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Plasmonic coupling among nanocavities creates a significant collective response of near-field enhancement, leading to numerous applications such as extraordinary optical transmittance, enhanced spectroscopy, energy harvesting, photo-enhanced catalysis, meta-lens, etc. We report here a perturbation theory based on the two-body interaction potential to clarify the plasmonic coupling between/among nanocavities. With this theory, we demonstrated that one can calculate the near-field distribution of a cluster of nanocavities and that the results are in agreement with simulations by the finite element method and those measured by a scanning near-field optical microscope. The perturbation theory offers an effective way in dealing with the plasmonic coupling behavior of nanocavities. [ABSTRACT FROM AUTHOR]

Heterojunction catalysts in the field of hydrogen evolution reaction (HER) from electrocatalytic water splitting have recently become a hot research topic. In this paper, we systematically calculated the HER catalytic performance of a MoS2/CoS2 heterojunction for the first time, considering the effect of edge sites regulation, strain and electric field. The results indicate that the MoS2/CoS2 heterojunction exhibits synergistic catalytic performance compared to MoS2 and CoS2, the HER catalytic activity of which can be improved by exposing more edge sites or regulating the S content on the edges, with an optimized ratio of 25%. Surprisingly, applying strain has a slight effect on the catalytic activity of the edge, however, an obvious effect on the basal plane. For example, applying 2% tensile strain on the MoS2/CoS2 heterojunction can improve the edge catalytic performance by 13%, and for the basal plane, this value can reach 92%. In this case, the catalytic performance of the basal plane is better than that of the edge with 2% and without strain. Since the basal plane accounts for the majority of the two-dimensional catalysts, the catalytic performance of the basal plane is generally much lower than that of the edge. This discovery is of great significance, which means by adjusting strain, the catalytic performance of the heterojunction catalyst is likely to be improved by orders of magnitude. Moreover, considering the actual experimental process, we also calculated the effect of the electric field and found that 0.7 V/Å electric field can enhance the HER catalytic activity of the MoS2/CoS2 heterojunction by 23%. [ABSTRACT FROM AUTHOR]

The photochemical generation of nicotinamide cofactor 1,4-NADH, facilitated by inorganic photosensitizers, emerges as a promising model system for investigating charge transfer phenomena at the interface of semiconductors and bacteria, with implications for enhancing photosynthetic biohybrid systems (PBSs). However, extant semiconductor nanocrystal model systems suffer from achieving optimal conversion efficiency under visible light. This study investigates quasi-one-dimensional CdS nanorods as superior light absorbers, surface modified with catalyst Cp*Rh(4,4'-COOH-bpy)Cl2 to produce enzymatically active NADH. This model subsystem facilitates easy product isolation and achieves a turnover frequency (TOF) of 175 h-1, one of the highest efficiencies reported for inorganic photosensitizer-based nicotinamide cofactor generation. Charge transfer kinetics, fundamental for catalytic solar energy conversion, range from 106 to 108 s-1 for this system highlighting the superior electron transfer capabilities of NRs. This model ensures efficient cofactor production and offers critical insights into advancing systems that mimic natural photosynthesis for sustainable solar-to-chemical synthesis.

In pharmaceutical discovery, the "magic methyl" effect describes a substantial improvement in the pharmacological properties of a drug candidate with the incorporation of methyl groups. Therefore, to expedite the synthesis of methylated drug analogs, late-stage, undirected methylations of C(sp3)-H bonds in complex molecules would be valuable. However, current methods for site-selective methylations are limited to activated C(sp3)-H bonds. Here we describe a site-selective, undirected methylation of unactivated C(sp3)-H bonds, enabled by photochemically activated peroxides and a nickel(II) complex whose turnover is enhanced by an ancillary ligand. The methodology displays compatibility with a wide range of functional groups and a high selectivity for tertiary C-H bonds, making it suitable for the late-stage methylation of complex organic compounds that contain multiple alkyl C-H bonds, such as terpene natural products, peptides, and active pharmaceutical ingredients. Overall, this method provides a synthetic tool to explore the "magic methyl" effect in drug discovery.

Effective synthesis and application of single-atom catalysts on supports lacking enough defects remain a significant challenge in environmental catalysis. Herein, we present a universal defect-enrichment strategy to increase the surface defects of CeO2-based supports through H2 reduction pretreatment. The Pt catalysts supported by defective CeO2-based supports, including CeO2, CeZrOx, and CeO2/Al2O3 (CA), exhibit much higher Pt dispersion and CO oxidation activity upon reduction activation compared to their counterpart catalysts without defect enrichment. Specifically, Pt is present as embedded single atoms on the CA support with enriched surface defects (CA-HD) based on which the highly active catalyst showing embedded Pt clusters (PtC) with the bottom layer of Pt atoms substituting the Ce cations in the CeO2 surface lattice can be obtained through reduction activation. Embedded PtC can better facilitate CO adsorption and promote O2 activation at PtC-CeO2 interfaces, thereby contributing to the superior low-temperature CO oxidation activity of the Pt/CA-HD catalyst after activation.

Pt-based alloys, such as Pt3Ni, are among the best electrocatalysts for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells. Doping of PtNi alloys with Zr was shown to enhance the durability of the operating ORR catalysts. Rationalizing these observations is hindered by the absence of atomic-level data for these tri-metallic materials, even when not exposed to the fuel cell operation conditions. This study aims at understanding structure–property relations in Zr-doped PtNi nanoparticles as a key to their ORR function. In particular, we calculated, using a method based on density functional theory, the most stable chemical orderings of pristine and Zr-doped Pt3Ni particles containing over 400 atoms. We thus clarify (i) preferential location and charge states of Zr atoms in the Pt3Ni NPs; (ii) effect of doping Zr atoms on the stability of the Pt skin of the Pt3Ni NPs; (iii) charge redistribution induced by Zr dopants; (iv) layer-by-layer atomic ordering in the Pt3Ni/Zr NPs with the increasing Zr content; and (v) effect of Zr atoms on the adsorption energies of O and OH species as indicators of the ORR activity. [ABSTRACT FROM AUTHOR]

C4F7N [2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile]/CO2 gas mixtures are being developed as an eco-friendly electrical insulator to replace SF6, the most potent greenhouse industrial gaseous dielectric. However, recent studies have reported complicated and often conflicting decomposition pathways for C4F7N/CO2 gas mixtures, which has raised concerns. In this work, the decomposition characteristics of C4F7N/CO2 gas mixtures were studied comprehensively by both designed computations and experiments. Computations were performed starting from fundamental propositions of C4F7N/CO2 decompositions, which were further experimentally verified by pyrolysis, long-term thermal aging with/without catalytic materials (industrial-grade molecular sieves 4A), and electrical decomposition by spark discharge. The results of both computations and experiments suggest that in an ideal thermal decomposition, C4F7N is likely to decompose into C2F6 and small fluoronitriles first at high temperatures. The generation of C3F6 and C2N2 from C4F7N thermal decomposition at lower temperatures appears because of the catalytic effect of incompatible materials, for example, the industrial-grade molecular sieves 4A that we tested. The electron impact dissociation of C4F7N plays an important role in C4F7N electrical decomposition, leading to additional formation of distinctive small molecules of CF4 and C2N2 of low concentrations. It was pointed out based on a real arcing test in a load disconnector that the decomposition of C4F7N gas mixtures in real applications will be at a much moderate and manageable rate than what was obtained from the highly accelerated laboratory tests presented in this work. The signatures of decomposition products extracted in this study provide invaluable guidance for developing decomposition-based diagnosis and fixation of decomposition byproducts toward SF6-free power grids. [ABSTRACT FROM AUTHOR]

Rapid and precise detection of hydrogen peroxide (H2O2) holds great significance since it is linked to numerous physiological and inorganic catalytic processes. We herein developed a label-free and washing-free strategy to detect H2O2 by employing a hand-held personal glucose meter (PGM) as a signal readout device. By focusing on the fact that the reduced redox mediator ([Fe(CN)6]4-) itself is responsible for the final PGM signal, we developed a new PGM-based strategy to detect H2O2 by utilizing the target H2O2-mediated oxidation of [Fe(CN)6]4- to [Fe(CN)6]3- in the presence of horseradish peroxidase (HRP) and monitoring the reduced PGM signal in response to the target amount. Based on this straightforward and facile design principle, H2O2 was successfully determined down to 3.63 μM with high specificity against various non-target molecules. We further demonstrated that this strategy could be expanded to identify another model target choline by detecting H2O2 produced through its oxidation promoted by choline oxidase. Moreover, we verified its practical applicability by reliably determining extracellular H2O2 released from the breast cancer cell line, MDA-MB-231. This work could evolve into versatile PGM-based platform technology to identify various non-glucose target molecules by employing their corresponding oxidase enzymes, greatly advancing the portable biosensing technologies.

The ability to sense chemical gradients and respond with directional motility and chemical activity is a defining feature of complex living systems. There is a strong interest among scientists to design synthetic systems that emulate these properties. Here, we realize and control such behaviors in a synthetic system by tailoring multivalent interactions of adenosine nucleotides with catalytic microbeads. We first show that multivalent interactions of the bead with gradients of adenosine mono-, di- and trinucleotides (AM/D/TP) control both the phoretic motion and a proton-transfer catalytic reaction, and find that both effects are diminished greatly with increasing valence of phosphates. We exploit this behavior by using enzymatic hydrolysis of ATP to AMP, which downregulates multivalent interactivity in situ. This produces a sudden increase in transport of the catalytic microbeads (a phoretic jump), which is accompanied by increased catalytic activity. Finally, we show how this enzymatic activity can be systematically tuned, leading to simultaneous in situ spatial and temporal control of the location of the microbeads, as well as the products of the reaction that they catalyze. These findings open up new avenues for utilizing multivalent interaction-mediated programming of complex chemo-mechanical behaviors into active systems.

Electrochemical CO2 reduction (CO2R) using heterogenized molecular catalysts usually yields 2-electron reduction products (CO, formate). Recently, it has been reported that certain preparations of immobilized cobalt phthalocyanine (CoPc) produce methanol (MeOH), a 6-electron reduction product. Here, we demonstrate the significant role of intermediate mass transport in CoPc selectivity to methanol. We first developed a simple, physically mixed, polymer (and polyfluoroalkyl, PFAS)-free preparation of CoPc on multiwalled carbon nanotubes (MWCNTs) which can be integrated onto Au electrodes using a poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) adhesion layer. After optimization of catalyst preparation and loading, methanol Faradaic efficiencies and partial current densities of 36% (±3%) and 3.8 (±0.5) mA cm-2, respectively, are achieved in the CO2-saturated aqueous electrolyte. The electrolyte flow rate has a large effect. A linear flow velocity of 8.5 cm/min produces the highest MeOH selectivity, with higher flow rates increasing CO selectivity and lower flow rates increasing the hydrogen evolution reaction, suggesting that CO is an unbound intermediate. Using a continuum multiphysics model assuming CO is the intermediate, we show qualitative agreement with the optimal inlet flow rate. Polymer binders were not required to achieve a high Faradaic efficiency for methanol using CoPc and MWCNTs. We also investigated the role of formaldehyde as an intermediate and the role of strain, but definitive conclusions could not be established.

This year's Emerging Leader in Molecular Spectroscopy Award recipient is Joseph P. Smith of Merck, whose research is significantly influencing pharmaceutical process development through his work in various spectroscopic techniques, [...]

Enzymes accelerate the rates of biomolecular reactions by many orders of magnitude compared to bulk solution, and it is widely understood that this catalytic effect arises from a combination of polar pre-organization and electrostatic transition state stabilization. A number of recent reports have also implicated ultrafast (femtosecond-picosecond) timescale motions in enzymatic activity. However, complications arising from spatially-distributed disorder, the occurrence of multiple substrate binding modes, and the influence of hydration dynamics on solvent-exposed active sites still confound many experimental studies. Here we use ultrafast two-dimensional infrared (2D IR) spectroscopy and covalently-tethered substrate analogs to examine dynamical properties of the promiscuous Pyrococcus horikoshii ene-reductase (PhENR) active site in two binding configurations mimicking proposed "inactive" and "reactive" Michaelis complexes. Spectral diffusion measurements of aryl-nitrile substrate analogs reveal an end-to-end tradeoff between fast (sub-ps) and slow (>5 ps) motions. Fermi resonant aryl-azide analogs that sense interactions of coupled oscillators are described. Lineshape and quantum beat analyses of these probes reveal characteristics that correlate with aryl-nitrile frequency fluctuation correlation functions parameters, demonstrating that this anisotropy is an intrinsic property of the water-exposed active site, where countervailing gradients of fast dynamics and disorder in the reactant ground state are maintained near the hydration interface. Our results suggest several plausible factors leading to state-selective rate enhancement and promiscuity in PhENR. This study also highlights a strategy to detect perturbations to vibrational modes outside the transparent window of the mid-IR spectrum, which may be extended to other macromolecular systems. [ABSTRACT FROM AUTHOR]

Enzymes populate ensembles of structures necessary for catalysis that are difficult to experimentally characterize. We use time-resolved mix-and-inject serial crystallography at an x-ray free electron laser to observe catalysis in a designed mutant isocyanide hydratase (ICH) enzyme that enhances sampling of important minor conformations. The active site exists in a mixture of conformations, and formation of the thioimidate intermediate selects for catalytically competent substates. The influence of cysteine ionization on the ICH ensemble is validated by determining structures of the enzyme at multiple pH values. Large molecular dynamics simulations in crystallo and time-resolved electron density maps show that Asp17 ionizes during catalysis and causes conformational changes that propagate across the dimer, permitting water to enter the active site for intermediate hydrolysis. ICH exhibits a tight coupling between ionization of active site residues and catalysis-activated protein motions, exemplifying a mechanism of electrostatic control of enzyme dynamics.

Methods to access chiral sulfur(VI) pharmacophores are of interest in medicinal and synthetic chemistry. We report the desymmetrization of unprotected sulfonimidamides via asymmetric acylation with a cinchona-phosphinate catalyst. The desired products are formed in excellent yield and enantioselectivity with no observed bis-acylation. A data-science-driven approach to substrate scope evaluation was coupled to high throughput experimentation (HTE) to facilitate statistical modeling in order to inform mechanistic studies. Reaction kinetics, catalyst structural studies, and density functional theory (DFT) transition state analysis elucidated the turnover-limiting step to be the collapse of the tetrahedral intermediate and provided key insights into the catalyst-substrate structure-activity relationships responsible for the origin of the enantioselectivity. This study offers a reliable method for accessing enantioenriched sulfonimidamides to propel their application as pharmacophores and serves as an example of the mechanistic insight that can be gleaned from integrating data science and traditional physical organic techniques.

The high-fidelity (HF1), hyper-accurate (Hypa), and evolved (Evo) variants of the CRISPR-associated protein 9 (Cas9) endonuclease are critical tools to mitigate off-target effects in the application of CRISPR-Cas9 technology. The mechanisms by which mutations in recognition subdomain 3 (Rec3) mediate specificity in these variants are poorly understood. Here, solution nuclear magnetic resonance and molecular dynamics simulations establish the structural and dynamic effects of high-specificity mutations in Rec3, and how they propagate the allosteric signal of Cas9. We reveal conserved structural changes and dynamic differences at regions of Rec3 that interface with the RNA:DNA hybrid, transducing chemical signals from Rec3 to the catalytic His-Asn-His (HNH) domain. The variants remodel the communication sourcing from the Rec3 α helix 37, previously shown to sense target DNA complementarity, either directly or allosterically. This mechanism increases communication between the DNA mismatch recognition helix and the HNH active site, shedding light on the structure and dynamics underlying Cas9 specificity and providing insight for future engineering principles.

CRISPR-Cas12a is a powerful RNA-guided genome-editing system that generates double-strand DNA breaks using its single RuvC nuclease domain by a sequential mechanism in which initial cleavage of the non-target strand is followed by target strand cleavage. How the spatially distant DNA target strand traverses toward the RuvC catalytic core is presently not understood. Here, continuous tens of microsecond-long molecular dynamics and free-energy simulations reveal that an α-helical lid, located within the RuvC domain, plays a pivotal role in the traversal of the DNA target strand by anchoring the crRNA:target strand duplex and guiding the target strand toward the RuvC core, as also corroborated by DNA cleavage experiments. In this mechanism, the REC2 domain pushes the crRNA:target strand duplex toward the core of the enzyme, while the Nuc domain aids the bending and accommodation of the target strand within the RuvC core by bending inward. Understanding of this critical process underlying Cas12a activity will enrich fundamental knowledge and facilitate further engineering strategies for genome editing.

Electron bifurcation (BF) is an evolutionarily ancient energy coupling mechanism in anaerobes, whose associated enzymatic machinery remains enigmatic. In BF-flavoenzymes, a chemically high-potential electron forms in a thermodynamically favorable fashion by simultaneously dropping the potential of a second electron before its donation to physiological acceptors. The cryo-EM and spectroscopic analyses of the BF-enzyme Fix/EtfABCX from Thermotoga maritima suggest that the BF-site contains a special flavin-adenine dinucleotide and, upon its reduction with NADH, a low-potential electron transfers to ferredoxin and a high-potential electron reduces menaquinone. The transfer of energy from high-energy intermediates must be carefully orchestrated conformationally to avoid equilibration. Herein, anaerobic size exclusion-coupled small-angle X-ray scattering (SEC-SAXS) shows that the Fix/EtfAB heterodimer subcomplex, which houses BF- and electron transfer (ET)-flavins, exists in a conformational equilibrium of compacted and extended states between flavin-binding domains, the abundance of which is impacted by reduction and NAD(H) binding. The conformations identify dynamics associated with the T. maritima enzyme and also recapitulate states identified in static structures of homologous BF-flavoenzymes. Reduction of Fix/EtfABCX's flavins alone is insufficient to elicit domain movements conducive to ET but requires a structural "trigger" induced by NAD(H) binding. Models show that Fix/EtfABCX's superdimer exists in a combination of states with respect to its BF-subcomplexes, suggesting a cooperative mechanism between supermonomers for optimizing catalysis. The correlation of conformational states with pathway steps suggests a structural means with which Fix/EtfABCX may progress through its catalytic cycle. Collectively, these observations provide a structural framework for tracing Fix/EtfABCX's catalysis.

Mutations in the RNA helicase DDX3X, implicated in various cancers and neurodevelopmental disorders, often impair RNA unwinding and translation. However, the mechanisms underlying the impairment and the differential interactions of DDX3X mutants with wild-type (WT) X-linked DDX3X and Y-linked homolog DDX3Y remain elusive. This study reveals that specific DDX3X mutants more frequently found in disease form distinct hollow condensates in cells. Using a combined structural, biochemical, and single-molecule microscopy study, we show that reduced ATPase and RNA release activities contribute to condensate formation and these catalytic deficits result from inhibiting the catalytic cycle at multiple steps. Proteomic investigations further demonstrate that these hollow condensates sequester WT DDX3X/DDX3Y and other proteins crucial for diverse signaling pathways. WT DDX3X enhances the dynamics of heterogeneous mutant/WT hollow condensates more effectively than DDX3Y. These findings offer valuable insights into the catalytic defects of specific DDX3X mutants and their differential interactions with wild-type DDX3X and DDX3Y, potentially explaining sex biases in disease.

Calcium carbonate (CaCO3) is an incredibly abundant mineral on Earth, with over 90% of it being found in the lithosphere. To address the CO2 crisis and combat ocean acidification, it is essential to produce more CaCO3 using various synthetic methods. Additionally, this approach can serve as a substitute for energy-intensive processes like cement production. By doing so, we have the potential to not only reverse the damage caused by climate change but also protect biological ecosystems and the overall environment. The key lies in maximizing the utilization of CaCO3 in various human activities, paving the way for a more sustainable future for our planet.

Mechanochemistry, a solvent-free approach that harnesses mechanical energy, is emerging as a transformative technique in modern chemistry. It has emerged from a niche technique to a versatile tool with broad applications. By inducing physical and chemical transformations, it enables the synthesis of complex molecules and nanostructured materials. Recent advancements have extended its applications beyond simple physical transformations to encompass catalytic processes, unlocking new possibilities for selective synthesis and product design. This account delves into the fundamentals of mechanochemistry and its applications in organic synthesis, also beyond traditional synthetic routes. Mechanochemistry offers new avenues for molecular and materials discovery, expanding the scope of accessible chemical space. 1 Introduction 2 Organic Synthesis in Ball Mills 3 Combination with Different Energy Sources 4 Advantages of Mechanochemistry 5 Future of Mechanochemistry 6 Conclusion [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Chiral phosphine‐catalyzed asymmetric (4+2) annulation of the amide‐based Morita–Baylis–Hillman (MBH) carbonates with β,γ‐unsaturated butenolides has been developed to give enantiomer‐enriched bicyclic δ‐lactam γ‐butyrolactone compounds. The amide‐based MBH carbonates were first used as acceptor and aza‐C4 synthon in phosphine catalysis. Under mild reaction conditions, a variety of amide‐based MBH carbonates and unsaturated butenolides were well tolerated to provide chiral bicyclic δ‐lactam γ‐butyrolactone derivatives in high yields with excellent enantioselectivities as well as diastereoselectivities. A plausible reaction mechanism was also proposed based on control experiments and DFT calculations. [ABSTRACT FROM AUTHOR]

Enzymes are natural treasure troves that hold multiple superiority. Enzymatic catalysis has become a powerful tool for asymmetric synthesis, though it is typically limited to a relatively narrow range of reaction types. By integrating the advantages of enzymatic catalysis with photocatalysis, photoenzymatic catalysis not only expands the catalytic capabilities of enzymes but also provides an effective strategy for the stereo‐control of photochemical reactions, thereby emerging as a significant research field. Herein, we focus on new‐to‐nature photoenzymatic catalysis by repurposing naturally occurring enzymes with visible light. We highlight the seminal work in reshaping various classes of enzymes, emphasizing their catalytic mechanism and synthetic potentials. Early Day Record: [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Boronate esters are highly valued in synthetic and pharmaceutical industries for their versatility in creating C—C and C—X bonds. They also find applications as catalysts in chemical transformations as well as stimuli‐responsive materials in materials science. Some alkyl boronates themselves also show promising applications in medicinal chemistry. In the past few decades, chemists have been devoted to developing new methods or new starting materials for synthesizing boronate esters. Carboxylic acids and their derivatives are privileged chemical entities due to their readily availability or natural abundance, structural diversity, and chemical stability. Hence, the transformation of carboxylic acid and their derivatives to alkyl/aryl boronate esters has seen its fast development in the past decade. This review summarized the state‐to‐art development of decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives to aryl and alkyl boronate esters. Key Scientists: The decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives started only in the past decade. In 2016, the decarbonylative borylation of carboxylic esters and amides was reported by Zhuangzhi Shi and Magnus Reuping's groups. Then, in 2017, studies on the decarboxylative borylation of redox‐active esters such as NHPI esters started to receive increasing attention by Aggarwal, Baran, Fu, Glorius, and Li's groups. From 2018 to 2023, large numbers of studies on the decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives using transition‐metal‐catalyst, organo‐catalyst, or under photochemical or electrochemical conditions emerged. Due to space limitations, only pictures of scientists who have contributed more than two works in this area are shown herein. [ABSTRACT FROM AUTHOR]

Sulfonyl fluorides hold significant importance as highly valued intermediates in chemical biology due to their optimal balance of biocompatibility with both aqueous stability and protein reactivity. The Cornella group introduced a one‐pot strategy for synthesizing aryl sulfonyl fluorides via Bi(III) redox‐neutral catalysis, which facilitates the transmetallation and direct insertion of SO2 into the BiC(sp2) bond giving the aryl sulfonyl fluorides. We report herein a comprehensive computational investigation of the redox‐neutral Bi(III) catalytic mechanism, disclose the critical role of the Bi(III) catalyst and base (i.e., K3PO4), and uncover the origin of SO2 insertion into the Bi(III)C(sp2) bond. The entire catalysis can be characterized via three stages: (i) transmetallation generating the Bi(III)‐phenyl intermediate IM3 facilitated by K3PO4. (ii) SO2 insertion into IM3 leading to the formation of Bi(III)‐OSOAr intermediate IM5. (iii) IM5 undergoes S(IV)‐oxidation yielding the aryl sulfonyl fluoride product 4 and liberating the Bi(III) catalyst for the next catalytic cycle. Each stage is kinetically and thermodynamically feasible. Moreover, we explored other some small molecules (NO2, CO2, H2O, N2O, etc.) insertion reactions mediated by the Bi(III)‐complex, and found that NO2 insertions could be easily achieved due to the low insertion barriers (i.e., 17.5 kcal/mol). Based on the detailed mechanistic study, we further rationally designed additional Bi(III) and Sb(III) catalysts, and found that some of which exhibit promising potential for experimental realization due to their low barriers (<16.4 kcal/mol). In this regard, our study contributes significantly to enhancing current Bi(III)‐catalytic systems and paving the way for novel Bi(III)‐catalyzed aryl sulfonyl fluoride formation reactions. [ABSTRACT FROM AUTHOR]

Nitrogenases are the only enzymes that activate the strong triple bond in N2. The mechanism for the activation has been very difficult to determine in spite of decades of work. In previous modeling studies it has been suggested that the mechanism for nitrogen activation starts out by four pre‐activation steps (A0–A4) before catalysis. That suggestion led to excellent agreement with experimental Elecrtron Paramagnetic Resonance (EPR) observations in the step where N2 becomes protonated (E4). An important part of the pre‐activation is that a sulfide is released. In the present paper, the details of the pre‐activation are modeled, including the release of the sulfide. Several possible transition states for the release have been obtained. An A4(E0) state is reached which is very similar to the E4 state. For completeness, the steps going back from A4(E0) to A0 after catalysis are also modeled, including the insertion of a sulfide. [ABSTRACT FROM AUTHOR]

Au@Pt core-satellite nanoparticles (CSNPs) with dual-functionality as both catalyst and surface-enhanced Raman scattering (SERS) substrate are successfully synthesized by decorating Pt nanocrystals on plasmonic Au colloids. The coupling "hotspot" structures at the Au-Pt interface significantly promotes the catalytic decarboxylation reaction, and provides spectroscopic insights into the molecule-plasmon interface in universal plasmon-promoted catalytic reactions. [Display omitted] Plasmon-induced hot carriers are a promising "active" energy source, attracting increasing attention for their potential applications in photocatalysis and photodetection. Here, we hybridize plasmonic Au spherical nanoparticles (SNPs) with catalytically active Pt nanocrystals to form Au@Pt core-satellite nanoparticles (CSNPs), which act as both an efficient catalyst for plasmon-promoted decarboxylation reaction and a robust surface-enhanced Raman scattering (SERS) substrate for plasmon-enhanced molecular spectroscopic detection. By regulating the coverage of Pt nanocrystals on the Au SNPs, we modulated the "hotspot" structures of the Au@Pt CSNPs to optimize the SERS detecting capability and catalytic decarboxylation performance. The coupling functionalities enable us with unique opportunities to in-situ SERS monitor universal reactions catalyzed by active catalysts (e.g. Pt, Pd) in the chemical industry in real-time. The decarboxylation rate of 4-mercaptophenylacetic acid was dynamically controlled by the surface catalytic decarboxylation step, following first-order overall reaction kinetics. Moreover, the reaction rate exhibited a strong correlation with the local field enhancement |E/E 0 |4 of the hotspot structure. This work provides spectroscopic insights into the molecule-plasmon interface under the plasmon-promoted catalytic reactions, guiding the rational design of the plasmonic interface of nanocatalysts to achieve desired functionalities. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Chiral phosphine‐catalyzed asymmetric (4+2) annulation of the amide‐based Morita–Baylis–Hillman (MBH) carbonates with β,γ‐unsaturated butenolides has been developed to give enantiomer‐enriched bicyclic δ‐lactam γ‐butyrolactone compounds. The amide‐based MBH carbonates were first used as acceptor and aza‐C4 synthon in phosphine catalysis. Under mild reaction conditions, a variety of amide‐based MBH carbonates and unsaturated butenolides were well tolerated to provide chiral bicyclic δ‐lactam γ‐butyrolactone derivatives in high yields with excellent enantioselectivities as well as diastereoselectivities. A plausible reaction mechanism was also proposed based on control experiments and DFT calculations. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Boronate esters are highly valued in synthetic and pharmaceutical industries for their versatility in creating C—C and C—X bonds. They also find applications as catalysts in chemical transformations as well as stimuli‐responsive materials in materials science. Some alkyl boronates themselves also show promising applications in medicinal chemistry. In the past few decades, chemists have been devoted to developing new methods or new starting materials for synthesizing boronate esters. Carboxylic acids and their derivatives are privileged chemical entities due to their readily availability or natural abundance, structural diversity, and chemical stability. Hence, the transformation of carboxylic acid and their derivatives to alkyl/aryl boronate esters has seen its fast development in the past decade. This review summarized the state‐to‐art development of decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives to aryl and alkyl boronate esters. Key Scientists: The decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives started only in the past decade. In 2016, the decarbonylative borylation of carboxylic esters and amides was reported by Zhuangzhi Shi and Magnus Reuping's groups. Then, in 2017, studies on the decarboxylative borylation of redox‐active esters such as NHPI esters started to receive increasing attention by Aggarwal, Baran, Fu, Glorius, and Li's groups. From 2018 to 2023, large numbers of studies on the decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives using transition‐metal‐catalyst, organo‐catalyst, or under photochemical or electrochemical conditions emerged. Due to space limitations, only pictures of scientists who have contributed more than two works in this area are shown herein. [ABSTRACT FROM AUTHOR]

A method to obtain sodium titanate nanoribbons starting from a mixture of brookite and anatase TiO₂ nanopowder is described. As-prepared TiO 2 nanopowder with a major brookite phase was used as a precursor in an alkaline hydrothermal approach, where the temperature was kept at 200 °C. The influence of hydrothermal treatment and consequent annealing temperature (T = 500 °C) on the crystal structure, phase composition, and morphology of samples were investigated by X-ray powder diffraction (XRPD), Raman and FTIR spectroscopy, and electron microscopy techniques (FESEM, HRTEM). All these methods point out that the hydrothermally treated sample, containing the NaTi 3 O 6 (OH)(H 2 O) 2 , Na 2 Ti 3 O 7 , and Na 2 Ti 9 O 19 , is dominated by layer-structured sodium hydroxititanate dihydrate. The annealing leads to the formation of rare sodium titanates, Na 3 Ti 6 O 13 and Na 2 Ti 9 O 19 , with tunnel structures where the hexatitanate with increased sodium content prevails. The photocatalytic activity of synthesized nanostructures was tested in the degradation process of Reactive Orange (RO16) azo-dye upon UV excitation. It appears that photocatalytic activity is lower after hydrothermal treatment, but subsequent annealing makes sodium titanate nanoribbons faster in the degradation of RO16. The research implies that these sodium titanate nanostructures are promising photocatalytic materials and should be considered in the future for removing different pollutants from water. [ABSTRACT FROM AUTHOR]

The present computational study provides a benchmark of density functional theory (DFT) methods in describing hydrogen evolution processes catalyzed by [Cp*Rh]‐containing organometallic complexes. A test set was composed of 26 elementary reactions featuring chemical transformations and bonding situations essential for the field, including the emerging concept of non‐innocent Cp* behavior. Reference values were obtained from a highly accurate 3/4 complete basis set and 6/7 complete PNO space extrapolated DLPNO‐CCSD(T) energies. The performance of lower‐level extrapolation procedures was also assessed. We considered 84 density functionals (DF) (including 13 generalized gradient approximations (GGA), nine meta‐GGAs, 33 hybrids, and 29 double‐hybrids) and three composite methods (HF‐3c, PBEh‐3c, and r2SCAN‐3c), combined with different types of dispersion corrections (D3(0), D3BJ, D4, and VV10). The most accurate approach is the PBE0‐DH‐D3BJ (MAD of 1.36 kcal mol−1) followed by TPSS0‐D3BJ (MAD of 1.60 kcal mol−1). Low‐cost r2SCAN‐3c composite provides a less accurate but much faster alternative (MAD of 2.39 kcal mol−1). The widely used Minnesota‐family M06‐L, M06, and M06‐2X DFs should be avoided (MADs of 3.70, 3.94, and 4.01 kcal mol−1, respectively). [ABSTRACT FROM AUTHOR]

There is increasing interest in the discovery and application of molecular flasks–supramolecular host structures capable of catalyzing organic reactions. Reminiscent of enzymes due to possessing a host cavity akin to an active site, molecular flasks can exhibit complex catalytic mechanisms and in many cases provide selectivity not achievable in bulk solvent. In this Review, we aim to organize the increasingly diverse examples through a two‐part structure. In part one, we provide an overview of the different acceleration modes that operate within molecular flasks, while in part two we showcase, through selected examples, the different types of selectivity that are obtainable through the use of molecular flasks. Particular attention is given to examples that are relevant to current challenges in synthetic organic chemistry. We believe that this structure makes the field more approachable and thus will stimulate the development of novel applications of molecular flasks. [ABSTRACT FROM AUTHOR]

The electrochemical hydrogenation (e‐hydrogenation) of unsaturated compounds like imines or carbonyls presents a benign reduction method. It enables direct use of electrons as reducing agent, water as proton source, while bypassing the need for elevated temperatures or pressures. In this contribution, we discuss the active species in electrocatalytic reductive amination with the transformation of acetone and methylamine as model reaction. Surprisingly, lead impurities in the ppm‐range proved to possess a significant effect in e‐hydrogenation. Accordingly, the influence of applied potential and cathode material in presence of 1 ppm Pb was investigated. Finally, we transferred the insights to the reduction of acetone manifesting comparable observations as for imine reduction. The results suggest that previous studies on electrochemical reduction in the presence of lead electrodes should be re‐evaluated. [ABSTRACT FROM AUTHOR]

Organoboron compounds are widely utilized in organic synthesis for their diverse reactivity, modular preparation, and stability compared to other classes of organometallic reagents. While organoboron species are commonly employed as nucleophiles in cross‐coupling reactions, their potential as racemic building blocks in enantioconvergent transformations remains largely untapped. Herein, we demonstrate the direct utilization of alkylboronic pinacol esters in intermolecular enantioconvergent transformations. Specifically, this work describes the development and mechanistic study of an enantioconvergent deborylative cyanation enabled by Cu catalysis. This method imparts a high degree of enantioselectivity and tolerates a wide range of common functional groups and heterocycles. The reaction is proposed to proceed through a radical‐relay mechanism. Aniline‐assisted homolysis of the carbon–boron bond results in prochiral alkyl radicals that are functionalized by in situ generated Cu(II)(CN)2 species in an enantioselective fashion. The Cu(II)(CN)2 intermediate was characterized by electron paramagnetic resonance (EPR) spectroscopy, and its electronic structure was probed using density functional theory (DFT) calculations. Computational studies were carried out to corroborate the proposed radical‐relay mechanism. [ABSTRACT FROM AUTHOR]

Unlike the well-established fluoroalkylation, the direct incorporation of multiple fluorine atoms into small molecules via iterative fluorinations has been much less investigated. Herein, we report a hypervalent iodine catalytically selective multi-fluorination in which the fluorination degree is controlled by the delicate balance between the HF/amine ratios. The pros and cons of hypervalent iodine catalysis and the previously established electrochemical approach in the iterative multi-fluorinations are also provided. [ABSTRACT FROM AUTHOR]

In this study, a thermally stable spherical NiMOF was introduced into MgH 2 to enhance its hydrogen storage performance. The NiMOF was synthesized via a solvothermal method, and MgH 2 -x wt.% NiMOF (x = 3, 5, 10, 15) composites were prepared by ball milling. The MgH 2 -10 wt% NiMOF composite showed the best performance, with a maximum hydrogen storage capacity of 6.4 wt% under 4.2 MPa at 548 K. It absorbed 4.0 wt% H 2 in 5 min and 5.2 wt% in 30 min at 548 K and 3.1 MPa. The composite demonstrated excellent cyclic stability, retaining 5.0 wt% capacity after 10 cycles. Activation energies were 64.74 kJ/mol for hydrogenation and 119.596 kJ/mol for dehydrogenation. Major highlights of this study. (1) The thermally stable NiMOF material can withstand temperatures up to 709 K. (2) NiMOF enhances the hydrogen absorption and desorption kinetics of MgH 2. (3) The stable structure of NiMOF imparts excellent cycling stability to the material. [ABSTRACT FROM AUTHOR]

Exploiting magnesium-based hydrogen storage materials faces great challenges due to their inherent thermodynamic and kinetic characteristics. However, this issue can be mitigated by employing a catalyst doping modification strategy. In this work, a composite of titanium carbide (Ti 3 C 2 T x MXene)-supported nickel fluoride (NiF 2) nanoparticles, known as NiF 2 @Ti 3 C 2 , was fabricated via the hydrothermal approach and utilized to reinforce the hydrogen storage performance of magnesium (Mg). It was shown that NiF 2 @Ti 3 C 2 composites have exceptional catalytic properties for Mg hydrogen storage. The Mg–NiF 2 @Ti 3 C 2 composite, containing 5 wt% of NiF 2 @Ti 3 C 2 , released 3.46 wt% of hydrogen at 300 °C, while pure Mg produced essentially little hydrogen in identical conditions. Additionally, there was a decrease in the activation energy of hydrogen desorption from 135.4 to 77.65 kJ mol−1. Moreover, the composite offered excellent stability and reversible performance, achieving 95.8% capacity retention after 10 consecutive testing cycles. During the hydrogen uptake and release process, the NiF 2 @Ti 3 C 2 composite interacted with Mg/MgH 2 to produce the metals Ti0, MgF 2 , and Mg 2 Ni/Mg 2 NiH 4 , which acted as active species to boost the hydrogen storage performance of Mg. • Ti 3 C 2 T x supported NiF 2 nanoparticles composite is prepared via hydrothermal method. • Dehydrogenation kinetics and reversibility of Mg were improved by NiF 2 @Ti 3 C 2. • In situ-formed multiphase metals synergistically accelerate the release of H 2. [ABSTRACT FROM AUTHOR]

A Fe(OTf)3 and γ-cyclodextrin-catalyzed hydroarylation of alkenes with 1-naphthols or 2-naphthols is demonstrated. This efficient and general method delivers a wide range of benzylic naphthols from readily available starting materials with high chemo- and regioselectivity in up to 99% yield, with no need for a strong base or additive. [ABSTRACT FROM AUTHOR]

Over the past years our lab has established a research program towards the late-stage introduction of deuterium into organic molecules using Pd-catalyzed reversible C–H activation as a means to affect hydrogen isotope exchange. Through catalyst design, including the introduction of novel ligand scaffolds, as well as the use of strategically chosen optimization and screening approaches, e.g., exploiting microscopic reversibility by first optimizing de-deuteration processes or using a multi-substrate screening approach, our studies have resulted in a number of synthetically useful labelling protocols and are described herein from a personal perspective. 1 Introduction 2 β-C(sp3)–H Deuteration of Free Carboxylic Acids 3 Nondirected C–H Deuteration of Arenes 4 Nondirected C–H Deuteration of Heteroarenes 5 Conclusion [ABSTRACT FROM AUTHOR]

The different topics and synthetic approaches in an isotope chemistry laboratory of a pharma company are described. Besides the challenges in the synthesis of long-lived isotopes such as3 H or14 C, short-lived isotopes such as68 Ga and stable isotopes such as15 N,13 C or2 H approaches for the isotopic labeling are also demonstrated. Furthermore, method development with emphasis on collaborations with academic groups to tackle the future challenges are discussed. 1 Introduction 2 Isotopic Labeling with Hydrogen Isotopes Deuterium (2 H, D) and Tritium (3 H, T) 2.1 Deuterium Labeling for MS Standards 2.1.1 Labeled Nitrosamines – The Hunt to Quantify Hazardous Impurities 2.1.2 Deuterated Drugs, an Approach To Improve Existing Drugs or To Find Opportunities in Drug Discovery 2.2 Tritium-Labeling Methods – The Fast Approach to Radioactively Labeled Compounds 2.2.1 Hydrogen Isotope Exchange by Iridium Catalysis 2.2.2 Ruthenium-Catalyzed HIE 2.2.3 Nanoparticles as Catalysts in HIE 2.2.4 Photoredox-Catalyzed HIE 2.2.5 HIE via Classical Radical Mechanism 2.2.6 Beyond HIE – Halogen–Tritium Exchange 3 Challenges in14 C-Synthesis Projects 4 Short-Lived Isotopes – The Need for Speed 5 Beyond Isotope Science – Late-Stage Functionalization 5.1 Examples of Late-Stage Functionalization for Peptides 5.2 Examples of Catalyst-Controlled Late-Stage Functionalization 6 Conclusion [ABSTRACT FROM AUTHOR]

A simple, direct, and regioselective protocol to substituted 5-iodo-4 H -quinoxalines through double C–N arylations of 1,2,3-triiodobenzenes and 1,2-diamines is reported. Remarkably, the N-arylation couplings proceed unimolecularly at the vicinal positions, the most active and less hindered positions. This process tolerates a wide range of aromatic substrates. The reactions of electron-deficient 1,2,3-triiodoarene systems and DMEDA under the optimized conditions provided the highest isolated yields. The chemical transformation of the target compound, which serves as a valuable precursor in synthesis, was successfully demonstrated in the Suzuki–Miyaura reaction, giving the desired coupling derivatives with excellent isolated yields. This article describes a method for the first and unprecedented synthesis of 5-iodo-4 H -quinoxalines that is regioselective, scalable, and provides useful derivatives for other chemical reactions [ABSTRACT FROM AUTHOR]

Palladium- and nickel-catalyzed cross-couplings are powerful methods for constructing C–C and C–N bonds, particularly through Suzuki–Miyaura and Buchwald–Hartwig reactions. Although aryl iodides, bromides, and triflates are the most commonly used substrates, aryl chlorides are less frequently utilized due to their lower reactivity. However, they are appealing because they are readily available and inexpensive. This short review highlights recent developments on the Suzuki–Miyaura and Buchwald–Hartwig cross-couplings of aryl chlorides, using both homogeneous and heterogeneous catalysis with palladium and nickel. 1 Introduction 2 Suzuki–Miyaura Cross-Couplings 2.1 Homogeneous Palladium Catalysis 2.2 Heterogeneous Palladium Catalysis 2.3 Homogeneous Nickel Catalysis 2.4 Heterogeneous Nickel Catalysis 3 Buchwald–Hartwig Amination Reactions 3.1 Homogeneous Palladium Catalysis 3.2 Heterogeneous Palladium Catalysis 3.3 Homogeneous Nickel Catalysis 3.4 Heterogeneous Nickel Catalysis 4 Conclusion [ABSTRACT FROM AUTHOR]

Thiourea is a low-toxicity gold lixiviant that has promise to substitute highly toxic cyanide for gold extraction. The electrochemical behavior of lead ion in the dissolution of gold in thiourea solution was investigated by electrochemical and analytical technique. Electrochemical results suggest that the addition of lead ion (10 mg/L and 20 mg/L) to thiourea solution increased the open circuit potential from 0.31 V to 0.32 V and 0.34 V, respectively, due to the significant increase of cathodic current density. The presence of lead ion could significantly improve the oxidative dissolution of gold and thus resulted in higher gold dissolution in thiourea solution, particularly at higher anodic potentials. The scanning electron microscope (SEM) equipped with energy dispersive spectroscope (EDS) and X-ray photoelectrode spectroscopy (XPS) analyses indicate the improvement of gold dissolution is attributed to the formation of gold-lead (AuPb2) layer on gold surface, which acts as a cathode to promote galvanic corrosion of gold. The possible mechanism is proposed that gold dissolution in thiourea solution with lead ion follows a two-step process: (1) the formation of AuPb2 layer on gold surface and (2) the dissolution of AuPb2 layer under the applied anodic potential. [ABSTRACT FROM AUTHOR]

Phosphorus is an essential element influencing both food security via plant fertilization, and water pollution through excessive phosphorus use, yet the phosphorus cycle in ecosystems is poorly known. In particular, beyond adsorption, the role of iron and manganese oxides in catalyzing the abiotic dephosphorylation of biomolecules is debated. Here, we studied the reactions of ribonucleotides, containing different phosphate bonding, with goethite, hematite, and birnessite. We employed both high-resolution mass spectrometry of solution species and molecular modeling simulations of ribonucleotide-mineral complexes. Results disclose an up to fivefold preferential hydrolytic cleavage of a phosphoanhydride bond over a phosphoester bond, indicating that mineral-catalyzed reactions reflect the hierarchy reported for the activity of phosphatase enzymes. The fourfold higher catalytic reactivity of goethite and birnessite versus hematite is explained by mineral-specific binding rather than surface area differences. Corresponding simulated adsorbate conformations at the water–mineral interfaces are proposed. Overall, our findings provide new insights on the catalytic recycling of organic phosphorus species by mineral oxides. [ABSTRACT FROM AUTHOR]

This review discusses the synthesis, characterization, catalytic applications, mechanisms, current advances, challenges, and environmental consequences of Graphene oxide-based ferrite nanocomposites. The synthesis described the strategies used to synthesize these nanocomposites. The structural characterization was discussed using XRD, FTIR, and Raman spectroscopy techniques and how it could learn about their chemical composition and bonding. Morphological characterization said the results obtained on the nanostructure of these nanocomposites. The catalytic application phase is concerned with their use in photocatalysis, electrocatalysis, and magnetic catalysis, as well as the synergistic impact and the extra suitable electron switch pathways. The assessment also highlighted emerging developments in synthesis, novel catalytic applications, and capacity applications. The challenges and destiny directions discussed the importance of particular synthesis, management, balance, enhancement, and scalability. Compared to the sustainability, economic viability, and ecological effect, the environmental and monetary issues section underlined the significance of environmentally pleasant manufacturing and massive-scale viability. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) have overcome solutions to problems associated with increased production with sustainable green approaches over the last three decades. Ionic liquids have appeared as a significant alternative to traditional organic solvents in metal-catalyzed reactions in organic synthesis. This substitution has proven to be instrumental in promoting sustainable development goals by facilitating an eco-friendlier approach to chemical synthesis. Carbon- carbon (C–C) cross-coupling reactions have a decisive role in organic and inorganic chemistry, acting as a flexible tool for the synthesis of complex molecules and materials. These reactions find their applications in various fields, including natural products, pharmaceuticals, and polymers. Among the most frequently used methods for C–C bond formation are the Heck and Suzuki reactions. In this review, we have examined and discussed the recent advancements in the use of ILs as solvents and catalysts in Heck and Suzuki reactions. We have explored various factors such as conversion, yield, catalyst recovery, and time reaction in the context of these reactions over the past few decades. The advantages and accomplishments of using ionic liquids have been evaluated with respect to their potential for enhancing the efficiency of industrial processes. [ABSTRACT FROM AUTHOR]

Vitamins are not only essential for normal cell function but also important in organic transformations, specifically in the field of organocatalysis. Due to the increasing importance of sustainable and ecofriendly organic reaction protocols, there has been growing attention in organocatalysis owing to easy access, biocompatibility, and excellent reactivity. As vitamins are environmentally benign, nontoxic, and economic organocatalyst, VB1, VB2, and VB12 have been employed successfully in variety of organic transformations. The catalysts exhibited very high efficacy in various C–C bond-forming reactions from multicomponent reaction to cross-coupling reactions. This review concisely demonstrates catalytic performance of natural organocatalyst VB1, VB2, and VB12 and also provides basic knowledge about this important synthetic tool for the preparation of organic compounds in a greener manner. The review explores the versatile application of vitamins where vitamins acted as the principal catalyst (Lewis acidic catalyst, photocatalyst), co-catalyst, organometallic catalyst, and ligand of metal ion catalysts. Utilization of vitamin-functionalized nanocatalysts in cross-coupling, A3-coupling, oxidation reaction, etc. has been demonstrated thoroughly. Additionally, the mechanistic details illuminating the roles of vitamins in important organic transformations are meticulously explained, providing insights into reaction pathways and empowering the described organcatalysis approaches. [ABSTRACT FROM AUTHOR]

Emulsions are dispersed systems widely used in various industries. In recent years, Raman spectroscopy (RS), as a spectroscopic technique, has gained much attention for measuring and monitoring emulsions. In this review, we explore the use of RS on emulsion structures and emulsification, important reactions that use emulsions such as emulsion polymerization, catalysis and cascading reactions, as well as various applications of emulsions. We explore how RS is used in emulsions, reactions and applications. RS is a powerful and versatile tool for studying emulsions, but there are also challenges in using RS to monitor emulsion processes, especially if they are rapid or volatile. We also explore these challenges and difficulties, as well as possible designs that can be used to overcome them. [ABSTRACT FROM AUTHOR]