Oxidation Reaction Research Articles

Thermodynamic Studies on the Pathway and Mechanism of Coal-Oxygen-Water Coupling Reaction of Low-Temperature Oxidation

ABSTRACT It is imperative to have an in-depth understanding of the pathway and mechanism of coal-oxygen-water coupling reaction during low-temperature oxidation of coal, not only for preventing fires in the coal industry but also for reducing emissions of hazardous gases. In this study, in-situ Infrared spectroscopy characterization and quantum chemical calculations were combined to investigate in detail the chemical interactions between coal, moisture, and oxygen. In-situ infrared oxidation experiments ascertained the types and amounts of hydroxyl, aliphatic hydrocarbon, and carbonyl functional groups in lignite coal samples with varied moisture content during LTO. Subsequently, three typical molecular structures of functional groups mainly involved in the coal-oxygen reaction were chosen as the research representatives, and their reactivity was analyzed using density functional theory (DFT). Thus, the main reaction pathways of these functional groups during the LTO of coal were studied using quantum chemical methods. The results indicated that the moisture in coal significantly affected the coal–oxygen reaction by altering the chemisorption processes in the coal–oxygen combination and the active sites in coal molecules. Quantitative calculation of thermodynamic parameters such as the enthalpy and activation energy showed that moisture had a promoting effect on some reaction steps while hindering others. Moreover, the mechanism of coal-oxygen-water coupling reaction was also explored based on the reaction sequence of intermediate complexes.

Unlocking the Catalytic Potential of Anionic Micelles: Insights into the Ce(IV)-Directed Phenylalanine Oxidation Kinetics in Asymmetric Hydrophobic Environments.

The oxidation kinetics of phenylalanine (Phe) by Ce(IV) have been examined in both the absence and presence of aqueous micellar media with asymmetric tails, specifically using sodium dodecyl sulfate (SDS) and sodium tetradecyl sulfate (STS) surfactants. The reaction progress was monitored by observing a decrease in absorbance using UV-vis spectroscopy. Interestingly, the kinetic profile revealed a consistent increase in the observed rate constant values as the concentration of the surfactant increased. The kinetic results have been analyzed by using numerous experimental studies, such as dynamic light scattering (DLS), zeta potential, 1H NMR analysis, FT-IR spectroscopy, conductometry, scanning electron microscopy (SEM), fluorometry, time-correlated single-photon counting (TCSPC), and transmission electron microscopy (TEM). Micellar aggregates maintain their spherical shape in the presence of the substrate, even at higher surfactant concentrations, as revealed by microstructural analysis. The substrate molecules are encapsulated to a greater extent in the inner micellar core of STS micelles on account of the more hydrophobic nature of STS surfactants. Therefore, in STS micellar media, fewer substrate molecules diffuse to the Stern layer compared to the SDS micellar medium, resulting in fewer molecules participating in the oxidative transformation reaction. As a result, the rate enhancement of oxidation kinetics is less pronounced in STS micelles than in SDS micelles. A plausible mechanism that aligns with the kinetic results has been highlighted, along with the interpretation of the Piszkiewicz model, to explain the observed catalytic effect of both micellar mediums.

10-Fold Increase in Hydrogen Atom Transfer Reactivity for a Series of S = 1 FeIV═O Complexes Over the S = 2 [(TQA)FeIV═O]2+ Complex via Entropic Lowering of Reaction Barriers by Secondary Sphere Cycloalkyl Substitution.

Nonheme iron enzymes utilize S = 2 iron(IV)-oxo intermediates as oxidants in biological oxygenations. In contrast, corresponding synthetic nonheme FeIV═O complexes characterized to date favor the S = 1 ground state that generally shows much poorer oxidative reactivity than their S = 2 counterparts. However, one intriguing exception found by Nam a decade ago is the S = 1 [FeIV(O)(Me3NTB)]2+ complex (Me3NTB = [tris((N-methyl-benzimidazol-2-yl)methyl)amine], 1O) with a hydrogen atom transfer (HAT) reactivity that is 70% that of the S = 2 [FeIV(O)(TQA)]2+ complex (TQA = tris(2-quinolylmethyl)amine, 3O). In our efforts to further explore this direction, we have unexpectedly uncovered a family of new S = 1 complexes with HAT reaction rates beyond the currently reported limits in the tripodal ligand family, surpassing oxidation rates found for the S = 2 [FeIV(O)(TQA)]2+ complex by as much as an order of magnitude. This is achieved simply by replacing the secondary sphere methyl groups of the Me3NTB ligand with larger cycloalkyl-CH2 (R groups in 2OR) moieties ranging from c-propylmethyl to c-hexylmethyl. These 2OR complexes show Mössbauer data at 4 K and 1H NMR spectra at 193 and 233 K that reveal S = 1 ground states, in line with DFT calculations. Nevertheless, they give rise to the most reactive synthetic nonheme oxoiron(IV) complexes found to date within the tripodal ligand family. Our DFT study indicates transition state stabilization through entropy effects, similar to enzymatic catalysis.

Unravelling the Effect of Oxygen on the Sintering Mechanism of Pt/CeO2 in the CO Oxidation Reaction.

Sintering significantly contributes to the deactivation of supported metal catalysts under reaction conditions, influenced by various factors, including temperature, atmosphere, and metal-support interactions. The sintering mechanism under the reaction conditions remains complex and ambiguous. This study delves into the sintering behavior of platinum on CeO2 under CO oxidation conditions, mainly employing transmission electron microscopy to elucidate the effects of different gas components on the sintering mechanism at elevated temperatures. An atmosphere rich in oxygen promotes the sintering of Pt via the Ostwald ripening mechanism, characterized by the growth of larger nanoparticles at the expense of smaller ones. Conversely, sintering proceeds through particle migration and coalescence in the absence of oxygen, leading to the aggregation of nanoparticles. The obtained Pt/CeO2 catalysts exhibit enhanced catalytic performance after treatment with argon and stoichiometric reaction gases, contrasting with the deactivation observed under oxygen-rich conditions, which is attributed to varied Pt valence states. These findings provide insights into understanding the sintering mechanisms and inform the design of heterogeneous catalysts.

Effect of Strain on the Photocatalytic Reaction of Graphitic Carbon Nitride: Insight from Single-Molecule Localization Microscopy.

Strain engineering in two-dimensional nanomaterials holds significant potential for modulating the lattice and band structure, particularly through localized strain, which enables modulation at specific regions. Despite the remarkable effects of local strain, the relationships among local strain, spatial correlation of photogenerated charge carriers, and photocatalytic performance remain elusive. The current study coupled single-molecule localization microscopy with coordinate-based colocalization (CBC) analysis to explain these relationships. The methodology involved mapping the spatial distributions of photoinduced oxidation and reduction reaction sites across graphitic carbon nitride (g-C3N4) nanosheets, quantifying and spatially resolving their spatial correlation, and also evaluating their photocatalytic activity. The study examined 65 individual g-C3N4 nanosheets, revealing interparticle and intraparticle heterogeneity, which was classified based on their CBC score distributions. Among the 65 g-C3N4 nanosheets, type A nanosheets predominated (45 out of 65) and demonstrated both correlated and noncorrelated subregions along some wrinkles. In contrast, type B nanosheets (20 out of 65) were primarily characterized by noncorrelated subregions with minimal correlated localizations. The coexistence of both noncorrelated and correlated subregions inferred the structure of the wrinkles as folding wrinkles, which have larger tensile-strained areas than rippling wrinkles. Folding wrinkles promote colocalization through the formation of type I band alignment at tensile-strained subregions. This band alignment also enhances photocatalytic activity through a funneling effect and improved light absorption, leading to higher specific activity in correlated subregions compared to noncorrelated ones. The role of strain-induced band alignment in modulating the spatial correlation of the photoredox reaction and the photocatalytic performance at the subregion level is highlighted.

Superhydrophilicity and Electronic Modulation on Self-Supported Lignin-Derived Carbon Coupled with NiO@MoNi4 for Enhancing Urea Electrolysis.

Developing highly efficient biomass-derived carbon-based electrocatalysts remains challenging for urea electrolysis because most of these electrocatalysts show powder morphology, which can lead to Ostwald ripening during the reaction process, and its reaction mechanism should be further verified. Herein, self-supported lignin-derived carbon coupling NiO@MoNi4 heterojunction (NiO@MoNi4/C) possesses superhydrophilic properties and electronic modulation, boosting the performance of urea electrolysis. Electrochemical results show that an indirect oxidation step for urea oxidation reaction (UOR) and Volmer-Heyrovsky mechanism for hydrogen evolution reaction (HER) occurs on the surface of NiO@MoNi4/C. It displays low potentials for UOR (E10/500/1000 = 1.28/1.41/1.47 V) and for HER (E-10/-500/-1000 = -38/-264/-355 mV) in 1.0 MKOH + 0.5M urea electrolyte solution. The good activity is ascribed to the self-supported lignin-derived carbon and heterojunction, which increases the number of active sites, optimizes electronic structure, and improves electron transfer. Benefiting from the self-supported lignin-derived carbon, NiO@MoNi4/C demonstrates corrosion resistance and superhydrophilicity, which avoids Ostwald ripening and accelerates gas-liquid transfer, thus, maintaining for 100 h at ±1000/±1500 mA cm-2 during the UOR and HER test. This work provides a good catalyst for urea electrolysis and presents a promising way for preparing lignin-derived carbon-based catalysts while expanding the application of lignin-based biomass carbon materials.

Advances in Phosphorus-Based Catalysts for Urea Electrooxidation: A Pathway to Sustainable Waste to Energy Conversion Through Electrocatalysis

The electrocatalytic oxidation of urea has gained significant attention as a promising pathway for sustainable energy conversion and wastewater treatment that could address the dual goals of waste remediation and renewable energy generation. Phosphorous function groups-based catalysts have been introduced as potential electrode materials for enhancing the urea electrocatalytic oxidation reaction (UEOR) due to their unique structural properties, high stability, and tunable electronic characteristics. This review presents recent advancements in phosphorous-based catalysts (phosphates/phosphides) for UEOR. It highlights the development of novel phosphorous materials, synthesis approaches, and electrocatalytic insights into urea electrooxidation on phosphorous-based materials surfaces. Key topics include the role of different metal phosphates, surface modifications, and compositional optimizations to improve electrocatalytic efficiency and durability. Through a critical evaluation of current research trends and technological progress, this review underscores the potential of phosphate-based catalysts as environmentally friendly and efficient alternatives for sustainable waste-to-energy conversion via UEOR. The review concludes with a perspective on future directions for optimizing phosphate catalysts, scaling up practical applications, and integrating UEOR systems into renewable energy infrastructures.

Evaluation of the Potential of Alternative Brazilian Woods to Replace Oak in Wine Production

Objective: The general objective of this study was to carry out a systematic review on the influence of wood from Brazilian flora on wine production, as alternatives to French and American oak. Theoretical Framework: In the current scenario, French and American oak barrels are the most requested in the world. But the high cost of these containers on the international market has encouraged producers to look for cheaper alternatives. Method: In the methodology, an integrative literature review was adopted, in which an analysis was carried out based on studies present on digital platforms. Results and Discussion: All woods showed a tendency to increase volatile acidity, notably jequitibá. This increase was caused by ethanol oxidation reactions, which mainly form acetaldehyde and acetic acid. For Jatobá, Ipê, Amburana and Balsam wood, whose increase in volatile acidity was lower than in oak and jequitibá, the data may indicate a lower permeability, which consequently allows for less micro-oxygenation of the drink. Research Implications: We conclude from this work, based on a general analysis by all the authors studied here, that wood is an important resource in wine production. Coming from the northern hemisphere, oak is the noblest material used in the maturation of the drink, as in addition to providing chemical compounds, it can promote moderate micro-oxygenation of the wine, but there are possibilities of using wood from Brazilian flora instead. Originality/Value: The size of wood pores is a crucial factor in its applicability. There are woods in the Brazilian flora with potential for use in oenology, notably amburana and pink jequitibá, while others, such as Jatobá and Jequitibá, require more in-depth analysis of their suitability.

Cucurbituril‐Manipulated Supramolecular Electrodes for Highly Active and Stable (Photo)electrocatalytic Oxidation Reactions

AbstractThe robust immobilization and activity regulation of molecular catalysts on solid electrodes have remained persistent challenges in catalysis. Herein, cucurbituril (CB[7]) acts is first demonstrated as a bifunctional medium to firmly immobilize molecular catalyst CoTMPyP onto various metal oxide electrodes, including TiO2, BiVO4, α‐Fe2O3, and WO3, through host‐guest and electrostatic interactions. This approach not only secures stable attachment of the catalyst but also optimizes its electronic structure and catalytic activity. The CB[7]‐mediated supramolecular electrodes exhibit exceptional performance in electrocatalytic oxygen evolution reaction (OER), ethanol oxidation reaction, hydrazine oxidation reaction, and photoelectrocatalytic water oxidation. For instance, TiO2‐CB[7]‐CoTMPyP electrode achieves a turnover frequency (TOF) of 5.30 s−1 at an overpotential of 600 mV for OER, and BiVO4‐CB[7]‐CoTMPyP photoanode delivers a water oxidation photocurrent density of 6.00 mA cm−2 at 1.23 V versus RHE under simulated solar irradiation. Mechanistic studies reveal CB[7] plays a critical role beyond merely serving as a linker: it enhances charge accumulation around the cobalt sites, promotes reactants adsorption at these sites, reduces reaction energy barrier, and accelerates charge transfer rate, thereby significantly boosting catalytic activity. This work provides a groundbreaking pathway for the design and fabrication of cost‐effective, high‐performance molecular‐based electrodes for (photo)electrocatalytic reactions.

Recent Strategies of Oxygen Carrier Design in Chemical Looping Processes for Inherent CO2 Capture and Utilization

AbstractChemical looping processes are considered a promising pathway for the efficient production of various fuels and chemicals. Temporally or spatially separated reduction and oxidation reaction in chemical looping can offer various advantages such as enhancing energy efficiency, surpassing equilibrium limitations, and eliminating the need for separation. However, the efficiency of the chemical looping process highly depends on the performance of the oxygen carrier. Higher gas conversion can increase separation efficiency and higher solid conversion can reduce the amount of cycled oxygen carrier. The performance indicators are highly related to the thermodynamic properties of the oxygen carriers and their redox kinetics. This review introduces some key articles and recent achievements for the enhancement of such properties. The different research strategies are discussed for enhancing the performance of stoichiometric and non-stoichiometric oxygen carriers. Through the rational design of oxygen carrier material, an energy-efficient chemical looping process is possible.

In Situ Metal Vacancy Filling in Stable Pd-Sn Intermetallic Catalyst for Enhanced CC Bond Cleavage in Ethanol Oxidation.

A common challenge in electrochemical processes is developing high performance, stable catalysts for specific chemical reactions. In this work, a Pd-Sn intermetallic compound with Pd site deficiency (Pd1.9-xSn) (x = 0.06) and trace amount of SnOx was synthesised by controlled process. Under the electrochemical conditions, the deficient Pd site is filled by metallic Sn, which generates a highly active and stable (Pd1.84Sn0.06)Sn catalyst for ethanol oxidation reaction (EOR). The crystal structure and atomic arrangements for synthesized and in situ generated compound are comprehensively characterized by various spectroscopic techniques. The in situ generated catalyst exhibits excellent performance toward EOR (anodic reaction in fuel cell), which outperforms the state-of-the-art Pd/C catalyst by three times in terms of activity. Furthermore, it is observed that the catalyst preferentially cleaves the CC bond in ethanol, which is a crucial process that enhances the efficiency of the fuel cells. The catalyst retains its superlative activity even after 1500 cycles of continuous operation. The mechanism for EOR and CC bond cleavage is evidenced by operando Infra Red spectroscopyand Differential Electrochemical Mass Spectroscopy (DEMS), and the driving force toward excellent performance has been proposed via theoreticalcalculations.

Optimizing s‐p Orbital Overlap between Sodium Polysulfides and Single‐Atom Indium Catalyst for Efficient Sulfur Redox Reaction

P‐block metal carbon‐supported single‐atom catalysts (C‐SACs) have emerged as a promising candidate for high‐performance room‐temperature sodium‐sulfur (RT Na‐S) batteries, due to their high atom utilization and unique electronic structure. However, the ambiguous electronic‐level understanding of Na‐dominant s‐p hybridization between sodium polysulfides (NaPSs) and p‐block C‐SACs limits the precise control of coordination environment tuning and electro‐catalytic activity manipulation. Here, s‐p orbital overlap degree (OOD) between the s orbitals of Na in NaPSs and the p orbitals of p‐block C‐SACs is proposed as a descriptor for sulfur reduction reaction (SRR) and sulfur oxidation reaction (SOR). Compared to NG and NG‐supported InN4 (NG‐InN4) SACs, the nitrogen‐doped graphene‐supported InN5 (NG‐InN5) SACs show the largest s‐p OOD, demonstrating the weakest shuttle effect and the lowest reaction energy barriers in both SRR and SOR. Accordingly, the designed catalysts allow the Na‐S pouch batteries to retain a high capacity of 490.7 mAh g‐1 at 2 A g‐1 with a Coulombic efficiency of 96% at a low electrolyte/sulfur (E/S) ratio of 4.5 μl. This work offers an s‐p orbital overlap descriptor describing the interaction between NaPSs and p‐orbital‐dominated catalysts for high‐performance RT Na‐S batteries.

Dual Wavelength LEDs Induce Reactive Oxygen Species and Nitric Oxide That Inhibit the Production of Dihydrotestosterone by 5-α Reductase.

Androgenetic alopecia (AGA) causes balding in approximately 50% of adults. One primary cause of AGA is synthesis of dihydrotestosterone from testosterone by 5-α reductase. Systemic pharmaceutical interventions have potentially serious side effects, necessitating development of localized interventions. One such approach is administration of red light via low level light therapy (LLLT), which has promising clinical data. However, the LLLT mechanism of action remains unclear. We investigated the ability of LLLT to stimulate nitric oxide (NO) and the role of NO in inhibition of DHT synthesis. Our results show that red and red-orange light induce NO release in a cell-free platform. In A549 and HEK293T cells, we demonstrate 620 and 660 nm LED-emitted light stimulates the production of NO, reactive oxygen species (ROS), and decreases DHT synthesis. These results provide a plausible mechanism of action for LLLT employing LED-emitted red and red-orange wavelengths of light to treat AGA.

Artificial Photosynthetic Assemblies Constructed by NH2-UiO-66 Decorated with Spatially Separated Dual Cocatalysts for Enhanced Photocatalytic Uranium Reduction.

The phenomenon of rapid migration of photogenerated charges in natural photosynthetic systems has motivated the design of efficient photocatalysts capable of fast charge separation and efficient reaction kinetics for photocatalytically assisted enrichment and separation of uranium U(VI) in uranium wastewater. In this study, we developed a biomimetic photocatalytic system MnOx/NH2-UiO-66-rGO (M/UiO-rGO) with spatially separated dual cocatalysts. Among them, rGO functions to capture electrons and participates in reduction reactions, while MnOx captures holes and participates in oxidation reactions. The M/UiO-rGO catalyst exhibits excellent performance in photocatalytic reduction of uranium (reaching 91.8% in 1 h), and even under natural light conditions, it exhibits excellent uranium removal ability (80.4%). Using multispectral coupling technology, we further confirmed that enriched uranium undergoes a continuous and complex reaction process of "capture-reduction-free radical oxidation-nucleation-crystallization". This work presents a viable strategy for designing biomimetic photocatalysts with efficient charge separation and rapid reaction kinetics for environmental purification purposes.

Tumor Microenvironment-Responsive Nanoparticles Enhance IDO1 Blockade Immunotherapy by Remodeling Metabolic Immunosuppression.

The clinical efficacy of immune checkpoint blockade (ICB) therapy is significantly compromised in the metabolically disordered tumor microenvironment (TME), posing a formidable challenge that cannot be ignored in current antitumor strategies. In this study, TME-responsive nanoparticles (HMP1G NPs) loaded with 1-methyltryptophan (1-MT; an indoleamine 2,3-dioxygenase 1 [IDO1] inhibitor,) and S-nitrosoglutathione (GSNO; a nitric oxide donor) is developed to enhance the therapeutic efficacy of 1-MT-mediated ICB. The HMP1G NPs responded to H+ and glutathione in the TME, releasing Mn2+, GSNO, and 1-MT. The released Mn2+ catalyzed the production of abundant reactive oxygen species and nitric oxide from hydrogen peroxide and GSNO, and the generated nitric oxide, synergistically with 1-MT, inhibited the accumulation of kynurenine mediated by IDO1 in the tumor. Mechanistically, HMP1G NPs downregulated tumor cell-derived IDO1 via the aryl hydrocarbon receptor/signal transducer and activator of transcription 3/interleukin signaling axis to improve kynurenine/tryptophan metabolism and immunosuppression. In a murine breast cancer model, treatment with HMP1G NPs elicited effective antitumor immunity and enhanced survival outcomes. This study highlights a novel nano-platform that simultaneously improves metabolism and enhances ICB efficacy to achieve a new and efficient antitumor strategy.

Advanced Solid Amine Adsorbents with Exceptional Oxidative Stability for Efficient Capture of Low-concentration CO2.

Solid amine adsorbents designed for capturing trace amounts of carbon dioxide (CO2) offer a promising approach. However, developing solid amine adsorbents that concurrently exhibit high oxidative stability and superior CO2 adsorption capacity remains a significant challenge. Here, ED-PEI/PEG@FS-TBP, an innovative and highly stable CO2 adsorbent is introduced. This material involves the functionalization of polyethyleneimine (PEI) with 1,2-epoxydodecane (ED), effectively transforming primary amines into secondary amines, thereby mitigating urea formation. Furthermore, the chelator embedded within the fumed silica (FS) supports sequestering metallic impurities that would otherwise catalyze oxidation reactions. The integration of polyethylene glycol (PEG) forms hydrogen bonds with PEI, effectively barricading oxygen access and safeguarding against PEI oxidation. ED-PEI/PEG@FS-TBP achieves an outstanding CO2 adsorption capacity of 1.49mmolg-1 at 298 K and 0.0004bar. Notably, after 20 days of oxidative aging in an environment with 75% relative humidity and 383 K, ED-PEI/PEG@FS-TBP exhibits remarkable oxidative stability, with a deactivation rate constant (kdeact) 93% lower than that of PEI@FS. Its excellent oxidative stability, cycling stability, and high thermal stability, underscore its unparalleled potential for the capture of low-concentration CO2.

Decoding the Catalytic Potential of Dinuclear 1st-Row Transition Metal Complexes for Proton Reduction and Water Oxidation.

The growing interest in renewable energy sources has led to a significant focus on artificial photosynthesis as a means of converting solar energy into lucrative and energy-dense carbonaceous fuels. First-row transition metals have thus been brought to light in the search for efficient and high-performance homogenous molecule catalysts that can accelerate energy transformation and reduce overpotentials during the catalytic process. Their dinuclear complexes have opportunities to enhance the efficiency and stability of these molecular catalysts, primarily for the hydrogen evolution reaction (HER) and water oxidation reaction (WOR). Recently, our group improved the catalytic activity, efficiencies, and stability of dinuclear molecular catalysts, particularly toward HER. Although one dinuclear complex has been tested for WOR, it demonstrated activity as water oxidation precatalysts. First-row transition metals are a great option for sustainable catalysis because they are readily available, reasonably priced, and have multifaceted coordination chemistry. Examples of these metals are cobalt, copper, and manganese. The structure-catalytic performance relationships of this first-row transition metal-based dinuclear catalysts are noteworthily interpreted in this account, providing avenues for optimizing their performance and advancing the development of sustainable and effective energy conversion technologies.

Cucurbit[8]uril-stabilized charge transfer: An efficient supramolecular approach toward a heterogeneous organic photocatalyst for aerobic oxidation reactions.

Host-stabilized charge transfer (HSCT) has been widely utilized in macrocycle-derived supramolecular assemblies and architectures. However, there has been less research attention focused on the direct fabrication of pure organic photocatalysts using HSCT. Herein, four viologen derivatives (m-PV2+, m-BPV2+, d-PV2+, and d-BPV2+) with different electron donor-acceptor (D-A) structures were synthesized. Their host-guest complexes with cucurbit[8]uril (Q[8]) in an aqueous solution could be switched using the substituted electron donor moieties, in which the host-guest complexes of m-BPV2+@Q[8] andd-BPV2+@Q[8] exhibited HSCT interactions. Control experiments revealed that the d-BPV2+@Q[8] complex had the strongest ability to sensitize singlet oxygen (1O2). This was ascribed to the increased π-conjugation of d-BPV2+@Q[8], which led to more effective HSCT upon encapsulation by the Q[8] host. Consequently, the d-BPV2+@Q[8] complex could be easily employed as a heterogeneous photocatalyst for the photooxidation reaction of thioether com-pounds with high selectivity. In particular, d-BPV2+@Q[8] was successfully applied to the synthesis of sulfoxide drugs, such as the con-version of inexpensive Iberverin ($7.0 per gram) to the expensive bioactive inhibitor Iberin ($19500.0 per gram) in high yield (94%).

Divergent Oxidation Reactions of E- and Z-Allylic Primary Alcohols by an Unspecific Peroxygenase.

Unspecific Peroxygenases (UPOs) catalyze the selective oxygenation of organic substrates using only hydrogen peroxide as the external oxidant. The PaDa-I variant of the UPO from Agrocybe aegerita catalyses the oxidation of Z- and E-allylic alcohols with complementary selectivity, giving epoxide and carboxylic acid/aldehyde products respectively. Both reactions can be performed on preparative scale with isolated yields up to 80%, and the epoxidations proceed with excellent enantioselectivity (>99% ee). The divergent reactions can also be used to transform E/Z mixtures of allylic alcohols, enabling both product series to be isolated from a single reaction. The utility of the epoxidation method is exemplified in the total synthesis of both enantiomers of the insect pheromone disparlure, including a highly enantioselective gram-scale transformation. These reactions provide further evidence for the potential of UPOs as catalysts for the scalable preparation of important oxygenated intermediates.

SYNTHESIS AND RESEARCH OF THE CATALYTIC SYSTEM xAlPO4 . yCu3(PO4)2

Individual orthophosphate catalysts AlPO4 and Cu3(PO4)2 were synthesized. A new synthesis technique was developed and a new complex aluminum-copper (II) orthophosphate catalytic system of the type xAlPO4·yCu3(PO4)2 was obtained based on them (К-1–К-7), which has the predicted physical and chemical properties. The content of both orthophosphates in the catalyst structure varies in the range of 0.5 - 99.5 wt. %. At the final heat treatment temperature (700oC), all synthesized complex catalysts K-1–K-7 are X-ray crystalline. The process of thermal treatment of catalysts contributes to their gradual dehydration and release of water from the structure of the samples, as well as the occurrence of characteristic endothermic effects at the appropriate temperatures. At high temperatures of heat treatment (about 500 oC), the processes of crystallization of the structures are observed on the synthesized samples K-1–K-7. Heating of all samples of a complex catalytic orthophosphate system of the type xAlPO4.yCu3(PO4)2 at temperatures above 700 oC leads to their complete dehydration and the formation of anhydrous salts. It can be predicted that the synthesized new complex oxide catalytic heterogeneous systems of the type xAlPO4.yCu3(PO4)2 have been will show improved both acidic surface properties and catalytic parameters: activity and selectivity in reactions of partial oxidation of n-alkanes to valuable products.