PH-Driven Hydrothermal Synthesis of Leiteite ZnAs 2 O 4 : Structure, Characterization, and Multifunctional Applications including Photocatalytic Dye Degradation, Catalytic Organic Transformation, and Antibacterial and Antioxidant Properties

A review of ionic liquids: Applications towards catalytic organic transformations

The development of green, sustainable and economical chemical processes is one of the major challenges in chemistry. Besides the traditional need for efficient and selective catalytic reactions that will transform raw materials into valuable chemicals, pharmaceuticals and fuels, green chemistry also strives for waste reduction, atomic efficiency and high rates of catalyst recovery. Nanostructured materials are attractive candidates as heterogeneous catalysts for various organic transformations, especially because they meet the goals of green chemistry. Researchers have made significant advances in the synthesis of well-defined nanostructured materials in recent years. Among these are novel approaches that have permitted the rational design and synthesis of highly active and selective nanostructured catalysts by controlling the structure and composition of the active nanoparticles (NPs) and by manipulating the interaction between the catalytically active NP species and their support. The ease of isolation and separation of the heterogeneous catalysts from the desired organic product and the recovery and reuse of these NPs further enhance their attractiveness as green and sustainable catalysts. This Account reviews recent advances in the use of nanostructured materials for catalytic organic transformations. We present a broad overview of nanostructured catalysts used in different types of organic transformations including chemoselective oxidations and reductions, asymmetric hydrogenations, coupling reactions, C-H activations, oxidative aminations, domino and tandem reactions, and more. We focus on recent research efforts towards the development of the following nanostructured materials: (i) nanostructured catalysts with controlled morphologies, (ii) magnetic nanocomposites, (iii) semiconductor-metal nanocomposites, and (iv) hybrid nanostructured catalysts. Selected examples showcase principles of nanoparticle design such as the enhancement of reactivity, selectivity and/or recyclability of the nanostructured catalysts via control of the structure, composition of the catalytically active NPs, and/or nature of the support. These principles will aid researchers in the rational design and engineering of new types of multifunctional nanocatalysts for the achievement of green and sustainable chemical processes. Although the past decade has brought many advances, there are still challenges in the area of nanocatalysis that need to be addressed. These include loss of catalytic activity during operation due to sintering, leaching of soluble species from the nanocatalysts under harsh reaction conditions, loss of control over well-defined morphologies during the scale-up synthesis of the nanocomposites, and limited examples of enantioselective nanocatalytic systems. The future of nanocatalyst research lies in the judicious design and development of nanocomposite catalysts that are stable and resistant to sintering and leaching, and yet are highly active and enantioselective for the desired catalytic organic transformations, even after multiple runs. The successful generation of such multifunctional nanocatalysts especially in tandem, domino, or cascade reactions would provide a powerful tool for the establishment of green and sustainable technologies.

The organometallic chemistry of nickel has experienced rapid growth over the past decade. A number of exciting new areas have emerged, such as the reactivities of Ni(0)‐carbene complexes and the polymerization of olefins catalyzed by nickel complexes of nitrogen‐based ligands. In addition, the traditionally rich area of Ni‐catalyzed organic transformations has undergone major developments that have expanded the scope of their applications. These are the subjects of the present chapter. Among the topics that will be discussed are the preparation, characterization, and reactivity studies of nickel complexes of allyl, cyclopentadienly, indenyl, and tris(pyrazolyl)borate ligands. The main structural and bonding properties of these complexes are presented and their major reactivities are outlined. Another topic of importance is the chemistry of the nickel complexes of hydride, alkyl, alkenyl, and silyl ligands. Hydrido and alkyl complexes of nickel are often involved in many catalytic processes of commercial importance, and so an in‐depth understanding of the fundamental reactivities of these complexes is crucial to expanding their practical applications. Silyl complexes are involved in the transformations of organosilicon compounds, and for this reason their basic reactivities and structural properties are of interest. Zerovalent nickel complexes are also very important in the catalytic organic transformations. One of the most exciting developments in this area is the recent introduction of N‐heterocyclic carbene ligands. Ni complexes of these ligands have been shown to be important catalysts and reagents for a number of important organic transformations. Some of the practical methods for preparing Ni‐carbene complexes will be outlined, and the recently reported catalytic reactions promoted by these complexes will be described. One of the most important areas of growth for the chemistry of nickel has been the polymerization and copolymerization of olefins. Thus, this chapter will describe the discovery of a family of diimine complexes that catalyze the polymerization of aliphatic olefins. A series of new and highly efficient catalysts were introduced in rapid progression, a great deal of new chemistry has been discovered, and a number of industrial processes have been developed on the basis of these nickel complexes. We will also discuss the emergence of new strategies for the efficient cross‐coupling of alkyl halides with organozinc and Grignard reagents, as well as the coupling of dienes with CO 2 .

The organometallic chemistry of nickel has experienced rapid growth over the past decade. A number of exciting new areas have emerged, such as the reactivities of Ni(0)‐carbene complexes and the polymerization of olefins catalyzed by nickel complexes of nitrogen‐based ligands. In addition, the traditionally rich area of Ni‐catalyzed organic transformations has undergone major developments that have expanded the scope of their applications. These are the subjects of the present chapter. Among the topics that will be discussed are the preparation, characterization, and reactivity studies of nickel complexes of allyl, cyclopentadienly, indenyl, and tris(pyrazolyl)borate ligands. The main structural and bonding properties of these complexes are presented and their major reactivities are outlined. Another topic of importance is the chemistry of the nickel complexes of hydride, alkyl, alkenyl, and silyl ligands. Hydrido and alkyl complexes of nickel are often involved in many catalytic processes of commercial importance, and so an in‐depth understanding of the fundamental reactivities of these complexes is crucial to expanding their practical applications. Silyl complexes are involved in the transformations of organosilicon compounds, and for this reason their basic reactivities and structural properties are of interest. Zerovalent nickel complexes are also very important in the catalytic organic transformations. One of the most exciting developments in this area is the recent introduction of N‐heterocyclic carbene ligands. Ni complexes of these ligands have been shown to be important catalysts and reagents for a number of important organic transformations. Some of the practical methods for preparing Ni‐carbene complexes will be outlined, and the recently reported catalytic reactions promoted by these complexes will be described. One of the most important areas of growth for the chemistry of nickel has been the polymerization and copolymerization of olefins. Thus, this chapter will describe the discovery of a family of diimine complexes that catalyze the polymerization of aliphatic olefins. A series of new and highly efficient catalysts were introduced in rapid progression, a great deal of new chemistry has been discovered, and a number of industrial processes have been developed on the basis of these nickel complexes. We will also discuss the emergence of new strategies for the efficient cross‐coupling of alkyl halides with organozinc and Grignard reagents, as well as the coupling of dienes with CO 2 .

Recent advances in graphene oxide catalyzed organic transformations

The use of carbonized materials derived from metal–organic frameworks (MOFs) in catalytic organic transformations is less well explored than is the use of MOFs. Here, we survey the oxidative performance of heterogeneous catalyst materials derived from the polycrystalline iron–organic framework TAL-1.

Naked magnetic nanoparticles are successfully used as magnetically recoverable catalysts for organic transformations; this review highlights recent progress in this rapidly growing field.

Half-sandwich arene ruthenium complexes exhibit versatile chemistry, serve as excellent precursors and find potential applications in many organic transformations. This review mainly focuses on the chemistry of piano-stool ruthenium complexes with special emphasis on the achiral or chiral-at-ruthenium center. Also, it deals with the synthesis, nomenclature and stereochemistry of arene ruthenium complexes along with mechanistic insights into the epimerization reactions and their applications in catalytic organic transformations with some selected examples.

N-heterocyclic silylenes as powerful steering ligands in catalysis

In cutting-edge organic synthesis, the creation of sustainable catalytic systems occupies center stage, especially in light of the growing need for environmentally friendly and energy-efficient procedures. FeVO4 is a triclinic, n-type semiconductor that has been studied for a variety of uses, such as photocatalytic hydrogen generation, zinc batteries, photodegradation, and catalytic reactions. FeVO4 is a pertinent semiconductor since it is stable, chemically unreactive, nontoxic, and attainable. FeVO4 has attracted the attention of researchers due to its stable chemical properties, reduced band gap, and lower cost compared to InVO4 and BiVO4. As a result, an increasing number of metal vanadates with strong catalytic and photocatalytic activities have been discovered and described. We primarily focused on the catalytic organic transformations in the presence of FeVO4 and its nanocomposites. The review presents a thorough grasp of the ways that FeVO4 nanocomposites might aid in the creation of more environmentally friendly and effective catalytic systems for organic synthesis, while also addressing the field’s challenges, obstacles and future prospects. Our current evaluation efforts are expected to shed light on the future path of FeVO4 nano catalysts.

Review: 126 refs.

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTRecent Advances in High Oxidation State Mo and W Imido Alkylidene ChemistryRichard R. Schrock*View Author Information Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139* To whom correspondence should be addressed. E-mail: [email protected]Cite this: Chem. Rev. 2009, 109, 8, 3211–3226Publication Date (Web):March 13, 2009Publication History Received28 October 2008Published online13 March 2009Published inissue 12 August 2009https://pubs.acs.org/doi/10.1021/cr800502phttps://doi.org/10.1021/cr800502preview-articleACS PublicationsCopyright © 2009 American Chemical SocietyRequest reuse permissionsArticle Views8593Altmetric-Citations381LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Catalysts,Hydrocarbons,Ligands,Metals,Metathesis Get e-Alerts

Heterogeneous catalysis represents one of the important areas in the field of organic synthesis. Major developments have been emerged during last few decades and polymer-supported catalysts have been employed successfully in various catalytic organic transformations. Ion-exchange resins and polypeptides are two important examples of such heterogeneous polymer-supported catalysts among others because of their easy accessibility, stability, recoverability and reusability. Cross-linked ion-exchange resins and polypeptides are highly insoluble, which make them better choice in terms of their easy separation from the reaction mixture and subsequent recyclability. The present review article provides an overview of different types of ion exchange resins as polymer-supported catalysts such as amberlite resin, polystyrene resin, polyionic gel-based systems, ion-exchange resins and prolineimmobilized species, PEG-bound poly (amino acid), amino acid anchored with Merrifild resin, amphiphilic block polypeptides etc. Their preparation, characterizations and catalytic applications in diverse organic transformations have been presented with critical analysis on their stability, mechanistic overview and suitability etc.

N‐heterocyclic carbene (NHC) complexes of gold(I/III) attained immense interest in catalytic organic transformations and as anticancer agents against several types of human cancers; however, their potential as electrocatalysts is scarce. The electrocatalytic oxygen evolution reaction was performed for the first time using pyridine‐functionalized NHC gold(I) binuclear metallacycles (8 and 9) possessing aptly designed ligand field. Complexes were prepared by the transmetallation of corresponding silver(I) NHC complexes, which were prepared by in situ deprotonation of pyridine and aryl substituted 1,2,4‐triazolium hexafluorophosphate salts (6 and 7) with Ag2O under dark. Both triazolium salts and binuclear gold(I) metallacycles were thoroughly characterised by NMR and ATR‐IR spectral and elemental analyses. A bromide salt 4 and a binuclear gold complex 9 were elucidated for structure by single crystal X‐ray diffraction analysis. Complex 9 possesses distorted linear coordination geometry around the gold atoms by the coordination of carbene carbon and pyridine nitrogen atoms bearing close Au–Au interaction (3.251 Å). The binuclear gold complexes 8 and 9 (along with 10 wt% conductive mesoporous carbon) were investigated as molecular electrocatalysts in oxygen evolution reaction (OER), which evidenced an oxygen evolution overpotential of 2.422 and 2.370 V versus reversible hydrogen electrode (RHE), respectively, to attain a current density of 10 mA.cm−2. The Tafel slope values of 40.9 and 30.4 mV dec−1 for 8 and 9, respectively, indicate the reaction mechanism involved and the suitability of these complexes as apt electrocatalysts for OER. The stability of the prepared molecular electrocatalysts was investigated by cyclic voltammetry and chronoamperometry techniques.

Nanostructured metal (Fe, Co, Mn, Cr, Mo) oxides were fabricated under microwave irradiation conditions in pure water without using any reducing or capping reagent. The metal oxides self-assembled into octahedra, spheres, triangular rods, pine, and hexagonal snowflake-like three-dimensional morphologies. Pine-structured nano-iron oxides were studied as a novel support for various catalytic organic transformations.