Catalysts In Organic Synthesis Research Articles

Molybdenum Disulfide-Based Catalysts in Organic Synthesis: State of the Art, Open Issues, and Future Perspectives.

In the field of heterogeneous organic catalysis, molybdenum disulfide (MoS2) is gaining increasing attention as a catalytically active material due to its low toxicity, earth abundance, and affordability. Interestingly, the catalytic properties of this metal-based material can be improved by several strategies. In this Perspective, through the analysis of some explicative examples, the main approaches used to prepare highly efficient MoS2-based catalysts in relevant organic reactions are summarized and critically discussed, namely: i) increment of the specific surface area, ii) generation of the metallic 1T phase, iii) introduction of vacancies, iv) preparation of nanostructured hybrids/composites, v) doping with transition metal ions, and vi) partial oxidation of MoS2. Finally, emerging trends in MoS2-based materials catalysis leading to a richer organic synthesis are presented.

Recent Advances in Scandium(III) Triflate Catalysis: A Review

AbstractOver the past three decades, triflate salts have emerged as crucial Lewis acid catalysts in organic synthesis, playing a significant role in cyclization, C−H bond functionalization, and various other reactions. Among these, rare‐earth triflates have garnered attention due to their water compatibility, environmental friendliness, noncorrosive nature, and reusability. In particular, scandium(III) triflate [Sc(OTf)3] stands out as a water‐resistant Lewis acid with remarkable catalytic activity in aqueous environments. Unlike typical Lewis acids such as AlCl3, BF3, and SnCl4, which are decomposed or deactivated by water, Sc(OTf)3 remains stable and effective. Its exceptional Lewis acidity, resilience against hydrolysis, and recyclability make it a prominent green catalyst. The unique stability of Sc(OTf)3 in water is attributed to the smaller size of scandium ions (Sc3+), enhancing its catalytic efficiency. Sc(OTf)3 has a longstanding history in organic synthesis, facilitating a wide range of reactions including aldol, Michael, allylation, Friedel‐Crafts acylations, Diels‐Alder, Mannich, cycloadditions (including cyclopropanation), and cascade reactions. The increasing utilization of Sc(OTf)3 over the past decade underscores the necessity for updated insights. This review provides a concise overview of the versatility of Sc(OTf)3 as a catalyst, focusing on developments from 2017 to 2024.

Zirconium/niacin metal-organic framework preparation, characterization and assessment as a catalyst in one-pot synthesis of xanthene-1,8-dione derivatives with docking validation as anti-inflammatory

The zirconium/niacin metal-organic framework (MOF) was prepared by an efficient solvothermal method and the nanostructure of MOF was identified by IR, SEM, EDX, XRD, BET and TEM. The prepared Zr-MOF was evaluated as a catalyst in organic synthesis. Tetrahydro xanthene-1,8‑dione derivatives were synthesized by a one-pot reaction between 2 mol of dimedone and 1 mole of aromatic aldehyde in the presence of the catalytic amount of Zr-MOF under solvent-free conditions. The prepared ligands were evaluated as COX-1 and COX-2 inhibitors and the data obtained explained that the ligands 4-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenyl benzoate (3 g), 3,3,6,6-tetramethyl-9-(5-methylfuran-2-yl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)‑dione (3i) and 9-(3-(4-chlorophenyl)-1-phenyl-1H-pyrazol-4-yl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)‑dione (3j) gave the promised data.

Recent advances in the synthesis of highly substituted imidazolidines.

Imidazolidine is a saturated heterocycle with a cyclic aminal core that can be found in natural products and biologically active molecules. Additionally, these heterocyclic compounds have been utilized as chiral ligands, N-heterocyclic carbene precursors, and catalysts in organic synthesis. This review is an attempt to compile the literature of various synthetic procedures of highly substituted imidazolidines, chiral imidazolidines with high diastereoselectivities and enantioselectivities, bis-imidazolidines, and spiro-imidazolidines, as well as their pharmacological properties during the period from 1949 to 2023.

Advancing Heterogeneous Organic Synthesis With Coordination Chemistry-Empowered Single-Atom Catalysts.

For traditional metal complexes, intricate chemistry is required to acquire appropriate ligands for controlling the electron and steric hindrance of metal active centers. Comparatively, the preparation of single-atom catalysts is much easier with more straightforward and effective accesses for the arrangement and control of metal active centers. The presence of coordination atoms or neighboring functional atoms on the supports' surface ensures the stability of metal single-atoms and their interactions with individual metal atoms substantially regulate the performance of metal active centers. Therefore, the collaborative interaction between metal and the surrounding coordination environment enhances the initiation of reaction substrates and the formation and transformation of crucial intermediate compounds, which imparts single-atom catalysts with significant catalytic efficacy, rendering them a valuable framework for investigating the correlation between structure and activity, as well as the reaction mechanism of catalysts in organic reactions. Herein, comprehensive overviews of the coordination interaction for both homogeneous metal complexes and single-atom catalysts in organic reactions are provided. Additionally, reflective conjectures about the advancement of single-atom catalysts in organic synthesis are also proposed to present as a reference for later development.

The Direct Use of Metallic Ore Minerals as Catalysts in Organic Syntheses

The Direct Use of Metallic Ore Minerals as Catalysts in Organic Syntheses

Design of Dendritic Foldamers as Catalysts for Organic Synthesis

Background:: Multistranded foldamers mimic biopolymer architecture, through the assembly and folding of intrinsically flexible polymeric chains attached to polyol core have been synthesised here. The synthesised dendritic motifs possess helical cavities with properly arranged active sites. As these cavities are large enough to accommodate guest molecules, their application as synthetic foldamer catalyst were investigated in Knoevenagel and Mannich reactions. Methods:: It is presumed to be the potentiality of dendritic foldamers to form reverse micelle in the interior of helical motif containing many reactive sites. Results:: Inside the dendritic foldamer, the substrates are adequately concentrated, work together in cooperation for ligand-binding, and stabilize the transition state as in enzymes that helps to accelerate the reaction rate many times greater than in bulk solution. Conclusion:: An unrivalled reaction rate and high yield of products were obtained within a short time in both Knoevenagel and Mannich reactions by using dendritic foldamers as catalysts.

Zintl Clusters as a Platform for Lewis Acid Catalysis.

Clusters of the main group elements phosphorus and arsenic, commonly categorized as Zintl clusters, have been known for over a century. And, only now is the application of these systems as catalysts for organic synthesis being investigated. In this work, boranes are tethered via an aliphatic linker to Zintl-based clusters and their Lewis acidity is examined experimentally, by the Gutmann-Beckett test and competency in the hydroborative reduction of six organic substrates, as well as computationally, by fluoride ion affinity and hydride ion affinity methods. The effects of tuning the aliphatic linker length, substituents at the boron, and changing the cluster from a seven-atom phosphorus system to a seven-atom arsenic system on reactivity are studied.

Indium Triflate's Transformative Role in Modern Organic Synthesis: A Five‐Year Survey of Functionalization, Cyclization, and Multicomponent Reactions

AbstractIndium triflate (In(OTf)3) has proven to be a powerful and sustainable catalyst in the synthesis of modern organic compounds, enabling a variety of transformations such as functionalization, cyclization, and multicomponent reactions. To provide insight into the most recent methods and applications, this study attempts to provide a comprehensive and up‐to‐date summary of these advances in the application of indium triflate as a catalyst in organic synthesis, focusing on the last five years of literature. The application of indium triflate as opposed to alternative indium(III) catalysts in organic transformations will be the main emphasis of this review, which will cover recent developments through research articles and reviews published between 2019 and 2023. This minireview will make a significant contribution to the existing literature by consolidating recent advancements in the use of indium triflate in modern organic synthesis.

Ultrahigh-Performance Fiber-Supported Iron-Based Ionic Liquid for Synthesizing 3,4-Dihydropyrimidin-2-(1H)-ones in a Cleaner Manner.

Herein, a fiber-supported iron-based ionic liquid as a type of fibrous catalyst has been developed for the synthesis of bioactive 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) via three-component Biginelli reactions in a cleaner manner. The described fibrous catalyst was obtained from the commercially available polyetheretherketone (PEEK) fiber by postfunctionalization processes and was characterized and analyzed in detail by means of diversified technologies. Furthermore, the fiber-supported iron-based ionic liquids could mediate the classical three-component Biginelli reactions to proceed smoothly to gain a variety of substituted DHPMs with yields of up to 99%. The superior catalytic activities of the fibrous catalyst were ascribed to the quasi-homogeneous medium by ionic liquids generated in the surface layer of the PEEK fiber, which could afford an appropriate reaction zone and could further be available for the aggregation of substrates to facilitate the three-component reaction. Notably, the fibrous catalyst is available for recycling over 10 runs just by a pair of tweezers, and the operational procedure was capable of enlarging the catalytic system to the gram-scale without any performance degradation, which provided a cleaner manner to take advantage of the iron-based catalyst in organic synthesis with potential industrialization prospects.

Noncovalent interaction with a spirobipyridine ligand enables efficient iridium-catalyzed C–H activation

Exploitation of noncovalent interactions for recognition of an organic substrate has received much attention for the design of metal catalysts in organic synthesis. The CH–π interaction is especially of interest for molecular recognition because both the C–H bonds and the π electrons are fundamental properties of organic molecules. However, because of their weak nature, these interactions have been less utilized for the control of organic reactions. We show here that the CH–π interaction can be used to kinetically accelerate catalytic C–H activation of arenes by directly recognizing the π-electrons of the arene substrates with a spirobipyridine ligand. Computation and a ligand kinetic isotope effect study provide evidence for the CH–π interaction between the ligand backbone and the arene substrate. The rational exploitation of weak noncovalent interactions between the ligand and the substrate will open new avenues for ligand design in catalysis.

Laser Synthesis of Catalytically Active Materials for Organic Synthesis and Sensor Technology

Introduction: The catalytic activity of metallic nanomaterials depends on their surface morphology. A widely known method is the laser synthesis of metal nanostructures by depositing on dielectric surfaces from aqueous solutions containing metal complexes. The article analyzes the factors that favor the production of conductive, catalytic, and sensory-active deposits by laser method. It is shown that the two main factors is the presence of a large number of charged defects on heterophase surfaces and the structure of metal-containing complexes in solution. This is typical for mono- and bimetallic alloys, the components of which interact with the laser beams according to the autocatalytic type. Using the example of laser deposition from solutions of Co, Ni, Fe, Zn, and Ag salts with homo- and heterophase dielectrics, the sensory and catalytic properties of the deposits are compared by impedance spectroscopy and voltammetry. It has been shown that heterophase precipitation significantly enhances the catalysis response. Background: It is known that the highest catalytic activity exhibits nanostructured and highly porous materials with a large specific surface area and materials containing surface heterogeneity in the form of charged acid-base centers. Such materials are necessary for the creation of new catalysts for organic synthesis and for the creation of new sensor materials for enzyme-free microbiosensors. Active development of new methods for the synthesis of such materials is underway. But not all of them give the expected result. Methods: Laser synthesis methods have the best prospects, including the method of laser-induced metal deposition. This is the laser synthesis of metal nanostructures by depositing dielectric surfaces from aqueous solutions containing metal complexes. Results: Аrticle analyzes the factors that favor the production of conductive, catalytic, and sensory-active deposits by laser method. It is shown that the two main factors are the presence of a large number of charged defects on heterophase surfaces and the structure of a metal-contained complex in solution. This is typical for mono- and bimetallic alloys, the components of which interact with the laser beam according to the autocatalytic type. Using the example of laser deposition from solutions of Co, Ni, Fe, Zn, and Ag salts with homo- and heterophase dielectrics, the sensory and catalytic properties of the deposits are compared by impedance spectroscopy and voltammetry. Conclusion: It has been shown that heterophase precipitation significantly enhances the catalysis response. It is shown that the laser deposition reaction has an autocatalytic mechanism in a dynamic mode. The results of autocatalysis can be used in a stationary mode to create a microbiosensor for glucose, as well as to create a technology for laser refining rare metals and hydrogen energy in a dynamic mode.

Carbene‐Catalyzed Asymmetric Ring‐Opening Reaction of Biaryl Lactams to Access Axially Chiral Biaryls†

Comprehensive SummaryAxially chiral biaryls represent the most important class of atropisomers, and they widely exist in natural products and biologically active molecules. They also constitute a unique scaffold for chiral ligands and catalysts in organic synthesis. The development of synthetic methods to obtain such chiral compounds has received widespread attention, among which catalytically atroposelective ring‐opening of configurationally labile compounds represents one of the most attractive strategies. Various substrates with strained cyclic structures, such as the renowned Bringmann's lactones, can undergo asymmetric transformation into stable atropisomers. Known advancement primarily relies on metal catalyst combined with well‐designed chiral ligands, the approaches utilizing organocatalysis as a critical resolution strategy are notably scarce. In this study, we disclosed a N‐heterocyclic carbene (NHC)‐catalyzed asymmetric ring‐opening reaction of biaryl lactams via direct atroposelective nucleophilic activation. The optimized bulky carbene catalyst ensures that the reaction can proceed under mild conditions, affording the desired product with good to excellent yields and atroposelectivity.

Biocatalysis for Green Synthesis: Exploring the Use of Enzymes and Microorganisms as Catalysts for Organic Synthesis, Highlighting Their Advantages over Traditional Chemical Catalysts in Terms of Selectivity, Efficiency, and Environmental Impact

This study explores the use of microorganisms and enzymes as catalysts for organic synthesis, highlighting the advantages of these catalysts over conventional chemical catalysts in terms of selectivity, efficiency, and environmental effect. This study explains the major advantages of biocatalysis, such as its high selectivity, mild reaction conditions, efficiency, low environmental impact, and compatibility with renewable feedstocks, by looking at several case studies and experimental results. The importance of biocatalysis in advancing environmentally friendly and sustainable manufacturing processes is emphasized.

Ammonium tetrafluoroborate: Novel Unprecedented Catalyst for the Synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones through Biginelli Reaction

AbstractA novel method has been developed to use ammonium tetrafluoroborate (NH4BF4) directly as catalyst in Biginelli reaction. A new paradigm of the Biginelli reaction for the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones derivatives found the use of ammonium tetrafluoroborate as a novel, inexpensive, readily available, non‐toxic and mild catalyst in good to excellent yields. Notably, this is the first time that ammonium tetrafluoroborate is directly used as a catalyst in organic synthesis. So far, no organic reaction is available in literature where NH4BF4 is directly used as catalyst. However, some reactions are found where NH4BF4 is used with other catalysts as promoters or additives. The protocol developed has several advantages, such as highly efficient, simple, atom‐economical, environmentally friendly, easy synthetic and purification methods.

Synthesis of Fluorine-Containing Multisubstituted Oxa-Spiro[4,5]cyclohexadienones via a Fluorinated Alcohol-Catalyzed One-Pot Sequential Cascade Strategy.

In recent years, the application of fluorinated alcohols as solvents, cosolvents, or additives has become important in modern organic synthesis. However, their potential as efficient catalysts in organic synthesis has not been well-explored. In this article, we report on the development of a one-pot sequential cascade reaction of p-quinone methides with difluoroenoxysilanes using hexafluoroisopropanol as catalyst. This reaction allows for the preparation of fluorinated multisubstituted oxa-spiro[4,5]cyclohexadienones. By using 50 mol % 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP), the reaction proceeds smoothly to yield 1,6-conjugated products, which are then subjected to oxidative dearomatization/hemiacetalization using PhI(OAc)2. The overall process affords moderate to high yields and excellent diastereoselectivities.

Catalytic Intermolecular Deoxygenative Coupling of Carbonyl Compounds with Alkynes by a Cp*Mo(II)-Catalyst.

Carbonyl is highly accessible and acts as an essential functional group in chemical synthesis. However, the direct catalytic deoxygenative functionalization of carbonyl compounds via a putative metal carbene intermediate is a formidable challenge due to the requirement of a high activation energy for the cleavage of strong C═O double bonds. Here, we report a class of bench stable and readily available Cp*Mo(II)-complexes as efficient deoxygenation catalysts that could catalyze the direct intermolecular deoxygenative coupling of carbonyl compounds with alkynes. Enabled by this powerful Cp*Mo(II)-catalyst, various valuable heteroarenes (10 different classes) were obtained in generally good yields and remarkable chemo- and regioselectivities. Mechanistic studies suggested that this reaction might proceed via a sequence of C═O double bonds cleavage, carbene-alkyne metathesis, cyclization, and aromatization processes. This strategy not only provided a general catalytic platform for the rapid preparation of heteroarenes but also opened a new window for the applications of Cp*Mo(II)-catalysts in organic synthesis.

Colloidal and Nanosized Catalysts in Organic Synthesis: XXVII.1 Hydrogenation of Carbonyl Compounds in the Presence of Supported Nickel Catalysts

Colloidal and Nanosized Catalysts in Organic Synthesis: XXVII.1 Hydrogenation of Carbonyl Compounds in the Presence of Supported Nickel Catalysts

Synthesis of N-heterocyclic carbene (NHC)-Au/Ag/Cu benzotriazolyl complexes and their catalytic activity in propargylamide cycloisomerization and carbonyl hydrosilylation reactions.

Carbene-metal-amide (CMA) complexes of gold, silver, and copper have been studied extensively for their photochemical/photocatalytic properties and as potential (pre-)catalysts in organic synthesis. Herein, the design, synthesis, and characterization of five bench-stable Au-, Ag-, and Cu-NHC complexes bearing the benzotriazolyl anion as an amide donor, are reported. All complexes are synthesized in a facile and straightforward manner, using mild conditions. The catalytic activity of the Ag and Cu complexes was studied in propargylamide cycloisomerization and carbonyl hydrosilylation reactions. Both CMA-catalyzed transformations proceed under mild conditions and are highly efficient for a range of propargylamides and carbonyl compounds, respectively, affording the desired corresponding products in good to excellent yields.

Application and Mechanism Study of Carbon-Based Metal-Free Catalysts in Organic Synthesis

Application and Mechanism Study of Carbon-Based Metal-Free Catalysts in Organic Synthesis