Articles de revues : « Heterogeneous Catalysis - Organic Chemistry »

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Motokura, Ken, et Kyogo Maeda. « Recent Advances in Heterogeneous Ir Complex Catalysts for Aromatic C–H Borylation ». Synthesis 53, n^o 18 (9 avril 2021) : 3227–34. http://dx.doi.org/10.1055/a-1478-6118.

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AbstractAromatic C–H borylation catalyzed by an Ir complex is among the most powerful methods for activating inert bonds. The products, i.e., arylboronic acids and their esters, are usable chemicals for the Suzuki–Miyaura cross-coupling reaction, and significant effort has been directed toward the development of homogeneous catalysis chemistry. In this short review, we present a recent overview of current heterogeneous Ir-complex catalyst developments for aromatic C–H borylation. Not only have Ir complexes been immobilized on support surfaces with phosphine and bipyridine ligands, but Ir complexes incorporated within solid materials have also been developed as highly active and reusable heterogeneous Ir catalysts. Their catalytic activities and stabilities strongly depend on their surface structures, including linker length and ligand structure.1 Introduction and Homogeneous Ir Catalysis2 Heterogeneous Ir Complex Catalysts for C–H Borylation Reactions3 Other Heterogeneous Metal Complex Catalysts for C–H Borylation Reactions4 Summary and Outlook

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Leino, Reko, Dmitry Yu Murzin et Tiina Saloranta. « Bridging Organic Chemistry and Heterogeneous Catalysis ». Topics in Catalysis 59, n^o 13-14 (1 juin 2016) : 1095–96. http://dx.doi.org/10.1007/s11244-016-0634-7.

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Kokel, Anne, Christian Schäfer et Béla Török. « Organic Synthesis Using Environmentally Benign Acid Catalysis ». Current Organic Synthesis 16, n^o 4 (4 juillet 2019) : 615–49. http://dx.doi.org/10.2174/1570179416666190206141028.

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Recent advances in the application of environmentally benign acid catalysts in organic synthesis are reviewed. The work includes three main parts; (i) description of environmentally benign acid catalysts, (ii) synthesis with heterogeneous and (iii) homogeneous catalysts. The first part provides a brief overview of acid catalysts, both solid acids (metal oxides, zeolites, clays, ion-exchange resins, metal-organic framework based catalysts) and those that are soluble in green solvents (water, alcohols) and at the same time could be regenerated after reactions (metal triflates, heteropoly acids, acidic organocatalysts etc.). The synthesis sections review a broad array of the most common and practical reactions such as Friedel-Crafts and related reactions (acylation, alkylations, hydroxyalkylations, halogenations, nitrations etc.), multicomponent reactions, rearrangements and ring transformations (cyclizations, ring opening). Both the heterogeneous and homogeneous catalytic synthesis parts include an overview of asymmetric acid catalysis with chiral Lewis and Brønsted acids. Although a broad array of catalytic processes are discussed, emphasis is placed on applications with commercially available catalysts as well as those of sustainable nature; thus individual examples are critically reviewed regarding their contribution to sustainable synthesis.

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Baráth, Eszter. « Selective Reduction of Carbonyl Compounds via (Asymmetric) Transfer Hydrogenation on Heterogeneous Catalysts ». Synthesis 52, n^o 04 (2 janvier 2020) : 504–20. http://dx.doi.org/10.1055/s-0039-1691542.

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Based on the ever-increasing demand for optically pure compounds, the development of efficient methods to produce such products is very important. Homogeneous asymmetric catalysis occupies a prominent position in the ranking of chemical transformations, with transition metals coordinated to chiral ligands being applied extensively for this purpose. However, heterogeneous catalysts have the ability to further extend the field of asymmetric transformations, because of their beneficial properties such as high stability, ease of separation and regeneration, and the possibility to apply them in continuous processes. The main challenge is to find potential synthetic routes that can provide a chemically and thermally stable heterogeneous catalyst having the necessary chiral information, whilst keeping the catalytic activity and enantioselectivity equally high (or even higher) than the corresponding homogeneous counterpart. Within this short review, the most relevant immobilization modes and preparative strategies depending on the support material used are summarized. From the reaction scope viewpoint, metal catalysts supported on the various solid materials studied in (asymmetric) transfer hydrogenation of carbonyl compounds are selected and represent the main focus of the second part of this overview.1 Introduction2 Synthesis of Chiral Heterogeneous Catalysts2.1 Immobilization of Homogeneous Asymmetric Catalysts2.1.1 Immobilization on Inorganic Supports2.1.2 Immobilization on Organic Polymers as Supports2.1.3 Immobilization on Dendrimer-Type Materials as Supports2.1.4 Self-Supported Chiral Catalysts: Coordination Polymers2.1.5 Immobilization Using Non-Conventional Media2.2 Chirally Modified Metal Surfaces for Heterogeneous Asymmetric Catalysis3 Examples of Transfer Hydrogenation on Heterogeneous Catalysts3.1 Silicon-Immobilized Catalysts3.2 Carbon-Material-Immobilized Catalysts3.3 Polymer-Immobilized Catalysts3.4 Magnetic-Nanoparticle-Immobilized Catalysts4 Conclusions

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Rubab, Laila, Ayesha Anum, Sami A. Al-Hussain, Ali Irfan, Sajjad Ahmad, Sami Ullah, Aamal A. Al-Mutairi et Magdi E. A. Zaki. « Green Chemistry in Organic Synthesis : Recent Update on Green Catalytic Approaches in Synthesis of 1,2,4-Thiadiazoles ». Catalysts 12, n^o 11 (29 octobre 2022) : 1329. http://dx.doi.org/10.3390/catal12111329.

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Green (sustainable) chemistry provides a framework for chemists, pharmacists, medicinal chemists and chemical engineers to design processes, protocols and synthetic methodologies to make their contribution to the broad spectrum of global sustainability. Green synthetic conditions, especially catalysis, are the pillar of green chemistry. Green chemistry principles help synthetic chemists overcome the problems of conventional synthesis, such as slow reaction rates, unhealthy solvents and catalysts and the long duration of reaction completion time, and envision solutions by developing environmentally benign catalysts, green solvents, use of microwave and ultrasonic radiations, solvent-free, grinding and chemo-mechanical approaches. 1,2,4-thiadiazole is a privileged structural motif that belongs to the class of nitrogen–sulfur-containing heterocycles with diverse medicinal and pharmaceutical applications. This comprehensive review systemizes types of green solvents, green catalysts, ideal green organic synthesis characteristics and the green synthetic approaches, such as microwave irradiation, ultrasound, ionic liquids, solvent-free, metal-free conditions, green solvents and heterogeneous catalysis to construct different 1,2,4-thiadiazoles scaffolds.

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Pagliaro, Mario, Cristina Della Pina, Francesco Mauriello et Rosaria Ciriminna. « Catalysis with Silver : From Complexes and Nanoparticles to MORALs and Single-Atom Catalysts ». Catalysts 10, n^o 11 (19 novembre 2020) : 1343. http://dx.doi.org/10.3390/catal10111343.

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Silver catalysis has a rich and versatile chemistry now expanding from processes mediated by silver complexes and silver nanoparticles to transformations catalyzed by silver metal organic alloys and single-atom catalysts. Focusing on selected recent advances, we identify the key advantages offered by these highly selective heterogeneous catalysts. We conclude by offering seven research and educational guidelines aimed at further progressing the field of new generation silver-based catalytic materials.

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Augustine, Robert L., et Shaun T. O'Leary. « Heterogeneous catalysis in organic chemistry Part 8. » Journal of Molecular Catalysis 72, n^o 2 (mars 1992) : 229–42. http://dx.doi.org/10.1016/0304-5102(92)80048-l.

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Shetty, Apoorva, Vandana Molahalli, Aman Sharma et Gurumurthy Hegde. « Biomass-Derived Carbon Materials in Heterogeneous Catalysis : A Step towards Sustainable Future ». Catalysts 13, n^o 1 (23 décembre 2022) : 20. http://dx.doi.org/10.3390/catal13010020.

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Biomass-derived carbons are emerging materials with a wide range of catalytic properties, such as large surface area and porosity, which make them ideal candidates to be used as heterogeneous catalysts and catalytic supports. Their unique physical and chemical properties, such as their tunable surface, chemical inertness, and hydrophobicity, along with being environmentally friendly and cost effective, give them an edge over other catalysts. The biomass-derived carbon materials are compatible with a wide range of reactions including organic transformations, electrocatalytic reactions, and photocatalytic reactions. This review discusses the uses of materials produced from biomass in the realm of heterogeneous catalysis, highlighting the different types of carbon materials derived from biomass that are potential catalysts, and the importance and unique properties of heterogeneous catalysts with different preparation methods are summarized. Furthermore, this review article presents the relevant work carried out in recent years where unique biomass-derived materials are used as heterogeneous catalysts and their contribution to the field of catalysis. The challenges and potential prospects of heterogeneous catalysis are also discussed.

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Wan, Qiang, Sen Lin et Hua Guo. « Frustrated Lewis Pairs in Heterogeneous Catalysis : Theoretical Insights ». Molecules 27, n^o 12 (10 juin 2022) : 3734. http://dx.doi.org/10.3390/molecules27123734.

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Frustrated Lewis pair (FLP) catalysts have attracted much recent interest because of their exceptional ability to activate small molecules in homogeneous catalysis. In the past ten years, this unique catalysis concept has been extended to heterogeneous catalysis, with much success. Herein, we review the recent theoretical advances in understanding FLP-based heterogeneous catalysis in several applications, including metal oxides, functionalized surfaces, and two-dimensional materials. A better understanding of the details of the catalytic mechanism can help in the experimental design of novel heterogeneous FLP catalysts.

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Lévay, Krisztina, et László Hegedűs. « Recent Achievements in the Hydrogenation of Nitriles Catalyzed by Transitional Metals ». Current Organic Chemistry 23, n^o 18 (26 novembre 2019) : 1881–900. http://dx.doi.org/10.2174/1385272823666191007160341.

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Amines are important and valuable intermediates in the pharmaceutical, plastic and agrochemical industry. Hence, there is an increasing interest in developing improved process for the synthesis of amines. The heterogeneous catalytic hydrogenation of nitriles is one of the most frequently applied methods for the synthesis of diverse amines, but the homogeneous catalysis has also received a growing attention from the catalysis community. This mini-review provides an overview of the recent achievements in the selective reduction of nitriles using both homogeneous and heterogeneous transition metal catalysts.

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Al-Omari, Abdulhadi, Zain Yamani et Ha Nguyen. « Electrocatalytic CO2 Reduction : From Homogeneous Catalysts to Heterogeneous-Based Reticular Chemistry ». Molecules 23, n^o 11 (1 novembre 2018) : 2835. http://dx.doi.org/10.3390/molecules23112835.

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CO2, emitted mainly from fossil fuel combustion, is one of the major greenhouse gases. CO2 could be converted into more valuable chemical feedstocks including CO, HCOOH, HCHO, CH3OH, or CH4. To reduce CO2, catalysts were designed and their unique characteristics were utilized based on types of reaction processes, including catalytic hydrogenation, complex metal hydrides, photocatalysis, biological reduction, and electrochemical reduction. Indeed, the electroreduction method has received much consideration lately due to the simple operation, as well as environmentally friendly procedures that need to be optimized by both of the catalysts and the electrochemical process. In the past few decades, we have witnessed an explosion in development in materials science—especially in regards to the porous crystalline materials based on the strong covalent bond of the organic linkers containing light elements (Covalent organic frameworks, COFs), as well as the hybrid materials that possess organic backbones and inorganic metal-oxo clusters (Metal-organic frameworks, MOFs). Owing to the large surface area and high active site density that belong to these tailorable structures, MOFs and COFs can be applied to many practical applications, such as gas storage and separation, drug release, sensing, and catalysis. Beyond those applications, which have been abundantly studied since the 1990s, CO2 reduction catalyzed by reticular and extended structures of MOFs or COFs has been more recently turned to the next step of state-of-the-art application. In this perspective, we highlight the achievement of homogeneous catalysts used for CO2 electrochemical conversion and contrast it with the advances in new porous catalyst-based reticular chemistry. We then discuss the role of new catalytic systems designed in light of reticular chemistry in the heterogeneous-catalyzed reduction of CO2.

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Damera, Thirupathi, Ramakanth Pagadala, Surjyakanta Rana et Sreekantha Babu Jonnalagadda. « A Concise Review of Multicomponent Reactions Using Novel Heterogeneous Catalysts under Microwave Irradiation ». Catalysts 13, n^o 7 (24 juin 2023) : 1034. http://dx.doi.org/10.3390/catal13071034.

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Multi-component reactions for the construction of heterocycles have been fascinated by microwave energy as an alternative technique of heating, owing to the advantages over traditional reflux methods. The heterogeneous catalysts contribute significantly towards recycling, harmless, easy filtration, catalyst preparation, more life span, abundance, and product yields. With novel and creative uses in organic and peptide synthesis, polymer chemistry, material sciences, nanotechnology, and biological processes, the usage of microwave energy has rapidly increased during the past 20 years. This article covers multicomponent reactions involving construction of chromenes, pyridines, pyrroles, triazoles, pyrazoles, tetrazoles, trans and cis julolidines using heterogeneous catalysts under microwave. It provides an overview of contemporary microwave-assisted heterogeneous catalytic reactions. Microwave chemistry is now an established technology with several advantages regarding reaction rate and production yield, improving energy savings as confirmed by many applications. Due to the widespread curiosity in medicinal chemistry, the heterogeneously catalysed construction of heterocycles under microwave irradiation is explored to reduce time and energy. By considering various aspects of economy, eco-friendly, and user-friendly factors, this review focuses on recent advances in the multi-component construction of heterocycles using heterogeneous catalysts under microwave irradiation. This review also discusses the benefits and limitations of reaction conditions and yields from the literature reports for the past five years.

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Laszlo, Pierre. « Heterogeneous catalysis of organic reactions ». Journal of Physical Organic Chemistry 11, n^o 5 (mai 1998) : 356–61. http://dx.doi.org/10.1002/(sici)1099-1395(199805)11:5<356 ::aid-poc33>3.0.co;2-h.

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Cirujano, Francisco G., Rafael Luque et Amarajothi Dhakshinamoorthy. « Metal-Organic Frameworks as Versatile Heterogeneous Solid Catalysts for Henry Reactions ». Molecules 26, n^o 5 (7 mars 2021) : 1445. http://dx.doi.org/10.3390/molecules26051445.

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Metal–organic frameworks (MOFs) have become one of the versatile solid materials used for a wide range of applications, such as gas storage, gas separation, proton conductivity, sensors and catalysis. Among these fields, one of the more well-studied areas is the use of MOFs as heterogeneous catalysts for a broad range of organic reactions. In the present review, the employment of MOFs as solid catalysts for the Henry reaction is discussed, and the available literature data from the last decade are grouped. The review is organized with a brief introduction of the importance of Henry reactions and structural properties of MOFs that are suitable for catalysis. The second part of the review discusses the use of MOFs as solid catalysts for the Henry reaction involving metal nodes as active sites, while the third section provides data utilizing basic sites (primary amine, secondary amine, amides and urea-donating sites). While commenting on the catalytic results in these two sections, the advantage of MOFs over other solid catalysts is compared in terms of activity by providing turnover number (TON) values and the structural stability of MOFs during the course of the reaction. The final section provides our views on further directions in this field.

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Yang, Qiming, Hu Wang, Xiang Wang et Yizhu Lei. « Recent Developments in Direct C–H Functionalization of Quinoxalin-2(1H)-Ones via Heterogeneous Catalysis Reactions ». Molecules 28, n^o 13 (27 juin 2023) : 5030. http://dx.doi.org/10.3390/molecules28135030.

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In recent years, Web of Science has published nearly one hundred reports per year on quinoxalin-2(1H)-ones, which have attracted great interest due to their wide applications in pharmaceutical and materials fields, especially in recyclable heterogeneous catalytic reactions for direct C–H functionalisation. This review summarises for the first time the methods and reaction mechanisms of heterogeneous catalytic reactions of quinoxalin-2(1H)-ones, including six major types of heterogeneous catalysts involved. The heterogeneous reactions of quinoxalin-2(1H)-ones are summarised by classifying different types of catalytic materials (graphitic phase carbon nitride, MOF, COF, ion exchange resin, piezoelectric materials, and microsphere catalysis). In addition, this review discusses the future development of heterogeneous catalytic reactions of quinoxalin-2(1H)-ones, including the construction of C-B/Si/P/RF/X/Se bonds by heterogeneous catalytic reactions, the enrichment of heterogeneous catalysts such as metal oxides, graphene-based composites, doped metal nanoparticles, and molecular sieve-based porous materials, asymmetric synthesis, and other areas. The aim of this review is to contribute to the development of green and sustainable heterogeneous reaction methods for quinoxalin-2(1H)-ones with applications in materials chemistry and pharmacology.

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Zhang, Leilei, Yujing Ren, Wengang Liu, Aiqin Wang et Tao Zhang. « Single-atom catalyst : a rising star for green synthesis of fine chemicals ». National Science Review 5, n^o 5 (2 août 2018) : 653–72. http://dx.doi.org/10.1093/nsr/nwy077.

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Abstract The green synthesis of fine chemicals calls for a new generation of efficient and robust catalysts. Single-atom catalysts (SACs), in which all metal species are atomically dispersed on a solid support, and which often consist of well-defined mononuclear active sites, are expected to bridge homogeneous and heterogeneous catalysts for liquid-phase organic transformations. This review summarizes major advances in the SAC-catalysed green synthesis of fine chemicals in the past several years, with a focus on the catalytic activity, selectivity and reusability of SACs in various organic reactions. The relationship between catalytic performance and the active site structure is discussed in terms of the valence state, coordination environment and anchoring chemistry of single atoms to the support, in an effort to guide the rational design of SACs in this special area, which has traditionally been dominated by homogeneous catalysis. Finally, the challenges remaining in this research area are discussed and possible future research directions are proposed.

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De Coster, Valentijn, Hilde Poelman, Jolien Dendooven, Christophe Detavernier et Vladimir V. Galvita. « Designing Nanoparticles and Nanoalloys for Gas-Phase Catalysis with Controlled Surface Reactivity Using Colloidal Synthesis and Atomic Layer Deposition ». Molecules 25, n^o 16 (15 août 2020) : 3735. http://dx.doi.org/10.3390/molecules25163735.

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Supported nanoparticles are commonly applied in heterogeneous catalysis. The catalytic performance of these solid catalysts is, for a given support, dependent on the nanoparticle size, shape, and composition, thus necessitating synthesis techniques that allow for preparing these materials with fine control over those properties. Such control can be exploited to deconvolute their effects on the catalyst’s performance, which is the basis for knowledge-driven catalyst design. In this regard, bottom-up synthesis procedures based on colloidal chemistry or atomic layer deposition (ALD) have proven successful in achieving the desired level of control for a variety of fundamental studies. This review aims to give an account of recent progress made in the two aforementioned synthesis techniques for the application of controlled catalytic materials in gas-phase catalysis. For each technique, the focus goes to mono- and bimetallic materials, as well as to recent efforts in enhancing their performance by embedding colloidal templates in porous oxide phases or by the deposition of oxide overlayers via ALD. As a recent extension to the latter, the concept of area-selective ALD for advanced atomic-scale catalyst design is discussed.

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Liu, Jiewei, Lianfen Chen, Hao Cui, Jianyong Zhang, Li Zhang et Cheng-Yong Su. « Applications of metal–organic frameworks in heterogeneous supramolecular catalysis ». Chem. Soc. Rev. 43, n^o 16 (2014) : 6011–61. http://dx.doi.org/10.1039/c4cs00094c.

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Shi, Huancong, Min Huang, Qiming Wu, Linna Zheng, Lifeng Cui, Shuping Zhang et Paitoon Tontiwachwuthikul. « Study of Catalytic CO2 Absorption and Desorption with Tertiary Amine DEEA and 1DMA-2P with the Aid of Solid Acid and Solid Alkaline Chemicals ». Molecules 24, n^o 6 (13 mars 2019) : 1009. http://dx.doi.org/10.3390/molecules24061009.

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Studies of catalytic CO2 absorption and desorption were completed in two well-performed tertiary amines: diethylmonoethanolamine (DEEA) and 1-dimethylamino-2-propanol (1DMA-2P), with the aid of CaCO3 and MgCO3 in the absorption process, and with the aid of γ-Al2O3 and H-ZSM-5 in the desorption process. The batch process was used for CO2 absorption with solid alkalis, and the recirculation process was used for CO2 desorption with solid acid catalysts. The CO2 equilibrium solubility and pKa were also measured at 293 K with results comparable to the literature. The catalytic tests discovered that the heterogeneous catalysis of tertiary amines on both absorption and desorption sides were quite different from monoethanolamine (MEA) and diethanolamine (DEA). These results were illustrative as a start-up to further study of the kinetics of heterogeneous catalysis of CO2 to tertiary amines based on their special reaction schemes and base-catalyzed hydration mechanism.

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Dare, Nicola A., et Timothy J. Egan. « Heterogeneous catalysis with encapsulated haem and other synthetic porphyrins : Harnessing the power of porphyrins for oxidation reactions ». Open Chemistry 16, n^o 1 (15 août 2018) : 763–89. http://dx.doi.org/10.1515/chem-2018-0083.

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AbstractEncapsulated metalloporphyrins have been widely studied for their use as efficient heterogeneous catalysts, inspired by the known catalytic activity of porphyrins in haemoproteins. The oxidation of organic substrates by haemoproteins is one of the well-known roles of these proteins, in which the haem (ferriprotoporphyrin IX = FePPIX) cofactor is the centre of reactivity. While these porphyrins are highly efficient catalysts in the protein environment, once removed, they quickly lose their reactivity. It is for this reason that they have garnered much interest in the field of heterogeneous catalysis of oxidation reactions. This review details current research in the field, focusing on the application of encapsulated haem, and other synthetic metalloporphyrins, applied to oxidation reactions.

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Ji. « Recent Development of Heterogeneous Catalysis in the Transesterification of Glycerol to Glycerol Carbonate ». Catalysts 9, n^o 7 (30 juin 2019) : 581. http://dx.doi.org/10.3390/catal9070581.

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Glycerol is one of the most crucial by-products in the production of biodiesel, and owing to its oversaturation in the market, several synthetic strategies have been developed to transform it into other higher value-added products such as glycerol carbonate, epichlorohydrin, 1,3-propanediol, etc. Amongst them, glycerol carbonate is considered to be the most valuable product. Considering the facile separation and reusability of catalyst, heterogeneous base catalysts have attracted considerable attention due to the obvious advantages over Brϕnsted acid and homogeneous base catalysts in the transesterification of glycerol. Herein, we will give a short overview on the recent development of the heterogeneous catalysis in the transesterification of glycerol with dialkyl carbonate. Focus will be concentrated on the heterogeneous base catalysts including alkaline-earth metal oxides (MgO, CaO, and mixed oxides), hydrotalcites, zeolites, clinoptilolites, organic bases, etc. Their catalytic mechanisms during the heterogeneous process will be elucidated in detail.

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Andrade, Marta A., et Luísa M. D. R. S. Martins. « Sustainability in Catalytic Cyclohexane Oxidation : The Contribution of Porous Support Materials ». Catalysts 10, n^o 1 (18 décembre 2019) : 2. http://dx.doi.org/10.3390/catal10010002.

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The development of green and sustainable protocols for synthetic routes is a growing area of research in chemistry worldwide. The development of sustainable processes and products through innovative catalytic materials and technologies, that allow a better use of resources, is undoubtedly a very important issue facing research chemists today. Environmentally and economically advanced catalytic processes for selective alkane oxidations reactions, as is the case of cyclohexane oxidation, are now focused on catalysts’ stability and their reuse, intending to overcome the drawbacks posed by current homogeneous systems. The aim of this short review is to highlight recent contributions in heterogeneous catalysis regarding porous support materials to be applied to cyclohexane oxidation reaction. Different classes of porous materials are covered, from carbon nanomaterials to zeolites, mesoporous silicas, and metal organic frameworks. The role performed by the materials to be used as supports towards an enhancement of the activity/selectivity of the catalytic materials and the ability of recycling and reuse in consecutive catalytic cycles is highlighted.

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Chassaing, S., V. Bénéteau et P. Pale. « When CuAAC 'Click Chemistry' goes heterogeneous ». Catalysis Science & ; Technology 6, n^o 4 (2016) : 923–57. http://dx.doi.org/10.1039/c5cy01847a.

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Within the green chemistry context, heterogeneous catalysis is more and more applied to organic synthesis. The well known ‘click chemistry’ and especially its flagship, the copper-catalyzed azide–alkyne cycloaddition reaction (CuAAC), is now catch up by such heterogenisation process and copper ions or metals have been grafted or deposited on or into various solids, such as (bio)polymers, charcoal, silica, zeolites, POM or MOF.

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Strekalova, Anna A., Anastasiya A. Shesterkina, Alexander L. Kustov et Leonid M. Kustov. « Recent Studies on the Application of Microwave-Assisted Method for the Preparation of Heterogeneous Catalysts and Catalytic Hydrogenation Processes ». International Journal of Molecular Sciences 24, n^o 9 (5 mai 2023) : 8272. http://dx.doi.org/10.3390/ijms24098272.

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Currently, microwave radiation is widely used in various chemical processes in order to intensify them and carry out processes within the framework of “green” chemistry approaches. In the last 10 years, there has been a significant increase in the number of scientific publications on the application of microwaves in catalytic reactions and synthesis of nanomaterials. It is known that heterogeneous catalysts obtained under microwave activation conditions have many advantages, such as improved catalytic characteristics and stability, and the synthesis of nanomaterials is accelerated several times compared to traditional methods used to produce catalysts. The present review article is to summarize the results of modern research on the use of microwave radiation for the synthesis of heterogeneous catalytic nanomaterials and discusses the prospects for research in the field of microwave-induced liquid-phase heterogeneous catalysis in hydrogenation.

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Manos, Donatos, Kleopatra Miserli et Ioannis Konstantinou. « Perovskite and Spinel Catalysts for Sulfate Radical-Based Advanced Oxidation of Organic Pollutants in Water and Wastewater Systems ». Catalysts 10, n^o 11 (10 novembre 2020) : 1299. http://dx.doi.org/10.3390/catal10111299.

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Since environmental pollution by emerging organic contaminants is one of the most important problems, gaining ground year after year, the development of decontamination technologies of water systems is now imperative. Advanced oxidation processes (AOPs) with the formation of highly reactive radicals can provide attractive technologies for the degradation of organic pollutants in water systems. Among several AOPs that can be applied for the formation of active radicals, this review study focus on sulfate radical based-AOPs (SR-AOPs) through the heterogeneous catalytic activation of persulfate (PS) or peroxymonosulfate (PMS) using perovskite and spinel oxides as catalysts. Perovskites and spinels are currently receiving high attention and being used in substantial applications in the above research area. The widespread use of these materials is based mainly in the possibilities offered by their structure as it is possible to introduce into their structures different metal cations or to partially substitute them, without however destroying their structure. In this way a battery of catalysts with variable catalytic activities can be obtained. Due to the fact that Co ions have been reported to be one of the best activators of PMS, special emphasis has been placed on perovskite/spinel catalysts containing cobalt in their structure for the degradation of organic pollutants through heterogeneous catalysis. Among spinel materials, spinel ferrites (MFe2O4) are the most used catalysts for heterogeneous activation of PMS. Specifically, catalysts with cobalt ion in the A position were reported to be more efficient as PMS activators for the degradation of most organic pollutants compared with other transition metal catalysts. Substituted or immobilized catalysts show high rates of degradation, stability over a wider pH area and also address better the phenomena of secondary contamination by metal leaching, thus an effective method to upgrade catalytic performance.

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Tabasso, Silvia, Emanuela Calcio Gaudino, Elisa Acciardo, Maela Manzoli, Agnese Giacomino et Giancarlo Cravotto. « Microwave-Assisted Dehydrogenative Cross Coupling Reactions in γ-valerolactone with a Reusable Pd/β-cyclodextrin Crosslinked Catalyst ». Molecules 24, n^o 2 (14 janvier 2019) : 288. http://dx.doi.org/10.3390/molecules24020288.

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Transition-metal mediated C–H bond activation and functionalization is one of the most straightforward and powerful tools in modern organic synthetic chemistry. Oxidative C–H/C–H coupling reactions between two (hetero)arenes under heterogeneous catalysis may be a valuable means for the production of a plethora of bi(hetero)aryls, and one that adheres to the increasing demand for atom-economic and sustainable chemistry. We have therefore developed a reusable heterogeneous catalytic system, which is based on Pd cross-linked β-cyclodextrin, to perform an efficient microwave-assisted oxidative C–H/C–H cross coupling process between benzothiazoles and methyl thiophene in the presence of green solvents.

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de la Torre, Alexander F., Gabriel S. Scatena, Oscar Valdés, Daniel G. Rivera et Márcio W. Paixão. « Ugi reaction-derived prolyl peptide catalysts grafted on the renewable polymer polyfurfuryl alcohol for applications in heterogeneous enamine catalysis ». Beilstein Journal of Organic Chemistry 15 (4 juin 2019) : 1210–16. http://dx.doi.org/10.3762/bjoc.15.118.

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The multicomponent synthesis of prolyl pseudo-peptide catalysts using the Ugi reaction with furfurylamines or isocyanides is described. The incorporation of such a polymerizable furan handle enabled the subsequent polymerization of the peptide catalyst with furfuryl alcohol, thus rendering polyfurfuryl alcohol-supported catalysts for applications in heterogeneous enamine catalysis. The utilization of the polymer-supported catalysts in both batch and continuous-flow organocatalytic procedures proved moderate catalytic efficacy and enantioselectivity, but excellent diastereoselectivity in the asymmetric Michael addition of n-butanal to β-nitrostyrene that was used as a model reaction. This work supports the potential of multicomponent reactions towards the assembly of catalysts and their simultaneous functionalization for immobilization.

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Li, Xingxing, Li Fu, Fei Chen, Shichao Zhao, Jiangwei Zhu et Chengliang Yin. « Application of Heterogeneous Catalytic Ozonation in Wastewater Treatment : An Overview ». Catalysts 13, n^o 2 (3 février 2023) : 342. http://dx.doi.org/10.3390/catal13020342.

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Catalytic ozonation is a non-selective mineralization technology of organic matter in water by using active free radicals generated by ozone degradation. Catalytic ozonation technology can be divided into homogeneous catalytic reactions using metal ions as catalysts and heterogeneous catalytic reactions using solid catalysts. Homogeneous catalytic ozonation technology has many problems, such as low mineralization rate, secondary pollution caused by the introduction of metal ions and low utilization efficiency of oxidants, which limit its practical application. Compared with homogeneous catalytic ozonation technology, heterogeneous catalytic ozonation technology has the advantages of easy recovery, lower cost of water treatment, higher activity and improved mineralization rate of organic matter. This overview classifies and describes catalysts for heterogeneous catalytic ozonation technology, including the different types of metal oxides, metal-free catalysts, and substrates used to immobilize catalysts. In addition, the heterogeneous catalytic ozonation process involved in the multiphase complex reaction process is discussed. The effects of different parameters on the performance of heterogeneous catalytic ozonation are also discussed.

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Balloi, Valentina, Manuel Antonio Diaz-Perez, Mayra Anabel Lara-Angulo, David Villalgordo-Hernández, Javier Narciso, Enrique V. Ramos-Fernandez et Juan Carlos Serrano-Ruiz. « Metal–Organic Frameworks as Formose Reaction Catalysts with Enhanced Selectivity ». Molecules 28, n^o 16 (17 août 2023) : 6095. http://dx.doi.org/10.3390/molecules28166095.

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The formose reaction is an autocatalytic series of aldol condensations that allows one to obtain monosaccharides from formaldehyde. The formose reaction suffers from a lack of selectivity, which hinders practical applications at the industrial level. Over the years, many attempts have been made to overcome this selectivity issue, with modest results. Heterogeneous porous catalysts with acid–base properties, such as Metal–Organic Frameworks (MOFs), can offer advantages compared to homogeneous strong bases (e.g., calcium hydroxide) for increasing the selectivity of this important reaction. For the very first time, four different Zeolite Imidazolate Frameworks are presented in this work as catalysts for the formose reaction in liquid phase, and their catalytic performances were compared with those of the typical homogeneous catalyst (i.e., calcium hydroxide). The heterogeneous nature of the catalysis, the possible contribution of leached metal or linkers to the solution, and the stability of the materials were investigated. The porous structure of these solids and their mild basicity make them suitable for obtaining enhanced selectivity at 30% formaldehyde conversion. Most of the MOFs tested showed low structural stability under reaction conditions, thereby indicating the need to search for new MOF families with higher robustness. However, this important result opens the path for future research on porous heterogeneous basic catalysts for the formose reaction.

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Kholdeeva, Oxana, et Nataliya Maksimchuk. « Metal-Organic Frameworks in Oxidation Catalysis with Hydrogen Peroxide ». Catalysts 11, n^o 2 (21 février 2021) : 283. http://dx.doi.org/10.3390/catal11020283.

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In recent years, metal–organic frameworks (MOFs) have received increasing attention as selective oxidation catalysts and supports for their construction. In this short review paper, we survey recent findings concerning use of MOFs in heterogeneous liquid-phase selective oxidation catalysis with the green oxidant–aqueous hydrogen peroxide. MOFs having outstanding thermal and chemical stability, such as Cr(III)-based MIL-101, Ti(IV)-based MIL-125, Zr(IV)-based UiO-66(67), Zn(II)-based ZIF-8, and some others, will be in the main focus of this work. The effects of the metal nature and MOF structure on catalytic activity and oxidation selectivity are analyzed and the mechanisms of hydrogen peroxide activation are discussed. In some cases, we also make an attempt to analyze relationships between liquid-phase adsorption properties of MOFs and peculiarities of their catalytic performance. Attempts of using MOFs as supports for construction of single-site catalysts through their modification with heterometals will be also addressed in relation to the use of such catalysts for activation of H2O2. Special attention is given to the critical issues of catalyst stability and reusability. The scope and limitations of MOF catalysts in H2O2-based selective oxidation are discussed.

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Noriega, Saúl, Elisa Leyva, Edgar Moctezuma, Luisa Flores et Silvia Loredo-Carrillo. « Recent Catalysts Used in the Synthesis of 1,4-Disubstituted 1,2,3-Triazoles by Heterogeneous and Homogeneous Methods ». Current Organic Chemistry 24, n^o 5 (17 mai 2020) : 536–49. http://dx.doi.org/10.2174/1385272824666200226120135.

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1,2,3-triazoles are popular heterocycles employed in material sciences and medicinal chemistry as they show antiviral, antibacterial, anti-HIV, antitubercular, and antifungal activities. Triazoles are appealing due to their stability and interesting click chemistry properties. The Cu(I) catalyzed reaction between azides and alkynes affords the 1,4- disubstituted derivative exclusively becoming a useful synthetic tool. However, one of the main drawbacks of the catalyzed reaction is the need to use Cu(I), which is unstable at standard conditions and rapidly oxidizes to the non-active Cu(II). The most common approach when synthesizing 1,4-disubstituted-1,2,3-triazoles is to reduce Cu in situ employing inorganic Cu salts and a reducing agent. The resulting Cu(I) needs to be further stabilized with organic ligands for the reaction to take place. The aim of homogeneous catalysis is to produce a ligand with a dual function both in reducing and stabilizing Cu(I) without interfering in the overall reaction. Instead, heterogeneous catalysis offers more options when supporting Cu on nanoparticles, complexes, and composites yielding the desired 1,2,3-triazoles in most cases without the need of a reducing agent under green solvents such as ethanol and water. The catalytic activity of Ag, Ru, and Ce is also discussed. This review exemplifies how the use of homogeneous and heterogeneous catalysts offers new and green methodologies for the synthesis of 1,2,3-triazole derivatives. The materials supporting Cu show catalytic properties like high surface area, acid-base sites or phase transfer. Although there is no ideal catalyst, Cu remains the most effective metal since it is economical, abundant and readily available.

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Sebati, Wilhemina, et Suprakas Ray. « Advances in Nanostructured Metal-Encapsulated Porous Organic-Polymer Composites for Catalyzed Organic Chemical Synthesis ». Catalysts 8, n^o 11 (24 octobre 2018) : 492. http://dx.doi.org/10.3390/catal8110492.

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Porous organic polymers (POPs) are of growing research interest owing to their high surface areas, stabilities, controllable chemical configurations, and tunable pore volumes. The molecular nanoarchitecture of POP provides metal or metal oxide binding sites, which is promising for the development of advanced heterogeneous catalysts. This article highlights the development of numerous kinds of POPs and key achievements to date, including their functionalization and incorporation of nanoparticles into their framework structures, characterization methods that are predominantly in use for POP-based materials, and their applications as catalysts in several reactions. Scientists today are capable of preparing POP-based materials that show good selectivity, activity, durability, and recoverability, which can help overcome many of the current environmental and industrial problems. These POP-based materials exhibit enhanced catalytic activities for diverse reactions, including coupling, hydrogenation, and acid catalysis.

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Trigoura, Leslie, Yalan Xing et Bhanu P. S. Chauhan. « Recyclable Catalysts for Alkyne Functionalization ». Molecules 26, n^o 12 (9 juin 2021) : 3525. http://dx.doi.org/10.3390/molecules26123525.

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In this review, we present an assessment of recent advances in alkyne functionalization reactions, classified according to different classes of recyclable catalysts. In this work, we have incorporated and reviewed the activity and selectivity of recyclable catalytic systems such as polysiloxane-encapsulated novel metal nanoparticle-based catalysts, silica–copper-supported nanocatalysts, graphitic carbon-supported nanocatalysts, metal organic framework (MOF) catalysts, porous organic framework (POP) catalysts, bio-material-supported catalysts, and metal/solvent free recyclable catalysts. In addition, several alkyne functionalization reactions have been elucidated to demonstrate the success and efficiency of recyclable catalysts. In addition, this review also provides the fundamental knowledge required for utilization of green catalysts, which can combine the advantageous features of both homogeneous (catalyst modulation) and heterogeneous (catalyst recycling) catalysis.

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Salubi, Christiana Abimbola. « Heterogeneous vanadium Schiff base complexes in catalytic oxidation reactions ». Current Chemistry Letters 12, n^o 1 (2023) : 91–106. http://dx.doi.org/10.5267/j.ccl.2022.9.003.

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The chemistry of Schiff base has received remarkable attention in different applications, both organic synthesis and industries. Over the past few years many reports have been on the synthesis, characterization and application of vanadium Schiff base complexes. However, heterogeneous vanadium Schiff base catalysts are active for various oxidation reactions, making catalytic oxidation of hydrocarbons a great interest. This review summarizes the recent development of organic substrate oxidation with heterogeneous vanadium Schiff base catalysts.

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Zhang, Zhenwei, Xiaochen Shen, Ziping Li, Si Ma, Hong Xia et Xiaoming Liu. « Multifunctional chiral cationic porous organic polymers : gas uptake and heterogeneous asymmetric organocatalysis ». Polymer Chemistry 12, n^o 23 (2021) : 3367–74. http://dx.doi.org/10.1039/d1py00242b.

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Chiral porous organic polymers are characterized by robust, non-toxic and recyclable properties. Therefore, compared with small molecular catalysts, they have attracted much attention in the field of heterogeneous asymmetric organic catalysis.

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Dong, Zhun, Ahmad Mukhtar et Hongfei Lin. « Heterogeneous Catalysis on Liquid Organic Hydrogen Carriers ». Topics in Catalysis 64, n^o 7-8 (27 mai 2021) : 481–508. http://dx.doi.org/10.1007/s11244-021-01458-5.

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Mayer-Gall, Thomas, Ji-Woong Lee, Klaus Opwis, Benjamin List et Jochen S. Gutmann. « Textile Catalysts-An unconventional approach towards heterogeneous catalysis ». ChemCatChem 8, n^o 8 (24 mars 2016) : 1428–36. http://dx.doi.org/10.1002/cctc.201501252.

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Nath, Ipsita, Jeet Chakraborty, Sara Abednatanzi et Pascal Van Der Voort. « A ‘Defective’ Conjugated Porous Poly-Azo as Dual Photocatalyst ». Catalysts 11, n^o 9 (31 août 2021) : 1064. http://dx.doi.org/10.3390/catal11091064.

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A heterogeneous photocatalyst amenable to catalyze different chemical reactions is a highly enabling and sustainable material for organic synthesis. Herein we report the synthesis and characterization of an azobenzene-based organic π–conjugated porous polymer (AzoCPP) as heterogeneous dual photocatalyst manifesting net-oxidative bromination of arenes and dehydroxylation of boronic acids to corresponding phenols. Hierarchical porosity and high surface area of the nano-sized AzoCPP allowed superior catalyst-substrate contact during catalyses, whereas the inherent structural defect present in the CPP backbone resulted in low-energy sinks functioning as de facto catalytic sites. A combination of these two structure-property aspects of AzoCPP, in addition to the dielectric constant manipulation of the system, led to excellent catalytic performance. The protocols remained valid for a wide substrate scope and the catalyst was recycled multiple times without substantial loss in catalytic activity. With the aid of subsequent control experiments and analytical characterizations, mechanisms for each catalysis are proposed and duly corroborated.

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Buaki-Sogó, Mireia, Leire Zubizarreta, Marta García-Pellicer et Alfredo Quijano-López. « Sustainable Carbon as Efficient Support for Metal-Based Nanocatalyst : Applications in Energy Harvesting and Storage ». Molecules 25, n^o 14 (8 juillet 2020) : 3123. http://dx.doi.org/10.3390/molecules25143123.

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Sustainable activated carbon can be obtained from the pyrolysis/activation of biomass wastes coming from different origins. Carbon obtained in this way shows interesting properties, such as high surface area, electrical conductivity, thermal and chemical stability, and porosity. These characteristics among others, such as a tailored pore size distribution and the possibility of functionalization, lead to an increased use of activated carbons in catalysis. The use of activated carbons from biomass origins is a step forward in the development of more sustainable processes enhancing material recycling and reuse in the frame of a circular economy. In this article, a perspective of different heterogeneous catalysts based on sustainable activated carbon from biomass origins will be analyzed focusing on their properties and catalytic performance for determined energy-related applications. In this way, the article aims to give the reader a scope of the potential of these tailor-made sustainable materials as a support in heterogeneous catalysis and future developments needed to improve catalyst performance. The selected applications are those related with H2 energy and the production of biomethane for energy through CO2 methanation.

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Song, Kyung Seob, et Ali Coskun. « Porous Organic Polymers for Selective Palladium Recovery and Heterogeneous Catalysis ». CHIMIA 77, n^o 3 (29 mars 2023) : 122. http://dx.doi.org/10.2533/chimia.2023.122.

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Palladium (Pd) recycling from waste materials is an important approach in order to meet the growing demand for Pd originating from its broad range of applications including automotive industry, electronics and catalysis. In this article, we discuss the design principles of solid-sorbents for efficient recovery of Pd from waste sources with a particular emphasis on porous organic polymers (POPs), which emerged as promising porous materials for Pd recovery due to their tunable chemical functionality, stability and porosity. We discuss the critical role of binding sites and porosity in the Pd uptake capacity, adsorption kinetics and selectivity. We also highlight the use of captured Pd within the polymer networks as heterogeneous catalysts for cross-coupling reactions.

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Li, Chunxia, Dandan Zhong, Xianqiang Huang, Guodong Shen, Qiang Li, Jiyuan Du, Qianli Li, Suna Wang, Jikun Li et Jianmin Dou. « Two organic–inorganic hybrid polyoxovanadates as reusable catalysts for Knoevenagel condensation ». New Journal of Chemistry 43, n^o 15 (2019) : 5813–19. http://dx.doi.org/10.1039/c8nj06460a.

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Two novel polyoxovanadates as heterogeneous catalysts have exhibited excellent catalytic properties in the Knoevenagel condensation, especially compound 1's activity is basically maintained after three cycles.

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Lazzarini, Andrea, Roberta Colaiezzi, Francesco Gabriele et Marcello Crucianelli. « Support–Activity Relationship in Heterogeneous Catalysis for Biomass Valorization and Fine-Chemicals Production ». Materials 14, n^o 22 (11 novembre 2021) : 6796. http://dx.doi.org/10.3390/ma14226796.

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Heterogeneous catalysts are progressively expanding their field of application, from high-throughput reactions for traditional industrial chemistry with production volumes reaching millions of tons per year, a sector in which they are key players, to more niche applications for the production of fine chemicals. These novel applications require a progressive utilization reduction of fossil feedstocks, in favor of renewable ones. Biomasses are the most accessible source of organic precursors, having as advantage their low cost and even distribution across the globe. Unfortunately, they are intrinsically inhomogeneous in nature and their efficient exploitation requires novel catalysts. In this process, an accurate design of the active phase performing the reaction is important; nevertheless, we are often neglecting the importance of the support in guaranteeing stable performances and improving catalytic activity. This review has the goal of gathering and highlighting the cases in which the supports (either derived or not from biomass wastes) share the worth of performing the catalysis with the active phase, for those reactions involving the synthesis of fine chemicals starting from biomasses as feedstocks.

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Cottone, Grazia, Sergio Giuffrida, Stefano Bettati, Stefano Bruno, Barbara Campanini, Marialaura Marchetti, Stefania Abbruzzetti et al. « More than a Confinement : “Soft” and “Hard” Enzyme Entrapment Modulates Biological Catalyst Function ». Catalysts 9, n^o 12 (4 décembre 2019) : 1024. http://dx.doi.org/10.3390/catal9121024.

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Catalysis makes chemical and biochemical reactions kinetically accessible. From a technological point of view, organic, inorganic, and biochemical catalysis is relevant for several applications, from industrial synthesis to biomedical, material, and food sciences. A heterogeneous catalyst, i.e., a catalyst confined in a different phase with respect to the reagents’ phase, requires either its physical confinement in an immobilization matrix or its physical adsorption on a surface. In this review, we will focus on the immobilization of biological catalysts, i.e., enzymes, by comparing hard and soft immobilization matrices and their effect on the modulation of the catalysts’ function. Indeed, unlike smaller molecules, the catalytic activity of protein catalysts depends on their structure, conformation, local environment, and dynamics, properties that can be strongly affected by the immobilization matrices, which, therefore, not only provide physical confinement, but also modulate catalysis.

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Zhang, Shaowei, Fuxia Ou, Shiggang Ning et Peng Cheng. « Polyoxometalate-based metal–organic frameworks for heterogeneous catalysis ». Inorganic Chemistry Frontiers 8, n^o 7 (2021) : 1865–99. http://dx.doi.org/10.1039/d0qi01407a.

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Karakhanov, Eduard, Anton Maximov et Anna Zolotukhina. « Heterogeneous Dendrimer-Based Catalysts ». Polymers 14, n^o 5 (28 février 2022) : 981. http://dx.doi.org/10.3390/polym14050981.

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The present review compiles the advances in the dendritic catalysis within the last two decades, in particular concerning heterogeneous dendrimer-based catalysts and their and application in various processes, such as hydrogenation, oxidation, cross-coupling reactions, etc. There are considered three main approaches to the synthesis of immobilized heterogeneous dendrimer-based catalysts: (1) impregnation/adsorption on silica or carbon carriers; (2) dendrimer covalent grafting to various supports (silica, polystyrene, carbon nanotubes, porous aromatic frameworks, etc.), which may be performed in a divergent (as a gradual dendron growth on the support) or convergent way (as a grafting of whole dendrimer to the support); and (3) dendrimer cross-linking, using transition metal ions (resulting in coordination polymer networks) or bifunctional organic linkers, whose size, polarity, and rigidity define the properties of the resulted material. Additionally, magnetically separable dendritic catalysts, which can be synthesized using the three above-mentioned approaches, are also considered. Dendritic catalysts, synthesized in such ways, can be stored as powders and be easily separated from the reaction medium by filtration/centrifugation as traditional heterogeneous catalysts, maintaining efficiency as for homogeneous dendritic catalysts.

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Tang, Fushun, John C. G. Zhao et Banglin Chen. « Porous Coordination Polymers for Heterogeneous Catalysis ». Current Organic Chemistry 22, n^o 18 (22 octobre 2018) : 1773–91. http://dx.doi.org/10.2174/1385272822666180827143018.

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Peng, Ling, Shujie Wu, Xiaoyuan Yang, Jing Hu, Xiaoran Fu, Qisheng Huo et Jingqi Guan. « Application of metal organic frameworks M(bdc)(ted)0.5 (M = Co, Zn, Ni, Cu) in the oxidation of benzyl alcohol ». RSC Advances 6, n^o 76 (2016) : 72433–38. http://dx.doi.org/10.1039/c6ra12799a.

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Yu, Wei, Minghong Zhou, Tianqi Wang, Zidong He, Buyin Shi, Yang Xu et Kun Huang. « “Click Chemistry” Mediated Functional Microporous Organic Nanotube Networks for Heterogeneous Catalysis ». Organic Letters 19, n^o 21 (26 octobre 2017) : 5776–79. http://dx.doi.org/10.1021/acs.orglett.7b02682.

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John, Jubi, Edmond Gravel, Irishi N. N. Namboothiri et Eric Doris. « Advances in carbon nanotube-noble metal catalyzed organic transformations ». Nanotechnology Reviews 1, n^o 6 (1 décembre 2012) : 515–39. http://dx.doi.org/10.1515/ntrev-2012-0025.

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AbstractThis review article is dealing with heterogeneous catalysis applied to synthetic chemistry using various carbon nanotube-supported noble metals (e.g., ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold).

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Córdova, Armando. « Combined heterogeneous metal/organic catalysts for eco-friendly synthesis ». Pure and Applied Chemistry 87, n^o 9-10 (1 octobre 2015) : 1011–19. http://dx.doi.org/10.1515/pac-2015-0405.

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AbstractThe interplay and synergistic cooperation between homogeneous and heterogeneous catalyst systems is of utmost importance in nature. It is also applied in chemical synthesis. Here, it can allow for new reactivity, which is not possible by the employment of a single catalyst, and promote the catalysis of multiple transformations in a one-pot sequence. This could overall lead to novel reactions and the development of sustainable chemistry. In this context, a versatile and broad synergistic strategy for the selective synthesis of valuable molecules with variable complexity and under eco-friendly conditions is disclosed. It is based on integrated heterogeneous metal/organo multiple relay catalysis, which is performed in a single reaction vessel, and allows for the assembly of complex molecules (e.g., heterocycles and carbocycles) with up to three quaternary stereocenters in a highly enantioselective fashion from simple alcohols and air/O2.

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