. The presence of the hydroxyl and carboxyl groups within the framework of the magnetic hybrid enables the facile preparation and stabilization of Pd NPs in this organic/inorganic hybrid. This hybrid catalyst was very effective in the Suzuki-Miyaura reaction of a variety of aryl halides with arylboronic acid to afford excellent product yields. The catalyst showed good stability and could be easily recovered with an external magnetic field and reused for several times without a significant loss in its catalytic activity. Furthermore, the Pd 0 @CMC/ Fe 3 O 4 hybrid catalyst was fully characterized by UV-Vis, FT-IR, XRD, SEM, EDX, TEM, XPS and TGA techniques. The hot filtration test suggests that a homogeneous mechanism is operative in Suzuki-Miyaura reaction.

Nanopalladium on Magnetic Ionic Nanoparticle Network (MINN) as an Efficient and Recyclable Catalyst with High Ionic Density and Dispersibility

“…The Suzuki–Miyaura reaction is one of the most important C–C coupling reactions which lead to the synthesis of biaryl derivatives as key compounds in the production of fine chemicals, conducting polymers, herbicides, natural products, and pharmaceuticals. − This reaction has been traditionally accomplished in the presence of homogeneous palladium catalysts employing phosphine ligands − and N -heterocyclic carbenes − or palladacycle complexes. , However, most of these homogeneous systems suffer from several limitations such as difficulty in catalyst separation and recovery, requiring high catalyst loading, poisoning or deactivation of catalyst, and product contamination. To overcome these drawbacks, the immobilized catalysts have attracted particular attention, and various solid supports such as mesoporous and amorphous silica, − polymers, − zeolites, metal oxides, carbon material, − and magnetic nanoparticles or nanocomposites − have been applied for Pd-catalyzed Suzuki reaction. As mentioned earlier, the great challenge in the case of these systems is the capability of support to stabilize or recapture highly active and small Pd species during the course of reaction.…”

Encapsulation of palladium chloride using 2‐formylbenzoic acid supported by Fe3O4 nanoparticles modified with SiO2 and propylamine, its characterization and its application for Suzuki coupling reaction

“…The catalyst was removed from the reaction mixture using an external magnet, and was used several times without significant loss of its catalytic activity. Pd-NPs@S. lavandulifolia Iodobenzene 98 60 60 [50] Pd/C-C catalyst Iodobenzene 90 60 60 [26] Pd NPs@Hibiscus sabadariffa L. Iodobenzene 95 120 80°C [51] Palladacycle complex Iodobenzene 91 90 120 [52] Pd0@CMC/Fe 3 O 4 Iodobenzene 80 30 78 [49] Pd-SBTU@Fe 3 O 4 Iodobenzene 92 420 80 [53] Fe 3 O 4 @SiO 2 (CH 2 ) 3 N-CH-Ar@Pd(0) Iodobenzene 98 20 75 Present work…”

“…In the final step, reductive elimination occurs and biaryl is formed (Scheme 2). [49,50] Table 3 presents a comparison of the activity of the synthesized nanocatalyst with those of other palladium catalysts reported in the literature. The advantage of the present protocol is that the Suzuki reaction is carried out in less time and the reaction efficiency is higher, so it is superior to other reported methods.…”

CuSO4 nanoparticles loaded on carboxymethylcellulose/polyaniline composites: A highly efficient catalyst with enhanced catalytic activity in the synthesis of propargylamines, benzofurans, and 1,2,3‐triazoles

“…According to the spectrum of CMC─Na (curve a), the characteristic absorption peaks at 1,607 and 1,424 cm À1 are, respectively, assigned to the asymmetric and symmetric stretching vibration of carboxylate (─COO À ) groups. [17][18][19][20] In the spectrum of PANI (curve b), the peaks at 1,558 and 1,126 cm À1 are attributed to the moiety of N═Q═N (where Q represents a quinoid ring), while the peak at 1,482 and 802 cm À1 are correlated to the structure of N─B─N (where B represents a benzenoid ring). [31] From the spectrum of CuSO4NPs@CMC/PANI composites (curve c), a new absorption band at around 1,159 cm À1 is indicative for the SO 4 2À presence, [35] which may be due to the presence The X-ray diffraction (XRD) patterns of the CMC─Na (curve a), PANI (curve b), and CuSO 4 NPs@CMC/PANI composites (curve c) were shown in Figure 6.…”

“…[15] Polyaniline (PANI), composed of benzoid and quinoid moieties, is a useful supportive material due to the unique coordination with metal ions via lone-pair electrons present in the nitrogen atoms and delocalized π-π conjugate system of PANI. [16] Based on these unique properties, a number of CMC-based [17][18][19][20] and PANIbased [16,21,22] composite catalysts recently have been reported. Although these reported catalysts have excellent catalytic activity, the shortcomings such as poor mechanical strength, multistep synthetic approaches, and tedious operation in some cases are the main disadvantage that needs to be optimized.…”