Materials Today Communications
γ-Fe2O3@SiO2(CH2)3-HPBM-Pd as a versatile boosted nanocatalyst for carboncarbon bond formation
Introduction
Carbon-carbon bond formations are of the most significant reactions in organic chemistry. [[1], [2], [3]] Among several methods and catalysts, which are introduced for these reactions, Pd-catalyzed reactions are of high interest due to their unique properties [[4], [5], [6], [7]]. Palladium is a transition metal and is widely used in several organic transformations, including hydrogenation [8], CO oxidation [9], acetylation of allylic C–H bond [10], oxygen reduction [11], nitrophenol reduction [12], and etc. Mizoroki-Heck and Suzuki-Miyaura cross-coupling are two classes of palladium-catalyzed carbon-carbon bond formation reactions in organic synthesis [[13], [14], [15], [16], [17]]. The advantage of palladium nanoparticle catalysts is their high efficiency for performing the mentioned reactions in water. In addition, the catalyst is highly active with high TON. The reusability evaluation of the catalyst showed that the catalyst is recyclable and the activity of the catalyst has not lost in 10 sequential runs [18,19].
A challenging issue in the field of the expensive catalysts is their recovery after the reaction completion. An efficient approach for overcoming this issue is to immobilize the catalysts on solid supports. Using nanoparticles as supports is an advantageous approach, while provides the benefits of both homogeneous and heterogeneous catalysis. By applying NPs as support, the high activity of the catalyst could be obtained with the possibility of the simple recovery of the catalysts [[20], [21], [22], [23], [24], [25]]. Superparamagnetic iron oxide NPs (SPIONs) are an interesting class of NPs with magnetic properties, which are widely used in several applications, including drug delivery [26,27], MRI contrast agent [28,29], adsorption [30], and catalyst supports [31,32]. Silica coated SPIONs have active hydroxyl groups and therefore could be functionalized by various functionalized groups. By this method, SPIONs could be modified by suitable functional groups, which could role as a ligand for transition metal catalysts [[33], [34], [35]]. It should be noted that two kinds of SPIONs are the most common nanoparticles, which are used as support for catalysts: magnetite (Fe3O4) [36] and maghemite (γ-Fe2O3) [37]. In addition, only a limited variety of ligands with one, two, or more donating isolated fragments, has been used for the synthesis of these types of catalysts [[38], [39], [40], [41]]. On the other hand, benzimidazole and its derivatives are efficient and unique ligands for several transition metals for applications in a wide variety of applications, especially in catalysis [[42], [43], [44], [45]]. In this regard, developing novel ligands for functionalization of NPs with the applicability of coordination to Pd catalytic center is yet a challenging issue.
Due to the significance of the design and synthesis of novel ligands for palladium on one hand, and the applicability of SPIONs as support nanomaterial on the other hand, herein, we report a nanocatalyst based on SPIONs functionalized by 2-(2′-hydroxyphenyl)-benzothiazole (HPBM) moieties as a novel supporting base for palladium. This nanocatalyst (denoted γ-Fe2O3@SiO2(CH2)3-HPBM-Pd NPs) is evaluated for Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions.
Section snippets
Results and discussion
In this paper, 2-(2′-hydroxyphenyl)-benzothiazole (HPBM) functionalized SPIONs were synthesized and used as support for palladium catalyst. To do this, SPIONs fabricated by the reaction of Fe2+ and Fe3+ in basic media, was encapsulated by SiO2 via the reaction with tetraethyl orthosilicate (TEOS) to form γ-Fe2O3@SiO2. 3,4-Diaminobenzoic acid was separately reacted with 2-hydroxybenzaldehyde and formed 2-(2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylic acid (3). The synthesized
General remarks
All the chemicals and solvents were purchased from Merck, Sigma, and Acros chemicals and were used in the reactions without any purifications. TEM of the samples were recorded on a CM 10 Philips instrument. 1H (500 MHz) spectra were recorded on a Bruker Avance spectrometer in DMSO, d6 solution with tetramethylsilane (TMS) as an internal standard. SEM images were recorded on a TESCAN T3000 instrument. OPTIMA7300DV ICP analyzer was applied for analyzing the palladium content of the catalyst. The
Conclusion
In conclusion, the designed and synthesized of a novel catalyst is reported based on the immobilization of palladium onto modified magnetic iron oxide nanoparticles. For the synthesis of the catalyst, silica capsulated SPIONs were synthesized and functionalized by HPBM as a ligand for catalyst. 2-(2-Hydroxyphenyl)-N-(3-(triethoxysilyl)propyl)-1H-benzo[d]imidazole-5-carboxamide was used as modification, which was synthesized from the reaction of 3,4-diaminobenzoic acid and 2-hydroxybenzaldehyde,
Declaration of Competing Interest
The authors declare that they have no known competing for financial interests or personal relationships that could have appeared to influence the work reported in this paper.
References (54)
- et al.
Appl. Catal. B
(2012) - et al.
Electrochim. Acta
(2012) - et al.
J. Organomet. Chem.
(2019) - et al.
Coord. Chem. Rev.
(2019) - et al.
Appl. Catal. A Gen.
(2013) - et al.
Coord. Chem. Rev.
(2016) - et al.
Microporous Mesoporous Mater.
(2018) - et al.
J. Magn. Magn. Mater.
(2016) - et al.
J. Ind. Eng. Chem.
(2018) - et al.
Int. J. Biol. Macromol.
(2019)
J. Mol. Catal. A Chem.
J. Mol. Catal. A Chem.
Catal. Commun.
J. Am. Chem. Soc.
Science
Chem. Lett.
Chem. Eur. J.
J. Am. Chem. Soc.
RSC Adv.
Polym. Adv. Technol.
Angew. Chemie Int. Ed.
J. Am. Chem. Soc.
J. Mater. Chem. A
Catal. Letters
Chem. Soc. Rev.
Molecules
ACS Sustain. Chem. Eng.
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2022, TetrahedronCitation Excerpt :The chemical modification of γ-Fe2O3@SiO2 nanoparticles by 2-(2′-hydroxyphenyl)-benzothiazole (HPBM) functionality is often used as an effective ligand for palladium ions, results in γ-Fe2O3@SiO2(CH2)3-HPBM-Pd (VII) nanocatalyst (Fig. 9). The (VII) nanoparticles showed great catalytic activity for the Mizoroki-Heck and Suzuki-Miyaura [120] cross-coupling reactions (Scheme 7). M. Bharamanagowda and Panchangam (2020) reported palladium nanoparticles (PdNPs) in water under eco-friendly conditions by reducing PdCl2 with NaOH and supporting them with Fe3O4-Lignin.
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