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Comprehensive Summary: The concurrent implementation of cascade reactions that combine biocatalysis and chemocatalysis is a challenging undertaking. Electrocatalysis provides versatile catalytic abilities and allows for mild reaction conditions, offering the potential for designing concurrent chemoenzymatic cascade reactions. The research on bioelectrocatalysis has primarily concentrated on utilizing electrocatalysis to achieve cofactor regeneration of enzymes. In contrast with previous reports, herein, we developed a deracemization strategy involving the concurrent combination of biocatalytic reduction and anodic oxidation in an undivided cell to achieve chiral sulfoxides, demonstrating the good compatibility. We anticipate this study will offer an alternative pathway for the design of the cascade reaction combined with electrocatalysis and biocatalysis. [ABSTRACT FROM AUTHOR]

Ti‐13Nb‐13Zr (TNZ), a representative of β‐type titanium alloys, has garnered significant interest in biomedical implant materials recently because of its high strength, and closer elastic modulus to human bone. However, TNZ alloy does not have antibacterial properties and has the potential to cause implant‐related infection, even implantation failure. Herein, TNZ alloy is alloyed by Cu element and the surface is modified by anodic oxidation (AO) to enhance the biocompatibility and antimicrobial qualities. The corrosion resistance, antimicrobial properties, and cytotoxicity of the TNZ‐3Cu alloy before and after anodization are studied by X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy, electrochemical test, mechanical property test, and cell test. The experimental results show that the primary constituents of the TNZ‐3Cu alloy are α″ martensite and β phase after solid solution treatment. The elastic modulus of TNZ‐3Cu alloy is (65 ± 1.33) GPa, 9 GPa lower than that of TNZ alloy. The AO treatment significantly improves the hydrophilicity and antibacterial properties as well as the corrosion resistance by the formation of a dense oxides composites coating. The cell test results show that the coating improves the initial adhesion of cells by the high hydrophilic surface and promotes the proliferation of cells by the release of copper ions. [ABSTRACT FROM AUTHOR]

The high oxidation potential of Au(I)/Au(III) redox couple renders the development of gold‐catalyzed cross‐coupling reactions highly challenging. In the pursuit of Au(I)/Au(III) redox catalysis, various strategies, such as the use of stoichiometric oxidants, merged gold/photoredox systems, or ligand‐enabled approaches, have been adopted to achieve the oxidation of Au(I) to Au(III) complexes. Recently, electrochemical anodic oxidation‐based gold redox catalysis has emerged as a new technique to facilitate gold‐catalyzed cross‐coupling reactions. This concept article provides a succinct overview of electrochemical gold redox catalysis, highlighting the challenges and potential future developments. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ammonia removal from wastewater by electrooxidation (EO) is an interesting approach because of its efficiency and easy maintenance and operation. In this process, ammonia is oxidized to nitrate or nitrogen gas. Ammonia conversion to the latter is desirable to remove nitrogen from the liquid; however, the influence of several operating parameters on nitrate generation has not been systematically evaluated. Therefore, this work aimed to investigate the effect of current density (200–800 A m−2), chloride concentration (0–10 000 mg L) and initial pH (5–9) on the electrooxidation of an ammonia‐containing solution and the associated generation of nitrate. For this purpose, a laboratory‐scale electrochemical reactor containing two Ti/RuO2 electrodes was used. RESULTS: The results indicated high ammonia removal efficiency – 98% within 150 min at 800 A m−2 and 97% within 240 min at 500 A m−2 – generating around 70 and 102 mg NO3−‐N L−1 under these conditions, respectively. Increasing the chloride concentration from 5000 to 7500 mg L−1 reduces the electrolysis time needed to remove all ammonia from 180 to 150 min. However, with increasing initial chloride concentration, the amount of nitrate generated rose from 69.5 to 135.9 mg N L−1. On the other hand, in the test without chloride, nitrate generation was considerably lower (0–0.61 mg L−1). CONCLUSION: The higher the current density applied, the greater the ammonia removal by EO. Although current density influenced the ammonia oxidation rates, it did not directly affect nitrate formation. The lower the concentration of ammonia in the solution, the more significant was the fraction of nitrate generated. Most of the inlet ammonia was oxidized to nitrogen gas, nitrite was rapidly oxidized to nitrate and higher chloride concentrations enhanced ammonia oxidation. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

This Minireview examines a selection of case studies that showcase distinctive and enabling electrochemical approaches that have allowed for the generation and reaction of carbocation intermediates under mild conditions. Particular emphasis is placed on the progress that has been made in this area of organic synthesis and polymer chemistry over the past decade. [ABSTRACT FROM AUTHOR]

The advancement in electrochemical techniques has unlocked a new path for achieving unprecedented oxidations and reductions of aryl radical precursors in a controlled and selective manner. This approach facilitates the construction of aromatic carbon−carbon and carbon−heteroatom bonds. In light of the green merits and the growing importance of this technique in aryl radical chemistry, this review aims to provide an overview of the recent advance in the electrochemical generation of aryl radicals organized by the aryl radical precursor type, with a focus on the substrate scope, limitation, and underlying mechanism, thereby inspiring future work on electrochemical aryl radical generation. [ABSTRACT FROM AUTHOR]

We report an electrochemically promoted decarboxylation of readily available carboxylic acid and subsequent Mumm rearrangement to synthesize the corresponding imides. The reaction features external oxidant‐free, transition metal‐free mild conditions, and good functional group tolerance, affording various imides in moderate to good yields. Mechanistic studies reveal that the selective oxidation of aliphatic carboxylic acids appears to be the key step in this transformation. [ABSTRACT FROM AUTHOR]

The current comprehensive review covers four main parts, of which some are presented in the form of a personal account. 1. Anodic oxidation of a) N‐alkyl and N,N‐diallyl carbonyl moieties, b) Azacycloalkyl amides and the effect of ring‐size on the outcome, c) Lactams, d) Sulfonamides, and e) The effect of a substituent R attached to carbonyl (N−CO−R) or sulfonamides (N−SO2R) on their oxidation potentials. 2. Anodic oxidation of aromatic amides, in particular of type Ph2CHCONHAr, lacking hydrogen(s) at the α‐position to nitrogen. They undergo three types of bond‐cleavage, yielding a variety of fragmentation products. 3. a) Anodic oxidation of symmetrical bisamides of type ZCONH(CH2)nNHCOZ (Z=Me, Ph, Ar; n=2–4) under constant current electrolysis, in methanol. For n=3, 4 they afford mostly mono‐ and dimethoxylation products. For n=2 they undergo ′CH2−CH2′ bond cleavage to yield fragmentation products. b) Anodic oxidation of symmetrical bisamides of type ArCONH(CH2)2NHCOAr under controlled potential electrolysis, in acetonitrile, leads to gem‐unsymmetrical bisamides of type ArCONHCH2NHCOMe as the major product, in fair yields. 4. Utilization of the anodic process in organic synthesis to form C−C bonds by both intra‐ and inetrmolecular processes; as well as C−O and C−N bonds for generating heterocycles. [ABSTRACT FROM AUTHOR]

In this study, a superhydrophobic surface was successfully prepared on Al alloy 5052 using a simple anodic oxidation method followed by fluorination treatment. This study demonstrates the construction of rough structure of Al oxide by an anodic oxidation reaction, which improves the superhydrophobicity of the alloy. The top, tilt, and cross‐views of the samples were characterized by field‐emission scanning electron microscopy and focused ion beam. The chemical composition of the samples was analyzed by energy‐dispersive X‐ray spectroscopy and Fourier‐transform infrared spectroscopy. The structure of the surface was effectively modified as the anodization time increased. The optimum anodic oxidation reaction was carried out for 4 min in a 0.2‐M H3PO4 aqueous electrolyte at 50°C under a constant voltage of 120 V to create a pore‐and‐dendrite hybrid nanostructure. The water contact angle values were maximized in the hybrid nanostructure because their solid fraction area was smaller than that in the porous structure. Corrosion measurements proved that the superhydrophobic surface can significantly inhibit the corrosion of the substrate alloy with an inhibition efficiency of 99.99%. In addition, the prepared superhydrophobic sample exhibited good self‐cleaning properties. [ABSTRACT FROM AUTHOR]

Diamond films with different grain sizes are deposited on TiO2 nanotube (TNT) arrays prepared by anodic oxidation using a microwave plasma chemical vapor deposition reactor. The scanning electron microscope, X‐Ray diffractometer, and Raman results indicate that the diamond film is successfully deposited and that the substrate undergoes a phase transition due to the diamond deposition temperature, resulting in the rutile phase becoming dominant with lower energy bandgap and work function. Notably, after 5 h of deposition, a relatively continuous microcrystalline film is formed on the TNTs, and the diamond grains change from spherical to pyramidal and show excellent electron field emission behavior, with a low turn‐on field of 0.5 V μm−1 and a current density of 85.9 μA cm−2. In addition, the deposition environment of the nanocrystalline diamond has a large impact on the substrate morphology, resulting in a blocked electron transport path, which reduces the overall field emission performance. The enhanced performance is attributed to the synergistic effect between the highly efficient 1D electron path of the TNTs, the negative electron affinity of the diamond surface, and the lower work function of rutile TiO2. [ABSTRACT FROM AUTHOR]

Photocatalysis has attracted attention as a method for purifying pollutants, but how to simply and efficiently prepare catalyst films with high surface areas is still a challenge. Herein, a chrysanthemum‐like CuO–TiO2–Ag photocatalyst is prepared by anodic oxidation and magnetron sputtering. Scanning electron microscopy and energy dispersive spectrometry analyses show that Ag nanoparticles are uniformly modified on the surface of chrysanthemum‐like CuO–TiO2. Moreover, the influences of the thickness of the TiO2 film and the content of Ag nanoparticles on the degradation of rhodamine B (RhB) are studied by controlling the sputtering time. Among the prepared nanocomposites, the chrysanthemum‐like CuO–TiO2‐2.5‐Ag‐2 proves to have the maximal degradation level with regard to RhB by removing 91.16% RhB after 120 min under UV light. This is because the large surface area offers more active sites. In addition, the trapping experiments show that when CuO–TiO2 is decorated by Ag nanoparticles, this contributes to the movement of a number of photogenerated electrons from the conduction band of TiO2 to Ag, thereby improving the efficiency of charge transfer. The findings reveal that the photodegradation efficiency of the prepared nanocomposites in this study is greatly related to the thickness of the TiO2 film and the content of Ag nanoparticles. [ABSTRACT FROM AUTHOR]

An electrochemical methodology for the construction of α‐CF3‐substituted carbonyl compounds in moderate to good yields under exogenous metal and oxidant‐free conditions has been developed. The protocol involves the single‐electron oxidation of the aryl ring to generate a radical cation followed by a three‐electron SN2 reaction resulting in the formation of α‐CF3 substituted ketones. [ABSTRACT FROM AUTHOR]

In high‐frequency printed circuit boards (PCBs), there is an inherent contradiction between minimizing signal loss and maximizing adhesion strength. To tackle this issue, this work presents a simple approach by developing an enhanced interlayer through a two‐step process involving anodization/APTES (3‐aminopropyltriethoxysilane) treatment. The anodization yields micro/nano oxide structures with low surface roughness, thereby reducing the skin effect. One side of the enhanced interlayer is mechanically anchored and chemically bonded to copper foils, while the other side is coupled with bismaleimide/triazine‐based resins (BT resins), significantly augmenting the adhesion strength. Eight‐layer PCBs manufactured employing this method exhibit an insertion loss of −1.3553 dB in−1 at 32 GHz. Compared to two conventional brown oxide methods, the insertion loss is reduced by 7.80% and 3.24%, respectively, with a more substantial reduction observed at higher frequencies. The peel strength of samples ranges from 0.554 to 0.589 N mm−1, demonstrating maximum enhancements of 34.78% and 164.13% in comparison to the two brown oxide methods, respectively. Moreover, eight‐layer PCBs undergo lead‐free reflow soldering tests, solder float tests, and thermal fatigue tests without encountering any failures. Consequently, the proposed method holds significant practical significance in addressing the challenge associated with low signal loss and high adhesion strength in high‐frequency PCBs. [ABSTRACT FROM AUTHOR]

Based on the existing literature, active chlorine‐mediated electrochemical oxidation has been extensively studied when Cl‒ is added or Cl‒ is already present in the water matrices, as well as when Cl‒ is released from the target organic pollutants during their degradation. However, no attempts have been published concerning the fate and role of bromide (Br‒) ions released during the anodic oxidation (AO) of organobromine compounds. Therefore, the AO of bromophenol blue dye (BPB) was investigated in a parallel plate flow reactor using a boron‐doped diamond (BDD) anode. The effect of the applied current on the color removal efficiency and mineralization of BPB solution was examined and compared with AO of phenol red (PR) which has a similar molecular structure to BPB (but without Br) in order to understand the role of Br heteroatoms on the mineralization of BPB. Faster and higher mineralization and discoloration were achieved when treated with BPB solution compared to PR under similar experimental conditions. This behavior was associated with the electrogeneration of BrO‒, from the heteroatom Br which is released as the bromide ion (Br‒), during the degradation of BPB. The active bromine species are formed via direct and indirect oxidation approaches which were proposed based on ion chromatography and linear scanning voltammetry analysis. [ABSTRACT FROM AUTHOR]

Isoxazol(in)es are widely featured structural motifs in natural products, agrochemicals, and pharmaceuticals. The first intermolecular approach for a direct electrochemical synthesis from readily available aldoximes is reported. Isoxazoles and isoxazolines were obtained in yields up to 81 %. The synthesis is carried out in an undivided cell as the simplest electrochemical set‐up and requires only the use of electric current as traceless oxidizing agent. The application of inexpensive and widely available electrode materials in combination with recyclable supporting electrolytes and solvents paves the path for translation of the presented reaction onto preparative scale. This is underlined by successful scale‐up to multi‐gram runs. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of sulfaguanidine was investigated in PBS buffer aqueous solutions. Cyclic voltammograms have shown that (1) the Sg provided a well‐defined irreversible oxidation peak (2) the signal‐to‐background current ratio is 3 times higher at COOH‐MWCNT coated GCE than that of bare GCE and (3) the modifying GCE surface by COOH‐MWCNT led to a significant improvement (2.7 folds) of the electrochemical response. It has been shown that Sg oxidizes according to a diffusion‐controlled mechanism. A linear calibration curve was obtained for the oxidation of Sg at 10–70 μM. The COOH‐MWCNT coated GCE has also been successfully used for the determination of Sg in real samples. [ABSTRACT FROM AUTHOR]

Hydrogenation reactions are staple transformations commonly used across scientific fields to synthesise pharmaceuticals, natural products, and various functional materials. However, the vast majority of these reactions require the use of a toxic and costly catalyst leading to unpractical, hazardous and often functionally limited conditions. Herein, we report a new, general, practical, efficient, mild and high‐yielding hydrogen‐free electrochemical method for the reduction of alkene, alkyne, nitro and azido groups. Finally, this method has been applied to deuterium labelling. [ABSTRACT FROM AUTHOR]

The tetracycline group (TCs) includes the most common antibiotics for treatment of both human and animal infections. TCs are resistant to biological degradation; hence, conventional wastewater treatments are unable to remove these contaminants. Here, the utilization of different electrochemical processes, such as electro‐Fenton (EF), direct anodic oxidation (AO) and indirect oxidation by electrogenerated active chlorine (EAC), for the treatment of aqueous solutions of oxytetracycline (OTC), which is one of the TCs, was studied. The effect of various operating conditions was evaluated to optimize the selected processes. EAC gave the fastest abatement of OTC, but the lowest removal of TOC and formation of chlorate. However, the utilization of carbon felt cathodes allowed the formation of chlorate to be reduced. AO gave the highest TOC removals, but it required the use of an expensive anode, as BDD, and high cell potentials. EF performed with pressurized‐air (5–10 bar) presented intermediate removals of OTC and TOC with respect to AO and EAC and consumed the least energy. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

With LABS, an open source Python‐based lab software is established that enables users to orchestrate automated synthesis setups. The software consists of a user‐friendly interface for data input and system monitoring. A flexible backend architecture enables the integration of multiple lab devices. The software allows users to easily modify experimental parameters or routines and switch between different lab devices. Compared to previously published projects, we aim to provide a more widely applicable and easily customizable automation software for any experimental setup. The usefulness of this tool was demonstrated in the oxidative coupling of 2,4‐dimethyl‐phenol to the corresponding 2,2'‐biphenol. In this context, the suitable electrolysis parameters for flow electrolysis were optimized by way of design of experiments. [ABSTRACT FROM AUTHOR]

Herein, we reported the electrochemical hydroboration of olefins to access the organoboron derivatives in a one‐pot reaction under air and at room temperature. This reaction manifold was applied to a broad range of alkenes with 40–90% yields and good functional group tolerance without using a metal catalyst or an additional hydride source. Mechanistic studies suggested that this anodic oxidation conducted in an undivided cell allowing the production of a boron radical species, which initiates the hydroboration of olefins event by a radical addition process. [ABSTRACT FROM AUTHOR]

Special porous anodic aluminum oxide (AAO) membranes are created on Al in a phosphonic acid electrolyte solution through one‐step anodic oxidation and modified with polydimethysiloxane using a vapor deposition technique. In this context, the anodic oxidation time is tuned during its process. As such, the Al surface's wettability, and self‐cleaning property are controlled by the tunable anodic oxidation time, for the anodic oxidation, time can regulate the structure of the AAO and the proportion of the air‐liquid interface. [ABSTRACT FROM AUTHOR]

The use of microfluidic electrochemical reactors has been introduced several decades ago, but their application in the field of wastewater treatment is more recent (2010). The parallel development of electrochemical advanced oxidation processes (EAOPs) as promising technologies for effluent treatment make them good candidates to be implemented as thin film cells. This allows favoring the mass transfer, which is particularly interesting for heterogenous electro‐oxidation. Moreover, the energy requirement is reduced, while there is possibility to treat low‐conductivity solutions. This review intends to provide instructions on the main operating parameters to be optimized during the EAOPs treatment. Directions on engineering aspects have been given to overcome the main drawbacks of microreactors, such as fouling, scaling, and low treatment capacity, based on recent encouraging results given in literature. The promising development of hybrid processes that combine electroseparation with electroconversion would also benefit from such reactor designs. [ABSTRACT FROM AUTHOR]

In this study, ZnO nanostructures with different morphologies were produced by varying anodizing parameters (time and voltage), and the photocatalytic activities of these structures were examined. ZnO nanostructures were fabricated through different voltage and duration consisting of nine samples with KHCO3 solution as an electrolyte. The produced ZnO nanostructures were investigated by using X‐ray diffraction (XRD), scanning electron microscopy, X‐ray photoelectron spectroscopy, and UV–vis spectrophotometer. It was found that the morphology of ZnO was formed as nanosponge, nanoflower, nanowire, heterogeneous structures. ZnO nanostructures were identified by matching XRD peaks due to the ICDD database. Experiments on photocatalytic degradation of methylene blue demonstrated the photocatalytic activity of ZnO samples. The best photocatalytic performance of the samples was observed by S1 sample, which was anodized for 30 min in 0.05 M of KHCO3 electrolyte at 20 V, after 420 min exposure of the UV–vis light source with the degradation rate of 87.3%. Such ZnO nanostructures exhibit unique properties and have high potential for wastewater treatment. [ABSTRACT FROM AUTHOR]

Hydrogen generated in electrolyzers is discussed as a key element in future energy scenarios, but oxygen evolution as the standard anode reaction is a complex multi‐step reaction requiring a high overpotential. At the same time,it does not add value‐the oxygen is typically released into the atmosphere. Alternative anode reactions which can proceed at similar current densities as the hydrogen evolution are, therefore, of highest interest. We have discovered a high‐performance electrode based on earth‐abundant elements synthesized in the presence of H2O2, which is able to sustain current densities of close to 1 A cm−2 for the oxidation of many organic molecules, which are partly needed at high production volumes. Such anode reactions could generate additional revenue streams, which help to solve one of the most important problems in the transition to renewable energy systems, i.e. the cost of hydrogen electrolysis. [ABSTRACT FROM AUTHOR]

Herein, we report a practical method for de novo preparation of imino‐d‐ribitol and C‐azanucleosides. The diastereopure Imino‐d‐ribitol was synthesized on a multigram scale by simple manipulation, and late‐stage anomeric derivatization by regio‐ and diastereoselective electrochemical C(sp3)−H activation enabled the efficient synthesis of the corresponding C‐azanucleosides with high β‐selectivity. [ABSTRACT FROM AUTHOR]

Isocyanides are well‐known as efficient CO surrogates and C1 synthons in modern organic synthesis. Although tremendous efforts have been devoted to fully exploiting the reactivity of isocyanides, these transformations are primarily limited by their utilization of stoichiometric toxic chemical oxidants. With the recent resurgence of organic electrochemistry, which has considerably laid dormant over the past several decades, electrolysis has been identified as a green and powerful tool to enrich structural diversity by solely utilizing electric current as clean and inherently safe redox equivalents of stoichiometric chemical oxidants. In this regard, the unique reactivity of isocyanides has been studied in numerous electrochemical transformations. This review comprehensively highlights the most relevant progress in electrochemical strategies towards the functionalization of isocyanides up until June of 2022, with a focus on reaction outcomes and mechanisms. [ABSTRACT FROM AUTHOR]

A facile and environmentally friendly electrochemical protocol is herein reported for the C(sp2)−C(sp3) cross dehydrogenative coupling between imidazopyridines and N,N‐dimethylanilines. The broad functional group compatibility includes halogens, ester, alcohol, sulfone as well as thiophene. This methodology is also suitable for benzo[d]imidazo[2,1‐b]thiazole, thiazoimidazole and tetrahydroisoquinoline, and can be scaled up to 5 mmol. Mechanistic insights are discussed. [ABSTRACT FROM AUTHOR]

Herein, we report an electrochemical oxidative palladium‐catalyzed carbonylation‐carbocyclization of enallenols to afford γ‐lactones and spirolactones, which proceeds with excellent chemoselectivity. Interestingly, electrocatalysis was found to have an accelerating effect on the rate of the tandem process, leading to a more efficient reaction than that under chemical redox conditions. [ABSTRACT FROM AUTHOR]

This contribution presents an electrochemical method for the synthesis of nano‐ and micrometer‐sized TiO2 layers on titanium sheets suitable for chemistry classes. By varying the synthesis parameters, multi‐colored compact layers as well as nanoporous structures can be obtained. These porous layers are photocatalytically active and, furthermore, can be used as an anode material in sodium‐ion batteries for which corresponding experiments are presented. Additionally, appropriate models to explain both the color impression by interference and the growth mechanism of compact and porous TiO2 layers by ion migration are shown. Finally, opportunities to connect the presented models and experiments to chemistry and science classes are discussed. [ABSTRACT FROM AUTHOR]

A method is proposed that encompasses visible light/anodic oxidation‐derived persulfates as well as the formation of a novel polyferric flocculation agent, which can synergistically treat oilfield wastewater. In this method, under irradiation of visible light, the anodic oxidation online generated sulfate is partly converted into sulfate radicals for oxidation of organic pollutants. It partly oxidizes divalent iron ions added at the end of electrolysis into polyferric species that can flocculate and degrade organic pollutants in the wastewater. The advantages of this process are environmental safety and overall low cost. Under optimal conditions (pH = 7.0, electrolysis time of 50 min, applied current intensity of 1.2 A, [Na2SO4] = 0.8 mol/L), the system exposed to simulated sunlight achieved 73.3% TOC removal, showing high efficiency in degrading organic pollutants. The experiment proved that the Na2SO4 in the electrolyte can be partially recovered. [ABSTRACT FROM AUTHOR]

In the present work, an easy and scalable method to prepare lithium titanium oxide nanotubes with stable and reversible lithium storage properties is reported. This material could be an excellent candidate for lithium recovery from aqueous solutions or have a direct application as Li‐ion batteries electrodes in a circular economy perspective. Vertically oriented anatase nanotubes are grown by anodic oxidation in an ethylene glycol‐based electrolyte. Then, the nanotubes are hydrothermally converted into a mixed lithium titanate. Morphological and crystallographic characterizations confirm the successful shape‐preserving conversion after which the nanotubes are subjected to electrochemical cycling. XRD and XPS analyses confirm a significant lithium uptake after cycling, and its recovery is investigated by means of an acidic treatment. While allowing for an almost complete recovery of the lithium integrated in their structure, the nanotubes also showed excellent morphological and structural stability proving to be excellent candidates for lithium recovery purposes. [ABSTRACT FROM AUTHOR]

Furanose ring oxygen‐substituted artificial nucleosides show unique pharmacological activities even without incorporation into oligonucleotides, and are used as anticancer and antiviral agents. Practical synthetic routes to such nucleosides are of exceptional importance to enhance the development of (oligo)nucleotide therapeutics. Herein, we demonstrate that direct anodic N‐α hydroxylation is possible in aqueous media to realize the practical synthesis of these versatile intermediates for azanucleoside derivatives. [ABSTRACT FROM AUTHOR]

In the last years, an increasing attention has been devoted to the utilization of anodic oxidation (AO) technologies for the treatment of wastewater polluted by recalcitrant organics. Recently, Ti4O7 was proposed as a promising anode for AO for the treatment of various organics. Here the potential utilization of commercial Ti4O7 anodes has been evaluated considering the electrochemical treatment of synthetic wastewater contaminated by three very different organic molecules (namely, oxalic acid, phenol and Acid Orange 7), all characterized by a very high resistance to AO. The performances of Ti4O7 were compared with that of two largely investigated anodes: Boron‐doped diamond (BDD), which is probably the most effective electrode for AO, and an Ir‐based anode which presents a relatively low cost. Moreover, the effect of various operative conditions (current density, mixing rate and initial concentration of the organic) was evaluated by both experimental studies and the adoption of a theoretical model previously developed for BDD anodes. It was shown that the performances of the process can be improved by a proper selection of operative conditions. Moreover, it was found that the proposed model can be effectively used to predict the effect of operative parameters at Ti4O7 anodes, thus helping the process optimization. [ABSTRACT FROM AUTHOR]

Herein, porous titanium materials with honeycomb pore structure are prepared by freeze casting. The effect of freezing temperature on the pore structure and mechanical properties is also investigated. As the freezing temperature decreases from −10 to −50 °C, the compressive strength decreases from 79.5 ± 9.2 to 55.0 ± 4.3 MPa, and then increases to 90.1 ± 4.4 MPa. Porous titanium with an average pore size of 111.3 ± 25.2 μm and porosity over 60% are obtained at −10 °C. And the porous titanium is observed to form a neatly arranged nanopore structure with an average pore size of 28.5 ± 2.8 nm on the surface after anodizing. These nanopore structures can promote MG‐63 cell adhesion and proliferation, thus improving the biocompatibility of porous titanium. Further, in the simulated body fluid culture experiment, culturing for 3 days can induce Ca2+ and PO43− to nucleate and deposit on the surface of anodized porous titanium, while 7 days can deposit a lot of apatite on the surface. In contrast, no apatite deposition is observed on the surface of the porous titanium sample without anodizing. These prepared porous titanium materials with high porosity, large pore size, sufficient mechanical properties, good biocompatibility, and biological activity might be a potential biomedical material. [ABSTRACT FROM AUTHOR]

A general and efficient intramolecular halo‐amination of unactivated alkenes for the synthesis of various halogenated N‐heterocycles was developed via electrochemical anodic oxidation. This protocol proceeds in a simple undivided cell by employing LiI or LiBr as redox mediums and halogen sources. A wide range of halogenated N‐heterocycles, including three‐, five‐, and six‐membered N‐heterocycles were constructed in moderate to good yields at room temperature. Notably, this electrochemical oxidative transformation avoids the utilization of external oxidants and strong bases, therefore represents an environmentally benign approach. [ABSTRACT FROM AUTHOR]

This personal account provides an overview of work conducted in my research group, and through collaborations with other chemists and engineers, to develop flow electrolysis cells and apply these cells in organic electrosynthesis. First, a brief summary of my training and background in organic synthesis is provided, leading in to the start of flow electrosynthesis in my lab in collaboration with Derek Pletcher. Our work on the development of extended path electrolysis flow reactors is described from a synthetic organic chemist's perspective, including laboratory scale‐up to give several moles of an anodic methoxylation product in one day. The importance of cell design is emphasised with regards to achieving good performance in laboratory electrosynthesis with productivities from hundreds of mg h−1 to many g h−1, at high conversion in a selective fashion. A simple design of recycle flow cell that can be readily constructed in a small University workshop is also discussed, including simple modifications to improve cell performance. Some examples of flow electrosyntheses are provided, including Shono‐type oxidation, anodic cleavage of protecting groups, Hofer‐Moest reaction of cubane carboxylic acids, oxidative esterification and amidation of aldehydes, and reduction of aryl halides. [ABSTRACT FROM AUTHOR]

The morphinans are an important class of structurally fascinating and physiologically important natural products as exemplified by the famous opium alkaloids of the morphine family. Although this class of secondary metabolites from the juice of the opium poppy capsule was already used for medicinal purposes thousands of years ago, chemical modifications are still being applied to the core structure today in order to achieve the most specific effect on the various receptor subtypes possible with the fewest possible side effects. The unusual architecture of the morphinan core has also proven to be a highly challenging target for total synthesis. This review highlights electrosynthetic approaches towards natural and semisynthetic morphinan alkaloids. The historical progress in applying anodic aryl‐aryl couplings to the construction of the morphinan framework is described in chronological order while particular benefits and challenges concerning the electrochemical transformations are grouped together, including the influence of substitution patterns, protecting groups, and reaction conditions. [ABSTRACT FROM AUTHOR]

Natural products have played a significant role not only in discovery of drugs but also in development of organic chemistry by providing the synthetic challenges. Inspired by biosynthesis where enzymes catalyze a multi‐step reaction, we have investigated the natural product synthesis utilizing electrochemical reactions as the key step. Electrochemical organic synthesis, so‐called electro‐organic synthesis, enables to control the reactivity of substrates simply by tuning electrolysis conditions. In this Personal Account, we overview the recent progress of our research projects about natural product synthesis, in which anodic oxidation of phenol compounds affords the important frameworks such as diaryl ether, spirodienone, and spiroisoxazoline. [ABSTRACT FROM AUTHOR]

This Personal Account describes the author's groups' research in the field of electrosynthetic anodic oxidation, beginning with initial trial and error attempts with the Shono oxidation. Early setbacks with complex rotameric amide mixtures, provided the ideal environment for the discovery of the Oxa‐Shono reaction‐Osp2‐Csp3 bond cleavage of esters‐providing two useful products in one‐step: aldehyde selective oxidation level products and a mild de‐esterification method to afford carboxylic acids in the process. The development of the Oxa‐Shono reaction provided the impetus for the discovery of other electrically propelled‐Nsp2‐Csp2 and Nsp2‐Csp3‐bond breaking reactions in bioactive amide and sulfonamide systems. Understanding the voltammetric behaviour of the molecule under study, switching between controlled current‐ or controlled potential‐ electrolysis, and restricting electron flow (the reagent), affords exquisite control over the reaction outcomes in batch and flow. Importantly, this bio‐inspired advance in electrosynthetic dealkylation chemistry mimics the metabolic outcomes observed in nature. [ABSTRACT FROM AUTHOR]

Nickel oxides/hydroxides are active electrocatalysts for the hydrogen evolution reaction (HER) in alkaline water electrolysis. A durable activity of Ni with Ni(OH)2 was observed mainly on porous substrates, such as nickel foam or carbon cloth. Herein, we examined the effect of anodic oxidation on the HER using smooth samples of Ni, Ni with graphene, and Ni with C introduced by a low‐temperature plasma treatment. Electrochemical measurements in 1.0 M KOH showed that a strong activation toward HER was achieved by voltammetric cycling to potentials of the formation of Ni3O4, Ni2O3, and/or NiO2. The presence of C enhanced this activation. The effect of C was explained by the accumulation of larger amounts of these products as a result of a deteriorated passivity, their higher compactness (demonstrated by higher impedance), and the longer durability under conditions of HER (revealed by a slower cathodic reduction). The durability of oxides in porous C structures can be explained by anodic potentials in pores owing to the ohmic potential drop. It is proposed that anodic oxidation might be used for the reactivation of Ni cathodes for water electrolysis. [ABSTRACT FROM AUTHOR]

BACKGROUND: The presence of micro‐pollutants in conventional wastewater treatment plants raises environmental concerns due to their insufficient removal. Non‐biological methods are needed to treat such compounds and this work demonstrates the use of electrochemical oxidation for the degradation of the drug dexamethasone (DEX). RESULTS: A cell consisting of a boron‐doped diamond anode and a stainless steel or carbon cloth cathode was employed, with Na2SO4 being the electrolyte. DEX degradation rate, at the low level of mg L−1 (0.25–2 mg L−1), increases with increasing current (0.02–0.2 A m−2), as well as in the presence of sodium persulfate (50–250 mg L−1); the latter is electrochemically activated to produce additional oxidants and enhances degradation in a synergistic way. A rate constant of 0.194 min−1 was recorded for 0.5 mg L−1 DEX degradation at 0.2 A m−2 with 150 mg L−1 persulfate. The water matrix had little effect on performance compared to experiments in pure water; the only exception was the presence of chloride (50–250 mg L−1), which substantially improved rates due to the formation of active chlorine species (up to about five times). Carbon cloth accelerated DEX removal by up to three times compared to stainless steel and this was partly due to its adsorptive capacity; similarly, reactions involving DEX transformation products (TPs) also occurred faster. Seven TPs were identified and profiles were followed; reaction pathways involve hydroxylation, oxidation, decarboxylation and ring‐opening reactions, followed by fluorine release in the liquid phase. CONCLUSION: A hybrid technology based on electrochemical oxidation and persulfate activation is proposed for the treatment of residual pharmaceuticals in environmental matrices. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Surface protection has drawn increasing attention in lithium (Li) metal batteries by simultaneously taking advantage of the uniform potential distribution and high conductivity, whereas tuning the composition of the protective film and improving the resistance at the interface of protective film/Li metal remain the challenges. Herein, a solid‐state anodic oxidation strategy for preparing an in situ protective film for enhanced cycle life of Li metal anode is illustrated. The solid‐state anodic oxidation of lithium metal is realized for the first time, and the method can be further modified for tuning the composition of the protective film for highly ionic conductive fluorine‐rich interface. Surface electrodeposition simulations indicate the important role of the conductive protective film in increasing the uniform potential distribution on the Li surface. The as‐prepared in situ fluorinated protective film efficiently suppresses the dendrite growth and promotes the cycling performance of the Li metal full cell in commercial ester electrolyte without any additive. This work opens up a new avenue for fabricating unique in situ protective films with controlled composition on Li surface for energy storage applications. [ABSTRACT FROM AUTHOR]

Electrosynthesis of unsaturated esters from furan derivatives, reported by Torii et al. in 1976, is an attractive method for the valorization of furanoic platform chemicals. Nevertheless, it has received practically no attention, presumably due to specific reaction conditions including the use of expensive Pt electrodes. With the aim of expanding the application of Torii‐type ester electrosynthesis, we explored the electrochemical transformation of O‐furfuryl ethylene glycols and N‐furfuryl amino alcohols to esters 5. These can be obtained in two consecutive electrochemical steps: bis‐alkoxylation of the furan derived substrates 3 to give spirocycles 4, followed by ring‐opening involving oxidative fragmentation of the C−C bond. Both steps can be carried out at ambient conditions, using inexpensive graphite electrodes; however, each step required a different supporting electrolyte and acidic additive to achieve good yields of the product. Additionally, conditions were found for efficient one‐pot transformation of N‐furfuryl amino alcohols to esters 5 while O‐furfuryl ethylene glycols under the same conditions gave esters 5 in moderate yields. [ABSTRACT FROM AUTHOR]

Oxidative functionalization of alkenes is a versatile strategy for the preparation of many oxygen-containing scaffolds, such as epoxides, diols, or carbonylcontaining compounds. In addition to conventional chemical methods, which rely on the utilization of stoichiometric amounts of oxidizing reagents, some electrochemical procedures have been developed to achieve these transformations. Typical electrochemical procedures employ tailored and often complex redox mediators to achieve the target transformation. Herein we present a modular approach for the synthesis of epoxides, diols, and aldehydes from a single set of reaction components. With sodium bromide as an inexpensive electrocatalyst and water as the oxygen donor, the outcome of the reaction (epoxide, 1,2-diol, or aldehyde) can be selected by simply tuning the electrolysis conditions. This convenient platform has been accomplished by developing a selective one-pot three-step bromide-electrocatalyzed epoxidation/ring opening/carboncarbon cleavage sequence. Its modularity permits the selection of the desired product, as the sequential reaction can be ended when the target compound has been formed. Themethod has been applied to a diversely functionalized terminal and non-terminal olefins. [ABSTRACT FROM AUTHOR]

In sharp contrast to hypervalent iodine(III) compounds, the isoelectronic bromine(III) counterparts have been little studied to date. This knowledge gap is mainly attributed to the difficult‐to‐control reactivity of λ3‐bromanes as well as to their challenging preparation from the highly toxic and corrosive BrF3 precursor. In this context, we present a straightforward and scalable approach to chelation‐stabilized λ3‐bromanes by anodic oxidation of parent aryl bromides possessing two coordinating hexafluoro‐2‐hydroxypropanyl substituents. A series of para‐substituted λ3‐bromanes with remarkably high redox potentials spanning a range from 1.86 V to 2.60 V vs. Ag/AgNO3 was synthesized by the electrochemical method. We demonstrate that the intrinsic reactivity of the bench‐stable bromine(III) species can be unlocked by addition of a Lewis or a Brønsted acid. The synthetic utility of the λ3‐bromane activation is exemplified by oxidative C−C, C−N, and C−O bond forming reactions. [ABSTRACT FROM AUTHOR]

Herein we reported the electrochemical hydroboration of alkynes by using B2Pin2 as the boron source. This unprecedented reaction manifold was applied to a broad range of alkynes, giving the hydroboration products in good to excellent yields without the need of a metal catalyst or a hydride source. This transformation relied on the possible electrochemical oxidation of an in situ formed borate. This anodic oxidation performed in an undivided cell allowed the formation of a putative boryl radical, which reacted on the alkyne. [ABSTRACT FROM AUTHOR]

The activation and functionalization of C−H bonds using palladium catalysts has become an important part of a modern chemist toolbox, as it enables a range of highly useful transformations to be achieved in a single synthetic step. However, many established protocols for such C−H functionalizations rely on stoichiometric amounts of chemical oxidants, which are often expensive and/or toxic, and lower the atom efficiency. Striving for more sustainable transformations, electrochemistry has re‐emerged as an alternative atomless approach towards oxidation, potentially offering cheap and more user‐friendly methodologies. Herein we discuss recent endeavors to combined electrochemistry and Pd‐catalyzed C−H activation/functionalization, to achieve C−C, C−X, C−O and C−P bond formation. [ABSTRACT FROM AUTHOR]

The electrochemical activation of stannylmethyl ethers was exploited for Friedel–Crafts alkylation of arenes at near‐neutral conditions. Single cell anodic oxidation of stannylmethyl ethers leads to oxonium ions which fragment to carbenium ions in the presence of electron rich arenes. Low oxidation potential of stannylmethyl ethers and buffered conditions enable the Friedel–Crafts reaction with a wide range of arenes including the substrates with acid‐sensitive groups. [ABSTRACT FROM AUTHOR]

A flow electrolysis cell that enables operation at high temperatures and pressures has been designed and developed. The cell, with a cylindrical shape and concentric electrodes, can be easily assembled using commercially available fluidic components. The compact design of the device permits easy temperature control using a commercial column heater. Temperatures ranging from −10 °C to +150 °C and pressures up to 70 bar have been successfully applied for long operation periods. The cell performance has been evaluated using the anodic methoxylation of N‐formylpiperidine as a model. Very high conversions and selectivities have been achieved with single‐pass processing, and high productivities of 73 mmol/h with electrolyte recycling. The high pressure and temperature capabilities of the cell have been used to demonstrate the negative effect that re‐dissolved hydrogen gas can have on hydrogen‐releasing electrochemical reactions in undivided cells, owing to undesired anodic oxidation of hydrogen. [ABSTRACT FROM AUTHOR]