Reaction Of Reagents Research Articles

Epidemiology of Acute Infectious Diarrhea-Associated Viruses in Children in Hangzhou, China, 2023

Abstract Objective To investigate the epidemiological characteristics of children infected with diarrheal virus in Hangzhou, China, 2023. Methods From January 2023 to December 2023, 20,939 stool samples from children with acute infectious diarrhea were collected for the detection of rotavirus A and human adenovirus (HAdV), using latex agglutination detection kits; 7,584 stool samples were collected for the detection of norovirus, using real-time polymerase chain reaction reagent. Results A total of 639 (3.0%, 639/20,939) tested positive for rotavirus A, and 1,201 (5.7%, 1,201/20,939) positive samples were detected by colloidal gold method. The positive rates of norovirus were 42.2% (3,203/7,585). Among all age groups, the rotavirus A positive detection rate was the highest in participants aged 3 to 6 years (6.46%, 260/4,024). The monthly distribution of patients with rotavirus A showed that the number of cases was the lowest in October (0.45%, 8/1,779) and reached the peak in April (7.97%, 144/1,806). The highest and lowest positive rates among all age groups for HAdV were found in children aged 3 to 6 years(8.27%, 333/4,024) and in those aged 0 to 6 months (2.21%, 60/2,717). The monthly positivity rates of HAdV spanning from January to November 2023 were 1.38, 1.44, 2.34, 3.65, 6.64, 7.71, 7.54, 7.13, 6.82, 4.15, and 6.50%, and reached the peak in December (8.17%). For norovirus, children aged 1 to 3 years had the highest positive detection rate (57.95%, 1,349/2,328), while infants aged 0 to 6 months had the lowest positive detection rate (19.60%, 205/1,046). The results show that January had the lowest number of cases (14.63%, 6/41), while September had the highest (50.51%, 545/1,079). Conclusion The detection rate of rotavirus A and HAdV was highest among participants aged 3 to 6 years, whereas the detection rate of norovirus was highest among those aged 1 to 3 years. The monthly distribution peaks for the three enteric viruses varied significantly.

N-Chlorosuccinimide: A Versatile Reagent in Organic Synthesis

N-Chlorosuccinimide (NCS) is a five-membered N-containing heterocyclic molecule. This is a versatile reagent and is successfully employed for different types of reactions. Initially, this was employed for chlorination only but soon became an excellent reagent for many reactions, including halocyclizations, functional group transformations, formation of carbon-carbon bonds, etc. This review article covers representative applications of NCS for aliphatic and aromatic chlorination, chlorination of atoms other than carbon, oxidation, and other reactions.

Aminosulfonylation of Rhodium Carbene via Ylide Formation and 1,4-Sulfonyl Rearrangement.

We report here the use of pyridin-2-yl benzenesulfonates as sulfonylation reagents in a difunctionalization reaction based on oxy-pyridinium ylide chemistry, providing an effective protocol for the installation of both a sulfonyl group and a pyridone moiety into one molecule. Density functional theory (DFT) calculations disclose that the reaction process might proceed through sequential metal-bound ylide formation, keto-enol tautomerism, and the migratory rearrangement of the sulfonyl group.

Synthesis, Structures, and Reactivity of Organostannanides and Organogermanides of Copper(I).

Organogermane and organostannane compounds are valuable reagents in cross coupling reactions, and copper(I) germanide and stannanide complexes can provide convenient access to these compounds. This review presents the chemistry of copper(I) germanide and stannanide complexes, with a particular focus on systems at the frontier of organic and inorganic chemistry where structural characterisation of coordination complexes facilitates rationalisation of organic mechanisms. These species show both similarities to, and significant divergences from their lighter silanide congeners. For example, they are all viable sources of the relevant organotetranide anion, but in the cases of both germanium and tin, the tetranides can be accessed via direct deprotonation of the corresponding tetranes, a reaction unknown for silicon. Further divergences between copper(I) germanides and stannanides are highlighted; whilst both can be used in productive organic transformations to access organotetranes, catalytic reactions are only reported for germanium. The rather striking ability of triphenylstannanides to acts as sources of the phenyl anion are discussed; the mechanism of this reaction is still subject to discussion, but its absence in the chemistry of germanium and silicon is now well-rationalised. We conclude this review by considering potential research directions in the synthesis and exploitation of copper(I) germanides and stannanides.

Comparison of Different Organometallics Towards Electrophilic Aromatic 211At-Astatinations of Highly Reactive Tetrazines.

Organometallics can be used as precursors for electrophilic 211At-statinations. In this report, we compared the potential of aryl trimethylsilanes, -germanes, or -stannanes to be used as precursors to 211At-label highly reactive tetrazines. Tetrazines can be used for pretargeted radioligand therapies or be applied as synthons to radiolabel rapidly and orthogonally a broad set of precursors such as peptides, mAbs or nanomedicines. All precursors could successfully be synthesized and radiolabeled. The reactivity of organogermanium reagents ranged between those of respective organotin and organosilicon precursors. Moreover, organogermanium reagents proved promising for accessing more complex and polar tetrazine scaffolds. In contrast to organotin derivatives, the use of protecting groups could be avoided for organogermanium and -silicon precursors. The developed 211At-labeled tetrazines could be labeled in radiochemical conversions of 60-90%. Organogermanium and -silicon precursors were clearly advantaged as additional deprotection steps could avoided. Reported labeling procedures allow astatinations of highly reactive tetrazines to be used for pretargeted approaches or to applied as highly reactive synthons to label the next-generation of 211At-labeled radiopharmaceuticals.

Synthesis and Characterization of Extremely Bulky Aminopyridinate Ligands and a Series of Their Groups 1 and 2 Metal Complexes

High-yielding synthetic routes to five new extremely bulky aminopyridine pro-ligands were developed, viz. (C5H3N-6-Ar1)N(H)Ar2-2; Ar1 = Trip, Ar2 = TCHP (HAmPy1), Ar* (HAmPy2) or Ar† (HAmPy3); Ar1 = TCHP, Ar2 = Ar* (HAmPy4) or Ar† (HAmPy5) (Trip = 2,4,6-triisopropylphenyl, TCHP = 2,4,6-tricyclohexylphenyl, Ar* = C6H2(CHPh2)2Me-2,6,4, Ar† = C6H2(CHPh2)2Pri-2,6,4. Four of these were deprotonated with LiBun in diethyl ether to give lithium aminopyridinate complexes which were dimeric for the least bulky ligand, [{Li(AmPy1)}2] or monomeric for the bulkier aminopyridinates, i.e., in [Li(AmPy2−4)(OEt2)]. One aminopyridine was deprotonated with MeMgI to give monomeric [Mg(AmPy3)I(OEt2)2]. When treated with sodium or potassium mirrors or 5% w/w Na/NaCl, over-reduction occurred, leading to the alkali metal aminopyridinates, [M(AmPy3)(η6-toluene)] (M = Na or K) or [{Na(AmPy3)}∞]. An attempted reduction of [Mg(AmPy3)I(OEt2)2] with a dimagnesium(I) compound led only to partial loss of diethyl ether and the formation of [(AmPy3)Mg(μ-I)2Mg(AmPy3)(OEt2)]. All prepared complexes have potential as ligand transfer reagents in salt metathesis reactions with metal halide complexes.

Recent Progress in the Photocatalytic Synthesis of α‐Tertiary Primary Amines

Abstractα‐Tertiary primary amines (α‐TPAs) bearing a fully substituted carbon center adjacent to the N‐unsubstituted amino group (−NH2) exhibit unique biochemical and physicochemical activities. While due to the sterically congested structure and strong nucleophilic and alkaline natures of these primary amine compounds, their facile synthesis remains an inherent challenge. Traditional methods commonly rely on tedious N‐protection/deprotection operations and highly reactive organometallic reagents, thus leading to poor atom and step‐economy and limited functional group compatibility. Modern photoredox catalysis offers a robust tool to prepare such structurally unique and synthetically valuable amine architectures via a radical pathway under extremely mild conditions. In this review, the recent progress in photocatalytic synthesis of α‐TPAs is systematically reviewed, and the reaction scope, limitations, and mechanisms for the reactions are discussed.

Organoboron catalysis for direct amide/peptide bond formation.

Amides and peptides are ubiquitous functional groups found in several natural and artificial materials, and they are essential for the advancement of life and material sciences. In particular, their relevance in clinical medicine and drug discovery has increased in recent years. Dehydrative condensation of readily available carboxylic acids with amines is the most "direct" method for amide synthesis; however, this methodology generally requires a stoichiometric amount of condensation agent (coupling reagent). Catalytic direct dehydrative amidation has become an "ideal" methodology for synthesizing amides from the perspective of green chemistry, with water as the only byproduct in principle, high atom efficiency, environmentally friendly, energy saving, and safety. Conversely, organoboron compounds, such as boronic acids, which are widely used in various industries as coupling reagents for Suzuki-Miyaura cross-coupling reactions or pharmaceutical structures, are environmentally friendly molecules that have low toxicity and are easy to handle. Based on the chemical properties of organoboron compounds, they have potential Lewis acidity and the ability to form reversible covalent bonds with dehydration, making them attractive as catalysts. This review explores studies on the development of direct dehydrative amide/peptide bond formation reactions from carboxylic acids using organoboron catalysis, classifying them based on chemical bonding and catalysis over approximately 25 years, from the early developmental days to 2023.

Benzoyl cyanide, a general radical acylating reagent for photoredox-catalyzed benzylic site-selective acylation reactions

Benzoyl cyanide, a general radical acylating reagent for photoredox-catalyzed benzylic site-selective acylation reactions

Late-Stage Halogenation of Complex Substrates with Readily Available Halogenating Reagents.

ConspectusLate-stage halogenation, targeting specific positions in complex substrates, has gained significant attention due to its potential for diversifying and functionalizing complex molecules such as natural products and pharmaceutical intermediates. Utilizing readily available halogenating reagents, such as hydrogen halides (HX), N-halosuccinimides (NXS), and dichloroethane (DCE) reagents for late-stage halogenation shows great promise for expanding the toolbox of synthetic chemists. However, the reactivity of haleniums (X+, X = Cl, Br, I) can be significantly hindered by the presence of various functional groups such as hydroxyl, amine, amide, or carboxylic acid groups. The developed methods of late-stage halogenation often rely on specialized activating reagents and conditions. Recently, our group (among others) has put great efforts into addressing these challenges and unlocking the potential of these readily available HX, NXS, and DCE reagents in complex molecule halogenation. Developing new methodologies, catalyst systems, and reaction conditions further enhanced their utility, enabling the efficient and selective halogenation of intricate substrates.With the long-term goal of achieving selective halogenation of complex molecules, we summarize herein three complementary research topics in our group: (1) Efficient oxidative halogenations: Taking inspiration from naturally occurring enzyme-catalyzed oxidative halogenation reactions, we focused on developing cost-effective oxidative halogenation reactions. We found the combination of dimethyl sulfoxide (DMSO) and HX (X = Cl, Br, I) efficient for the oxidative halogenation of aromatic compounds and alkenes. Additionally, we developed electrochemical oxidative halogenation using DCE as a practical chlorinating reagent for chlorination of (hetero)arenes. (2) Halenium reagent activation: Direct electrophilic halogenation using halenium reagents is a reliable method for obtaining organohalides. However, compared to highly reactive reagents, the common and readily available NXS and dihalodimethylhydantoin (DXDMH) demonstrate relatively lower reactivity. Therefore, we focused on developing oxygen-centered Lewis base catalysts such as DMSO, 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) and nitromethane to activate NXS or DXDMH, enabling selective halogenation of bioactive substrates. (3) Halogenation of inert substrates: Some substrates, such as electron-poor arenes and pyridines, are inert toward electrophilic functionalization reactions. We devised several strategies to enhance the reactivity of these molecules. These strategies, characterized by mild reaction conditions, the ready availability and stability of catalysts and reagents, and excellent tolerance for various functional groups, have emerged as versatile protocols for the late-stage aromatic halogenation of drugs, natural products, and peptides. By harnessing the versatility and selectivity of these catalysts and methodologies, synthetic chemists can unlock new possibilities in the synthesis of halogenated compounds, paving the way for the development of novel functional materials and biologically active molecules.

Phosphonium SF5 - Salts Derived from Sulfur Hexafluoride as Deoxyfluorination Reagents.

Sulfur based deoxyfluorination reagents are usually derived from the corrosive gas SF4. Herein, we report the synthesis and properties of an easily accessible phosphonium salt [(tmg)3PF]+SF5 - (1) which was obtained from the reaction of sulfur hexafluoride (SF6) with tris(tetramethylguanidinyl)phosphine. The performance of this crystalline SF5 - salt as a reagent in deoxyfluorination reactions was investigated together with a second SF5 - salt [(R1)3PF]+SF5 - (2) containing bulky substituents (R1=1,3-di-tert-butylimidazolidin-2-ylidenamino). Both reagents proved to be effective for the deoxyfluorination of various functional groups including alcohols, anhydrides, and amides.

Generation and Application of Sulfur Ylides in Light‐Mediated Transformations

Sulfur ylides are essential reagents in various organic reactions like epoxidation and cyclopropanation. While traditionally employed in ionic chemistry, recent advancements in visible‐light‐driven photocatalysis reveal their potential as sources of radicals or free carbenes. The photochemical or photocatalytic generation of reactive intermediates using sulfur ylides expands the utility of these reagents in modern organic synthesis, offering sustainable solutions to emerging challenges. Despite early demonstrations in the 1960s, the past years have witnessed a surge in photochemical methods utilizing sulfur ylides as precursors. The use of redox‐active photocatalysts has facilitated numerous radical reactions. This review consolidates key findings in sulfur ylide chemistry, particularly focusing on photo‐mediated reactions, to stimulate further research interest in this dynamic field.

Structural design of cellulose-hyperbranched double-network for enhanced intramolecular diffusion kinetics of heavy metal ion capture processes

Extracting cellulose from agricultural residues and converting it into environmentally friendly adsorbents to solve the heavy metal contamination problem of groundwater and farmland is an effective strategy to achieve high-value utilization of agricultural residues. Herein, we propose a streamlined crosslinking strategy to fabricate a cellulose-based amphoteric hyperbranched adsorbent (MAHPA) in a controlled manner. The strategy involves synthesizing the amphoteric hyperbranched functional reagent first and then crosslinking it with microcrystalline cellulose (MCC). This approach simplifies the complexity of the multi-component cross-linking system, resulting in a conversion rate of reaction reagents exceeding 99 %. MAHPA, with a three-dimensional hyperbranched structure (degree of branching: 0.77), exhibits a high swelling rate (247.62 %) and high densities of carboxyl (7.05 mmol·g−1) and amino (8.27 mmol·g−1) groups. Moreover, the cellulose-hyperbranched double-network structure of MAHPA greatly enhances the intramolecular diffusion kinetics of heavy metal ions on MAHPA, enabling it to complete the removal of low concentrations of Cr(VI), As(V), Pb(II), and Cd(II) within 20 min. Interestingly, MAHPA demonstrates excellent synchronous capture performance for Cr(VI), As(V), Pb(II), and Cd(II) in groundwater at a velocity of 1.60 × 10−2 m·s−1. Meanwhile, applying MAHPA can realize the safe utilization of Cd-As contaminated soil. This work offers a general strategy for the structural design of cellulose-based hyperbranched adsorbent holding great promise as heavy metal contaminated groundwater and soil remediation field.

Proton Transport Scenarios in Sulfuric Acid Explored via Ab Initio Molecular Dynamics Simulations.

Sulfuric acid (H2SO4), a highly reactive reagent containing intrinsic protonic charge carriers, has been studied via ab initio molecular dynamics simulations. Specifically, we explore the solvation shell structure of the protonic defects, H1SO4- and H3SO4+, as well as the underlying proton transport mechanisms in both the neat and hydrated H2SO4 solutions. Our findings reveal a significant contraction of the dynamic hydrogen-bonded network around the protonic defects, which resembles features seen in water. The simulations provide estimates of the structural relaxation time scales for proton release from both the covalent O-H bonds (∼23 ps) and the hydrogen bonds (∼0.4 ps). In contrast to water, our analysis of the proton transfer scenarios in sulfuric acid reveals correlated events mediated by the formation of longer (up to four) hydrogen-bonded Grotthuss chains.

Formate Salt as a Bifunctional Reagent for Hydroxylation and Carbonylation Reactions Under Photochemically Driven Nickel Catalysis.

In this study, we disclose for the first time that formate salt can be used as a bifunctional reagent for the synthesis of phenol derivatives and as a CO source for carbonylative cross-coupling processes using the COware gas reactor under activation free conditions. Key to this success is the in-situ synthesis of aryl formate via an unprecedented nickel/organophotocatalyst system under blue LED irradiation. This developed system demonstrated high applicability to various aryl iodide substrates for synthesizing phenol derivatives. Moreover, the generated CO could be utilized in a range of carbonylative C-heteroatom and C-C processes. Notably, commercially available H13COONa salt can serve as a bifunctional reagent for both synthesizing phenols and generating 13CO.

Air-Stable Boranes and Borinanes Encapsulated in Organogels for Anionic Ring-Opening (Co)Polymerization.

Organoborane reagents play a pivotal role as Lewis acids in acid-base pairs used in anionic polymerization and in other reactions; yet their high sensitivity to oxygen and moisture necessitates effective stabilization to prevent their oxidation and thus maintain their catalytic activity. In this study, we present novel encapsulation methods employing a cost-effective hexatriacontane (C36H74, C36) organogel to stabilize sensitive organoborane reagents, including triethyl borane (TEB) and a borinane-based ammonium salt (B3NBr). These organoboranes encapsulated in stable, self-standing organogel blocks enable their safe handling in open laboratory environments without the need for a glovebox. Upon heating such borane-containing organogel blocks organoboranes could be freed from the organogel and used to mediate both the homopolymerization of propylene oxide (PO) and the copolymerization of PO with CO2. Furthermore, efficient recovery of the C36 gelator from polymerization mixtures is achieved, with mass recovery ranging from 70 % to 90 %. This encapsulation method offers a practical and efficient solution for stabilizing, storing, and handling highly reactive organoborane reagents, thereby broadening their applicability and utilization in various chemical transformations.

Current and Potential Applications of Vibrational Spectroscopy as a Tool in Black Soldier Fly Production and the Circular Economy

Edible insects are characterized by their low environmental footprint compared with traditional sources of animal and plant proteins. This is due to the high feed conversion efficiency of edible insects. The black soldier fly (Hermetia illucens) larvae (BSFL) are one of the preferred candidates to be used as alternative sources of protein, due to their ability to add value to a wide range of organic and food waste streams. The ability of BSFL to convert organic matter into protein has resulted in a viable and sustainable ingredient to be utilized in animal feed or human food. BSFL have also been considered as key components of the circular economy due to their intrinsic characteristics and properties. The evaluation of the chemical composition, nutritive value, and functional properties of BSFL have been achieved by the utilization of traditional methods of analysis, although most of these procedures do not agree with the requirements of a circular economy due to their intrinsic characteristics (e.g., destructive, energy use, highly reactive reagents, etc.). Therefore, green analytical technologies have been evaluated, of which infrared (IR) spectroscopy has several advantages. This article reviews current and potential applications of IR spectroscopy combined with chemometrics to analyze the proximate composition, functional characteristics, and traceability of BSFL and frass samples.

Simple Framework for Simultaneous Analysis of Both Electrodes in Stoichiometric Lithium-Sulfur Batteries.

A battery is composed of two electrodes that depend on and interact with each other. However, galvanostatic charging-discharging measurement, the most widely used method for battery evaluation, cannot simultaneously reflect performance metrics [capacity, Coulombic efficiency (CE), and cycling stability] of both electrodes because the result is generally governed by the lower-capacity electrode of the cell, namely the limiting reagent of the battery reaction. In studying stoichiometric Li-S cells operating under application-relevant high-mass-loading and lean-electrolyte conditions, we take advantage of the two-stage discharging behavior of sulfur to construct a simple framework that allows us to analyze both electrodes simultaneously. The cell capacity and its decay are anode performance descriptors, whereas the first plateau capacity and cell CE are cathode performance descriptors. Our analysis within this frame identifies Li stripping/plating and polysulfide shuttling to be the limiting factors for the cycling performance of the stoichiometric Li-S cell. Using our newly developed framework, we examine various previously reported strategies to mitigate these bottleneck problems and find modifying the separator with a reduced graphene oxide layer to be an effective means, which improves the capacity retention rate of the cell to 99.7% per cycle.

Biopolymer-enhanced delivery of reactive sulfide reagents for in-situ mercury remediation of heterogeneous contaminated soils

Mercury pollution from natural and anthropogenic sources demands effective remediation. This study focuses on optimizing a chemical stabilization approach using sulfur-containing compounds to create stable mercury sulfide (HgS) and immobilize elemental mercury in polluted soils. We propose using xanthan gum biopolymer to enhance the in-situ delivery of sulfide microparticles, overcoming soil heterogeneities due to its non-Newtonian behavior. Stability tests indicated that increased biopolymer concentration enhances particle stability due to the viscous and shear-thinning behavior of the polymer solutions. Various combinations (12 solutions) of xanthan polymer, pyrite microparticles, and sulfide-containing reagents were tested in batch experiments. Pyrite microparticles slightly reduced the xanthan solution's viscosity while retaining its non-Newtonian character. All solutions effectively transformed liquid mercury droplets into cinnabar, demonstrating successful mercury stabilization. Notably, solutions containing PIAX and SIPX, xanthate organosulfur compounds, significantly reduced the dissolved concentration of elemental mercury. Column experiments demonstrated xanthan gum's superior performance for in-situ injection of pyrite microparticles and sulfide mixtures into the soil compared to conventional water injection. At a polymer concentration of 4 g/L, a stable displacement front and an 88 % recovery of the initially injected particle-suspension density were achieved. The combined effects of xanthate's floating behavior and xanthan gum's shear-thinning nature substantially enhanced the delivery of pyrite microparticles in porous media for soil mercury remediation. This combination reduced the aqueous elemental mercury concentration in artificially polluted sand by up to 97 %, particularly with the xanthate organosulfur compound, PIAX. Xanthate has a higher potential to react with elemental mercury to form cinnabar compared to sodium thiosulfate. Additionally, the pyrite microparticles, rendered hydrophobic in xanthate solutions, integrated into the mercury droplets, forming a black paste. This study introduces a promising approach for efficient elemental mercury stabilization in contaminated soils by integrating biopolymers, reactive soluble compounds, and pyrite microparticles for sustainable decontamination.

Stereodivergent Synthesis of Pyridyl Cyclopropanes via Enzymatic Activation of Pyridotriazoles.

Hemoproteins have recently emerged as powerful biocatalysts for new-to-nature carbene transfer reactions. Despite this progress, these strategies have remained largely limited to diazo-based carbene precursor reagents. Here, we report the development of a biocatalytic strategy for the stereoselective construction of pyridine-functionalized cyclopropanes via the hemoprotein-mediated activation of pyridotriazoles (PyTz) as stable and readily accessible carbene sources. This method enables the asymmetric cyclopropanation of a variety of olefins, including electron-rich and electrodeficient ones, with high activity, high stereoselectivity, and enantiodivergent selectivity, providing access to mono- and diarylcyclopropanes that incorporate a pyridine moiety and thus two structural motifs of high value in medicinal chemistry. Mechanistic studies reveal a multifaceted role of 7-halogen substitution in the pyridotriazole reagent toward favoring multiple catalytic steps in the transformation. This work provides the first example of asymmetric olefin cyclopropanation with pyridotriazoles, paving the way to the exploitation of these attractive and versatile reagents for enzyme-catalyzed carbene-mediated reactions.