Source Of Reagents Research Articles

Iodine-Catalyzed [5 + 1] Carbonylation of 2-Alkenyl/Pyrrolylanilines with CS2 as the Carbonylating Reagent.

Novel metal-free iodine (I2)-catalyzed [5 + 1] carbonylation of 2-alkenyl/pyrrolylanilines with carbon disulfide (CS2) as the carbonylating reagent has been developed. This innovative method allows for the synthesis of valuable derivatives such as 4-aryl-2-quinolinones and pyrrolyl-fused quinoxalinones. Notably, this work represents the first instance where CS2 has been utilized as a carbonylating reagent source. The protocol demonstrates the utilization of various substrates, leading to diverse reactions that afford excellent yields under mild conditions. The method also shows good compatibility with functional groups present in the substrates, further enhancing its synthetic utility. Importantly, the developed reaction exhibits scalability, enabling gram-scale synthesis, and shows promise for the synthesis of druglike molecules. In this catalytic system, CS2 serves as the carbonyl source, while dimethyl sulfoxide plays multiple roles, including acting as an oxidant and a solvent. Mechanistic studies have been conducted to elucidate the underlying processes, with the formation of quinolone-2-thiones identified as crucial intermediates, facilitating the carbonylation annulation process.

In situ synthesis BiOBr/Bi-TDC composite with rich oxygen vacancy to remove rhodamine B and tetracycline under ultrasound and illumination

A series of 3D hierarchical microsphere heterojunction composites combining BiOBr and Bi-MOF (Bi-TDC) supported by 2,5-thiophene dicarboxylate acid (H2TDC) was fabricated by one-step solvothermal method. Hexadecyl trimethyl bromide (CTAB) is used as the structure guide reagent and Br source to design BiOBr/Bi-TDC composites and enhance catalytic activity. The ultrasound-assisted photocatalysis effect of BiOBr/Bi-TDC for RhB and TC can reach 99.8 % and 96.1 % in 30 min, respectively. Further, the influence factor of photocatalytic degradation TC solution were explored, including pH, initial pollutant concentration, catalyst dosage and different proportions of BiOBr and Bi-TDC. The excellent catalytic activity can be attributed to the construction of heterogeneous interfaces and rich oxygen vacancies (OVs), which improve the low redox potentials and facilitate the separation of photogenerated electron-hole pairs. Radical trapping experiment is made and shown •O2− and h+ are the most active species for the photodegradation process. The EPR characteristic is also used to explore free radicals when exposed to the visible light illumination.

Revealing the Mechanism of Alcohol Dehydroxylation and C-C Bond Formation through Concerted Catalysis by Ir/Cu Bimetallic Complexes.

The density functional theory (DFT) was employed to theoretically investigate the reaction mechanism of alcohol deoxygenation/trifluoromethylation. The substrate alcohol (R1) forms a complex (INT3) by binding with benzoxazole salts (NHCs). Under the influence of the photocatalyst ([IrIII]*) and quinuclidine, the C-H bond in INT3 is activated through either electron transfer-proton transfer (ETPT) or hydrogen atom transfer (HAT) mechanisms, resulting in the cleavage of C-O bonds and generation of deoxyalkyl radicals. The distribution of high-valent and low-valent states in the catalytic cycle of [Ir]-complexes is governed by the redox potential mechanism. Investigation was conducted on the source of hydrogen atom transfer reagents in the HAT reaction process under both optimal and nonoptimal conditions. The results demonstrate distinct reactivity among various radicals involved in the Cu-mediated radical capture process. Further investigations into INT3 activation modes, cycling facilitated by [Ir]-complexes, and understanding the role played by [Cu]-complexes in this reaction system provide a valuable theoretical foundation for comprehending and enhancing Ir/Cu bimetallic cooperative catalysis in alcohol deoxygenation/trifluoromethylation reactions. This provides anticipated theoretical support for future designs of more efficient and rational alcohol deoxygenation reactions.

BF3-Promoted Ring Expansion of Iminylphosphiranes and Acylphosphiranes for Divergent Access to 1,2-Azaphospholidines and 1,2-Dihydrophosphetes.

Ring expansion of strained small rings provides an efficient method for the synthesis of various high-value carbocycles and heterocycles. Here we report BF3·Et2O as both an activating reagent and fluorine source, enabling ring expansion of phosphirane and P-F bond formation. Treatment of 1-iminylphosphirane complexes with BF3·Et2O resulted in 1,2-azaphospholidines, while the reaction of 1-acylphosphirane complexes with BF3·Et2O afforded 1,2-dihydrophosphetes. The reaction path was tuned by the nucleophilicity of the N and O atoms toward the intermediate phosphenium cation.

Treatment of Spray Paint Wastewater by a Coupled Electro-Fenton and SBR Technology

Spray painting wastewater is industrial wastewater created during the painting process; its composition is complicated, comprising a significant number of difficult biodegradable organic matter; nevertheless, the existing technology is not optimal, and the process cannot reach the desired criteria. The water quality of the entry has a higher demand for investment and occupying a vast land. High maintenance expenses, high water quality after treatment, and other issues exist. In this study, the oily spray paint wastewater was treated using an electrochemical and Fenton process, which has a high oxidation capacity, a fast oxidation rate, and a wide application of the characteristics of the Electro-Fenton process used in the pretreatment of spray paint wastewater. This study focuses on the electrochemical optimization and improvement of the Fenton technique, and it employs Fe2+ and H2O2 generated by the electrochemical approach as a continuous source of Fenton reagent. Simultaneously, electrode-related oxidation may destroy organic matter, effectively reducing the concentration of organic matter in spray paint wastewater, and when paired with the traditional Sequencing Batch Reactor Activated Sludge Process (SBR) operation treatment mode, offers a comprehensive process idea. While improving the efficiency and quality of spray paint wastewater treatment, the cost should be kept as low as feasible in order to provide effective reference schemes for spray paint wastewater treatment, allowing for future study.

Light-Activated BF3·Et2O-Promoted Generation of Singlet Oxygen and Cascade Reaction of Unsaturated Amides.

Herein, BF3·Et2O-promoted O-insertion/spirocyclization/fluorination/ring-expansion of unsaturated amides to synthesis of spiro[benzo[b]-[1,4]dioxepine-3,5'-oxazole] skeletons in the presence of natural light and O2 (3Σg-) was reported. Air was the oxygen source of the 1O2-generation and O-insertion reaction under metal-free and mild conditions. BF3·Et2O played multiple roles, such as Lewis acid, activating reagent, and fluorine source in the reported cascade. A mechanism involving 1O2 generation/activation of double bond/O-insertion/spirocyclization/fluorination/ring expansion was supposed.

Preparation of inexpensive S-doped porous carbons for high-performance supercapacitors

Low-cost sulfur-doped porous carbons were prepared through hard template method by using inexpensive colloidal SiO2 nanoparticles as template, glucose as carbon source, H2SO4 as pre‑carbonized reagent and sulfur source. The effects of H2SO4 and carbonization temperature on the microscopic morphology, the pore structure and the specific surface area of porous carbons were explored through multiple characterization methods. The capacitive performance of porous carbons was investigated by multiple electrochemical methods. It was found that the pore structure, specific surface area and the content of sulfur element of carbon are highly dependent on the carbonization temperature. The sulfur-doped porous carbon SPC-900 has much larger surface area and larger pore volume, and thus much better capacitive performance than un-doped PC-900, indicating that H2SO4 can increase the surface area and the pore volume during the preparation process. SPC-900 offers the advantages of lower cost, larger pore size, higher pore volume, better capacitive performance and better rate performance compared to expensive mesoporous carbon CMK-3. In the three-electrode system, the specific capacitance of SPC-900 can reach 363 F g−1, whereas that of PC-900 is only 164 F g−1 at a current density of 0.5 A g−1. The double layer capacitance (EDLC) and pseudocapacitance can both be increased by the sulfur element, according to the capacitive contribution study. Additionally, the SPC-900 can maintain its initial specific capacitance of 98.1 % for 10,000 cycles at a current density of 0.5 A g−1, demonstrating both its high cycling performance and potential for practical applications.

Development and characterization of a hemolysis inhibition assay to determine functionality of anti-Streptolysin O antibodies in human sera

The high burden of disease and the long-lasting sequelae following Streptococcus pyogenes (Strep A) infections make the development of an effective vaccine a global health priority. Streptolysin O (SLO), is a key toxin in the complex pathogenesis of Strep A infection. Antibodies are elicited against SLO after natural exposure and represent a key target for vaccine-induced immunity. Here we present the setup and characterization of a hemolysis assay to measure functionality of anti-SLO antibodies in human sera. Assay specificity, precision, linearity, reproducibility, and repeatability were determined. The assay was demonstrated to be highly sensitive, specific, reproducible, linear and performed well in assessing functionality of anti-SLO antibodies induced by exposed individuals. Moreover, different sources of critical reagents, in particular red- blood cells, have been compared and had minimal impact on assay performance. The assay presented here has throughput suitable for evaluating sera in vaccine clinical trials and sero-epidemiological studies to gain further insights into the functionality of infection- and vaccine-induced antibodies.

Разработка нового нанобиотехнологического метода и его применение для дифференциальной диагностики опухолей придаточного аппарата глаза

Aim: to develop a new nanobiotechnology method for the differential diagnosis of ocular adnexal tumors. Patients and Methods: 192 eyelid or conjunctival tumor samples from 192 patients were examined. Controls were healthy tissue samples from the same eye. To register and obtain significant differences in the generation of biogenic silver nanoparticles in situ, the key parameters of the reaction of the reduction of silver cations were selected and optimized. To generate de novo biogenic silver nanoparticles, tissue samples were placed in a sterile solution of a cation source in aseptic conditions. Nanoparticles were generated in situ using a sterile solution of Tollens' reagent (Ag(HN3)2NO3). Results: the optimal parameters of a new nanobiotechnology method were established to conduct the reduction reaction to generate biogenic silver nanoparticles. The required concentration of Tollens' reagent (source of cations) was 63 μg/ml. The wavelength used to observe the de novo generation of biogenic silver nanoparticles (λ) was 410 nm. Obtaining the most significant changes in the optical density of the reaction mixture with biogenic nanoparticles required 10 to 20 min, although the first changes were documented starting from the 5th minute of the reduction reaction. Benign and malignant tumors are characterized by different metabolic activities, i.e., benign eyelid and conjunctival tumors reduce cations more slowly than malignant tumors. The parameters of reducibility of benign ocular adnexal tumors did not significantly differ depending on tumor location and type. Among the malignant conjunctival tumors, melanoma is characterized by the highest reducibility p<0.05). Among the malignant eyelid tumors, no significant differences were found for different tumor types. Conclusions: this novel nanobiotechnology method provides a differential diagnosis of benign and malignant ocular adnexal tumors. The practical relevance of this method lies in differentiating benign and malignant tumors to schedule management strategies and surgical interventions. KEYWORDS: tumor, eyelids, conjunctiva, silver nanoparticles, biogenic synthesis, express diagnostics, ocular oncology. FOR CITATION: Saakyan S.V., Skladnev D.A., Alekseeva A.P., Beznos O.V., Sorokin V.V. Development of a new nanobiotechnology method for the differential diagnosis of ocular adnexal tumors. Russian Journal of Clinical Ophthalmology. 2024;24(1):25–29 (in Russ.). DOI: 10.32364/2311-7729-2024-24-1-5.

Nanobody-Mediated Dualsteric Engagement of the Angiotensin Receptor Broadens Biased Ligand Pharmacology.

Dualsteric G protein-coupled receptor (GPCR) ligands are a class of bitopic ligands that consist of an orthosteric pharmacophore, which binds to the pocket occupied by the receptor's endogenous agonist, and an allosteric pharmacophore, which binds to a distinct site. These ligands have the potential to display characteristics of both orthosteric and allosteric ligands. To explore the signaling profiles that dualsteric ligands of the angiotensin II type 1 receptor (AT1R) can access, we ligated a 6e epitope tag-specific nanobody (single-domain antibody fragment) to angiotensin II (AngII) and analogs that show preferential allosteric coupling to Gq (TRV055, TRV056) or β-arrestin (TRV027). While the nanobody itself acts as a probe-specific neutral or negative allosteric ligand of N-terminally 6e-tagged AT1R, nanobody conjugation to orthosteric ligands had varying effects on Gq dissociation and β-arrestin plasma membrane recruitment. The potency of certain AngII analogs was enhanced up to 100-fold, and some conjugates behaved as partial agonists, with up to a 5-fold decrease in maximal efficacy. Nanobody conjugation also biased the signaling of TRV055 and TRV056 toward Gq, suggesting that Gq bias at AT1R can be modulated through molecular mechanisms distinct from those previously elucidated. Both competition radioligand binding experiments and functional assays demonstrated that orthosteric antagonists (angiotensin receptor blockers) act as non-competitive inhibitors of all these nanobody-peptide conjugates. This proof-of-principle study illustrates the array of pharmacological patterns that can be achieved by incorporating neutral or negative allosteric pharmacophores into dualsteric ligands. Nanobodies directed toward linear epitopes could provide a rich source of allosteric reagents for this purpose. SIGNIFICANCE STATEMENT: Here we engineer bitopic (dualsteric) ligands for epitope-tagged angiotensin II type 1 receptor by conjugating angiotensin II or its biased analogs to an epitope-specific nanobody (antibody fragment). Our data demonstrate that nanobody-mediated interactions with the receptor N-terminus endow angiotensin analogs with properties of allosteric modulators and provide a novel mechanism to increase the potency, modulate the maximal effect, or alter the bias of ligands.

Development of novel gradient RP-HPLC method for separation of dapagliflozin and its process-related impurities: insight into stability profile and degradation pathway, identification of degradants using LCMS

BackgroundIn the dapagliflozin (DPF) synthesis, 5-Bromo-2-chlorobenzoic acid (5-BC impurity) and 4-Bromo-1-chloro-2-(4-ethoxybenzyl) benzene (4-BC impurity) are used as starting and reagent sources, respectively. The presence of 5-BC and 4-BC impurities in DPF could potentially affect the effectiveness of the final DPF product. The purpose of this investigation was to develop a stability indicating HPLC methodology for the separation of DPF, its process-related impurities and degradants. The method of analysis was developed on Xbridge Phenyl C18 column of dimensions, 250 × 4.6 mm, 5 μm with gradient elution using mobile phase made up of 0.05% aqueous trifluoroacetic acid and acetonitrile (AcN).ResultsThe method proposed indicates a good linearity (R2 = 0.9996 and 0.9993), good system precision (RSD ≤ 2%), good method precision (RSD ≤ 2%), accuracy (50–150%), LOD (0.000053 ppm and 0.0000165 ppm) and LOQ (0.00016 ppm and 0.00005 ppm) for 4-BC impurity and 5-BC impurity, respectively. LC–MS was used to detect and characterise degradants that were obtained in acid and base condition were identified and characterised. A comparison of the fragmentation pattern of the [M + H] + ions of DPF and its degradation products revealed the most likely processes for the generation of degradation products.ConclusionDPF sample quality can be evaluated using the suggested method for the presence of 4-BC impurity, 5-BC impurity and 2-(3-(4-ethoxy benzyl)-4-chloro phenyl)-tetrahydro-6-(hydroxy methyl)-2H-pyran-3,4,5-triol.

Reactive natural deep eutectic solvents increase selectivity and efficiency of lipase catalyzed esterification of carbohydrate polyols

A novel approach for the enzymatic esterification of carbohydrate polyols with fatty acids was investigated, with reactive natural deep eutectic solvents (R-NADES) as reaction medium and source of reagents. Three binary hydrophilic R-NADES consisting of choline chloride (ChCl) as hydrogen bond acceptor (HBA) and sugar alcohols (D-sorbitol, xylitol, D-arabitol) as hydrogen bond donors (HBD), were prepared and characterized. The carbohydrate polyol-based R-NADES were durable viscous fluids between 40 and 80⁰C, the common temperature range for an enzymatic reaction. The commercially accessible lipase B from Candida antarctica immobilized on acrylic resins (LAR) showed significant esterification activity and exceptional thermal stability in all three tested R-NADES and successfully catalyzed the synthesis of polyol esters. Box Behnken factorial design with three levels-three variables was used for optimizing the reaction conditions. The preparative esterification of D-arabitol with lauric acid (LA) at predicted optimal values for enzyme load, (i.e., 800 U/gram D-arabitol), temperature (70 °C) and LA/D-arabitol molar ratio of 1), attained 80 mol% LA conversion after 24 h reaction time. Structural analysis based on mass, infrared and nuclear magnetic resonance spectroscopy demonstrated that the reaction product is solely the diester 1,5-dilauryl-D-arabitol (1,5-DLDA). The 1,5-DLDA product, with an NMR-purity above 99.9%, was isolated in 95% yield. Under similar conditions, 1,5-dilauryl-xylitol (1,5-DLX) and 1,6-dilauryl-D-sorbitol (1,6-DLDS) were obtained, at a LA conversion of 56 mol% and 62 mol%, respectively. A combination of docking and molecular dynamics simulations allowed to rationalize the structural stability of the lipase B from Candida antarctica (CalB) active site in R-NADES, as well as the selectivity of the catalyzed esterification.

RECYCLING OF SOLID RESIDUE OF PYROLYSIS OF CAR TIRES

Link for citation: Bukharkina T.V., Verzhichinskaya S.V., Tarkhanova I.G., Konovalov A.V. Recycling of solid residue of pyrolysis of car tires. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 8, рр. 79-90. In Rus. The relevance. Tire recycling contributes to the environmental situation due to the cost-effective disposal of large volumes of tires out of service, in addition, it is an opportunity to obtain valuable chemical products without using natural resources as the main sources of initial reagents. The main aim of the research is to identify and propose directions for processing car tires and the solid residue of their pyrolysis, depending on their type and quality. Objects: automobile tires of domestic and foreign production; pyrolysis products and their subsequent refinement of various car tires. Methods: technical analysis of solid carbon-containing materials – Eschka method, iodometry for determining the iodine number, determination of moisture and pH of an aqueous suspension, ash content, volatile matter, light transmission coefficient of a toluene extract. Results. It was revealed that the solid pyrolysis residue studied in the work with the obtained indicators of its quality can be used as a filler in the rubber mixture or as a sorbent for heavy oil products, and a scheme was developed that reflects the ways of processing the solid pyrolysis residue obtained as a result of the disposal of passenger cars. and truck tires of various domestic and foreign manufacturers. The result of the work, in particular, the dependence of the direction of processing the solid residue of the pyrolysis of car tires from various manufacturers on its quality indicators, can serve as a theoretical basis for developing a unified program for recycling car tires in order to preserve and improve the environmental situation in various regions.

The Tungsten-Promoted Synthesis of Piperidyl-Modified erythro-Methylphenidate Derivatives.

Due to its efficacy as a dopamine receptor agonist, methylphenidate (MPH) is of interest as a potential therapeutic for cocaine addiction. While numerous derivatives of MPH have been investigated for their potential medicinal value, functionalization of the piperidine ring has not been explored. The pyridine borane ligand in WTp(NO)(PMe3)(η2-pyBH3) is dearomatized by the metal and can be elaborated to the analogous η2-mesylpyridinium complex. Installing a methyl phenylacetate moiety at the C2' position via a Reformatsky reaction followed by a tandem protonation/nucleophilic addition sequence results in a library of erythro MPH analogues functionalized at the piperidyl C5' position. The functional group is added chemoselectively to C5', cis to the methyl phenylacetate. Repeating this procedure with an enantioenriched source of the tungsten reagent results in enantioenriched MPH derivatives. All identities of the newly reported compounds are supported by comprehensive 2D NMR and HRMS data or crystallographic data.

Synthesis of aza-S(VI) motifs

Sulfoximines and sulfonimidamides are of interest as design options for medicinal chemists. This article describes the development of methods for the synthesis of sulfoximines by metal-free NH-transfer to sulfoxides, and NH/O transfer to sulfides, using convenient sources of ammonia and hypervalent iodine reagents. Similarly, sulfonimidamides are prepared from sulfenamides. Methods for the preparation of enantioenriched sulfonimidoyl fluorides are also described, as are their stereospecific reactions with amines and Grignard reagents. This work was presented at the 29th International Symposium on the Organic Chemistry of Sulfur (Guelph, July 2022).

Turning rice husks to a valuable boron and nitrogen co-doped porous C/SiOx composite for high performance lithium-ion battery anodes

For the exploitation of green biomass waste, boron (B) and nitrogen (N) co-doped porous C/SiOx composites ([email protected]/SiOx) have been successfully synthesized applying rice husks (RHs) as both C and Si sources and NH4HB4O7 as the porogen reagent and heteroatom source via a one-step calcination route. The volume fluctuation of SiOx can be effectively relieved and the electronic conductivity can be substantially enhanced with the homogeneous distribution of SiOx particles in the B, N co-doped porous C matrix. Specially, B, N co-doping effectively reduces the transmission barrier of Li+ in C skeleton of C/SiOx. The unique porous architecture, large specific surface area and B, N co-doping endow [email protected]/SiOx with the large reversible capacity, exceptional rate property and superior cycling stability. As lithium-ion batteries (LIBs) anodes, the optimized [email protected]/SiOx exhibits the cycling capacity of 1165 mAh/g at 100 mA/g and ameliorated initial coulombic efficiency (CE) of 74.3%. Even at 1.0 A/g, a stable cycling capacity of 650 mAh/g still can be obtained after 1200 cycles. This research offers a potential, relatively effective, cheap and environmental design of heteroatom doped biomass materials with enhanced Li+ storage performance.

Formalin-Fixed Paraffin-Embedded (FFPE) samples are not a beneficial replacement for frozen tissues in fetal membrane microbiota research

Formalin-Fixed Paraffin-Embedded (FFPE) tissues are routinely collected, archived, and used for clinical diagnosis, including maternal and neonatal health. Applying FFPE samples to microbiota research would be beneficial to reduce preparation, storage and costs associated with limited available frozen samples. This research aims to understand if FFPE fetal membrane samples are comparable to frozen tissues, which are the current gold standard for DNA microbiota analysis. Extracted DNA from nine matched paired patients were sequenced by Illumina sequencing of the V4 16S rRNA gene region. This included duplicate frozen amnion and chorion fetal membrane rolls or FFPE combined amniochorionic samples. Negative controls of surrounding wax blocks and DNA extraction reagents were processed alongside samples using identical methods. DNA quality and quantity was assessed by NanoDrop, agarose gel electrophoresis and Bioanalyzer. Decontam and SourceTracker were integrated into microbiota analysis to identify the presence of contaminating sources. The bacterial profile and nine genera differed between FFPE and frozen fetal membranes. There were no differences in bacterial profiles between FFPE samples and corresponding wax negative controls, with 49% of bacteria in FFPE fetal membrane samples matched to the source origin of paraffin wax, and 40% originating from DNA extraction reagent sources. FFPE samples displayed high fragmentation and low quantity of extracted DNA compared to frozen samples. The microbiota of FFPE fetal membrane samples is influenced by processing methods, with the inability to differentiate between the microbiota of the tissue sample and the surrounding wax block. Illumina sequencing results of FFPE and frozen fetal membrane samples should not be compared using the methods employed here. Variation could be influenced by limitations including storage time, DNA extraction and purification methods. To utilise FFPE fetal membrane samples in microbiota research then contamination prevention and detection methods must be included into optimised and standardised protocols, with recommendations presented here.

Solar assisted green photocatalysis for deducing carbamate insecticide from agriculture stream into water reclaiming opportunity

ABSTRACT ‘Ultraviolet’ and ‘Solar’ wastewater treatment units are used augmented with nanocrystals of magnetite, Fe2O3, which were previously synthesised via a cost-efficient co-perception route. The nanocrystals produced were used as a Fenton reagent source for the oxidising carbamate pesticide in aqueous solution through a combination of natural abundant solar radiation as well as artificial UV source. System parameters were examined and the optimal operating conditions were investigated to maximise the system yield. The objective optimisation was attained using a Box-Behnken factoring design (BBD) based on Response Surface Methodology, RSM. A mathematical model was developed and the maximal removal efficiency reached to 84.1% within 15 min of reaction time. Furthermore, the chemical oxygen demand was then investigated and it was oxidised and deduced to 57%. Analysis of the experimental data revealed that a second-order reaction model is best described the reaction kinetics. The calculated thermodynamic parameters suggested that the non-spontaneous nature of oxidation at high temperature was corroborated by positive Gibbs free energy change ∆G• and negative entropy, ∆S• values. Also, the negative values of enthalpy, ∆H•, indicated that the reaction was exothermic. The low activation energy barrier (−35.85 kJ/mol) indicated that the reaction proceeds at a low energy level.

Ru(III)-catalyzed construction of variously substituted quinolines from 2-aminoaromatic aldehydes (ketones) and isoxazoles: Isoxazoles as cyclization reagent and cyano sources

A Ru(Ⅲ)-catalyzed annulation reaction of 2-aminoaromatic aldehydes (ketones) and isoxazoles to afford diverse 3-cyanoquinolines has been developed. Notably, isoxazole acted as a cyclization reagent and nontoxic cyano source via N-O bond cleavage and fragmentation. Variously substituted (especially 6- or 7-substituted) quinolines could be easily afforded. This procedure features wide functional group compatibility, efficiency and avoiding toxic cyano source. Meanwhile, this protocol could be successfully applied to scale-up synthesis. Further chemical transformations of 3-cyanoquinoline could give some valuable skeletons, demonstrating its potential in synthetic application

Alkali halides as nucleophilic reagent sources for N-directed palladium-catalysed ortho-C-H halogenation of s-tetrazines and other heteroaromatics.

A general palladium-catalysed selective C-H halogenation reaction is reported, which was successfully achieved for a large variety of functionalized aromatic rings incorporating diverse N-directing groups. By using simple alkali halides of MX type as the nucleophilic reagent source (M = Li, Na, K, Cs and X = I, Br and Cl), and phenyliodanediacetate oxidant, clean C-H-iodination, bromination and chlorination reactions were performed. This general protocol of selective ortho-monohalogenation, which complements but contrasts with the classical methods using electrophilic reagents, is achievable in a short time (30 min) with microwave irradiation assistance. The reaction was extended to substrates bearing N-directing pyridine, pyrimidine, pyrazole, oxazoline, naphtho[1,2-d]thiazole, and azobenzene groups. Notably, the topical and selectivity-challenging s-tetrazine, as a nitrogen-rich heteroaromatic, was successfully halogenated by this protocol.