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A Ni-catalyzed cascade cyclization of N-acrylamides and unactivated alkyl bromides to synthesize 3,3-disubstituted oxindoles was reported. Up to 22 different oxindole derivatives were synthesized by this method and all the synthesized molecules were tested for inhibitory activity of nitric oxide release. The results show that 3,3-disubstituted oxindole is a potential scaffold to design new nitric oxide release inhibition drugs. [ABSTRACT FROM AUTHOR]

Mn-mediated reductive cross-coupling of organic bromides with 2-bromo-1,3,2-diazaphospholene was developed for efficient construction of C–P bonds under mild conditions. Mechanistic studies suggested that bromides are activated by in situ formed bis-diazaphospholene via hybrid radical and polar mechanisms. [ABSTRACT FROM AUTHOR]

Back electron transfer (BET) in eosin Y (EY) photoredox catalysis was visualized via the fluorescence of single EYs. BET between the radical ion pair formed in photoinduced electron transfer (PET) induced photoblinking of single EYs under constant photoexcitation. Commonly used quenchers, alkyl bromides and a tertiary amine, were studied. BET was observed in alkyl bromides, but not in the tertiary amine. The findings helped explain the mechanism of EY-catalyzed photoinduced atom transfer radical polymerizations. The method can be applied to studying BET on photo-emissive catalysts. [ABSTRACT FROM AUTHOR]

This document provides information about the synthesis and characterization of various compounds, including indazoles and pyrazolopyridines. The compounds were synthesized using specific reactions and purification techniques, and their structures were confirmed using various spectroscopic techniques. The document includes data such as chemical shifts, yields, melting points, and spectroscopic data for each compound. The authors acknowledge the support of the Central Laboratory of Pharmacy at Ankara University and declare no conflicts of interest. [Extracted from the article]

Recent years have witnessed the emergence of direct intermolecular C(sp3)–H bond functionalization using in situ generated aryl/alkyl radicals as a unique class of hydrogen atom transfer (HAT) agents. A variety of precursors have been exploited to produce these radical HAT agents under photocatalytic, electrochemical or thermal conditions. To date, viable aryl radical precursors have included aryl diazonium salts or aryl azosulfones, diaryliodonium salts, O-benzoyl oximes, aryl sulfonium salts, aryl thioesters, and aryl halides; and applicable alkyl radical sources have included tetrahalogenated methanes (e.g., CCl3Br, CBr4 and CF3I), N-hydroxyphthalimide esters, alkyl bromides, and acetic acid. This review summarizes the current advances in direct intermolecular C(sp3)–H functionalization through key HAT events with in situ generated aryl/alkyl radicals and categorizes the procedures by the specific radical precursors applied. With an emphasis on the reaction conditions, mechanisms and representative substrate scopes of these protocols, this review aims to demonstrate the current trends and future challenges of this emerging field. [ABSTRACT FROM AUTHOR]

ABSTRACT The primary objective of this study was to explore the synthesis of novel dihydrocyclopenta[b]pyrrole derivatives with a high degree of efficiency. The work utilized a nanocatalyst composed of Ag/Fe3O4@MWCNTs in a multicomponent reaction including vinilydene aldehydes, ethyl 2‐amino‐4‐dioxo‐4‐arylbutanoates, and alkyl bromides. The reaction was carried out in aqueous solution at ambient temperature, leading to the formation of novel chemicals. The produced compounds exhibit antioxidant activity as a result of the evaluation processes performed on their NH group. Furthermore, an evaluation was performed on the antibacterial effectiveness of newly produced pyridines using a disk diffusion technique, utilizing two different strains of Gram‐negative bacteria. Significantly, the substances that were evaluated shown inhibitory effects on the development of Gram‐positive bacteria as well. This method has several benefits, including quick response times, high product yields, and easy separation of catalyst and product through simple procedures. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A novel visible‐light‐induced radical cascade 6‐endo cyclization of dienes (N‐(2‐vinylphenyl)acryl amides) is developed utilizing α‐carbonyl bromides as alkyl reagents. This approach affords an efficient way for synthesizing six‐membered benzo‐fused lactam derivatives with chemo‐ and regio‐selectivity and good functional group tolerance. Primary, secondary, and tertiary bromides are well‐compatible with this cascade cyclization reaction. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are an attractive class of materials for sensing applications due to their inherent crystallinity, high surface area, and designable framework functionalities. While the majority of COFs have high electrical resistance, making it difficult to harness these materials for electronic sensors, real‐time impedance spectroscopy can enable gas and vapor sensing of a much wider range of COFs. Herein, a set of post‐synthetically modified (PSM) COFs are explored though a straightforward one‐step substitution reaction by reacting phenol moieties on the pore wall, with alkyl bromides, to embed alkyl, aryl, or alcohol groups into the framework. This modular approach provides access to improved sensor properties toward the detection of volatile organics, acids, and potentially harmful gases. Sensor results indicate that post‐synthetically modified COFs offer better sensitivity toward NO2 and acetic acid, with the aryl functionalized COF having an NO2 detection limit of 10 ppm. Furthermore, modified COFs also show higher selectivity toward isopropanol and toluene. This work highlights the importance of methods that facilitate post‐synthetic modification of COFs so that functional groups and COF properties can be tuned. [ABSTRACT FROM AUTHOR]

Ketones, prevalent in many biologically significant molecules, require the development of novel methods to synthesize these structures, which is a critical endeavor in organic synthesis. Transition metal catalysis has proven to be an effective method for synthesizing ketones. However, the scope of these substrates remains relatively limited, particularly due to their incompatibility with sensitive functional groups. Herein, we report a Ni-catalyzed three-component 1,2-carboacylation of alkenes, which activates secondary/tertiary alkyl bromides. This method offers significant advantages: simplicity of operation, ready availability of substrates, and broad substrate applicability. A series of experimental studies have helped clarify the key mechanistic pathways involved in this cascade reaction. [ABSTRACT FROM AUTHOR]

A nickel‐catalyzed reductive alkylative cyclization of 1,6‐enynes with alkyl bromides has been developed. This transformation avoids the use of stoichiometric organometallic reagents and introduces alkyl groups regio‐ and stereoselectively into the products. This method provides a platform for the synthesis of carbo‐ and heterocycles that are widely found in many natural products and biologically active molecules. [ABSTRACT FROM AUTHOR]

Cross‐electrophile coupling (XEC) between aryl halides and alkyl halides is a streamlined approach for C(sp2)−C(sp3) bond construction, which is highly valuable in medicinal chemistry. Based on a key NiII aryl amido intermediate, we developed a highly selective and scalable Ni‐catalyzed electrochemical XEC reaction between (hetero)aryl halides and primary and secondary alkyl halides. Experimental and computational mechanistic studies indicate that an amine secondary ligand slows down the oxidative addition process of the Ni‐polypyridine catalyst to the aryl bromide and a NiII aryl amido intermediate is formed in situ during the reaction process. The relatively slow oxidative addition is beneficial for enhancing the selectivity of the XEC reaction. The NiII aryl amido intermediate stabilizes the NiII–aryl species to prevent the aryl–aryl homo‐coupling side reactions and acts as a catalyst to activate the alkyl bromide substrates. This electrosynthesis system provides a facile, practical, and scalable platform for the formation of (hetero)aryl–alkyl bonds using standard Ni catalysts under mild conditions. The mechanistic insights from this work could serve as a great foundation for future studies on Ni‐catalyzed cross‐couplings. [ABSTRACT FROM AUTHOR]

AbstractAsymmetric gemini surfactants were synthesized by the quaternization reaction of 1-(2-hydroxypropyl)-4-ethyl piperazine with (C9, C10, C12, and C14) alkyl bromides. The surface tension of their aqueous solutions was determined by the Du Nouy ring method and the conductometric method of specific electrical conductivity. According to the concentration dependence graphs of surface tension and specific electrical conductivity, critical micelle concentration – CMC, degree of association of the counterion – β, surface area occupied by the head group of the surfactant – Amin, maximum surface excess concentration – Γmax, effectiveness or surface pressure –πCMC, adsorption efficiency – pC20 were calculated, and the change of these parameters depending on the length of the alkyl chain was determined. Simultaneously, variations in Gibbs free energies of micellization and adsorption processes were computed. The diameters of aggregates formed by asymmetric gemini surfactants in water were determined by the DLS method. Antimicrobial abilities of asymmetric gemini surfactants against gram positive and gram negative bacteria and fungi were defined by the disk diffusion method. [ABSTRACT FROM AUTHOR]

Classical methods for the synthesis of tertiary alcohols mainly rely on the nucleophilic addition of organometallic reagents to carbonyl compounds. Here, we disclose a strategy for synthesizing tertiary alcohols via electroreductive cross‐electrophile coupling of aromatic carbonyl compounds and alkyl bromides (allyl, propargyl, benzyl and cyclohexyl bromides). This procedure features good substrate tolerance and friendly conditions (undivided cell, cheap and reusable carbon electrodes, reaction in open air, room temperature, without any external transition metal/activating reagent). Using this method, 32 desired products can be obtained with moderate to good yields, and gram‐scale synthesis is feasible, demonstrating the practicality of this approach. [ABSTRACT FROM AUTHOR]

New, high‐yield derivatives of oxepino[3,2‐c]chromene were synthesized through a multicomponent reaction. This reaction involved 2‐hydroxyacetophenone, dimethyl carbonate, activated acetylenic compounds, and alkyl bromide. The reaction took place at room temperature in an aqueous environment, resulting in the formation of these innovative compounds. Oxathiepines were synthesized using multicomponent reactions of 2‐hydroxyacetophenone, dimethyl carbonate, isothiocyanate, and alkyl bromide in water at room temperature. This technology offers several benefits, including quick response times, high product yields, and easy product separation using straightforward techniques. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Cross‐electrophile couplings (XEC), a crucial subset of cross‐coupling reactions, center on the formation of robust C—C bonds through the union of two electrophiles. Usually, such reactions have primarily been catalyzed by transition metals. However, with the steady advancements in photochemical and electrochemical technologies, XEC reactions have significantly progressed and broadened their scope, allowing for the utilization of a wider array of tolerable functional groups, thus revealing vast application prospects. This review aims to systematically summarize the current prevalent types of electrophiles and delve into their specific application examples within XEC reactions involving electrophiles with identical functional groups. Specifically, XECs between the same type of halides have received considerable attention, whereas carboxylic acids and alcohols are still in the early stages of investigation. Furthermore, certain other common electrophiles remain unexplored in this context. Moreover, this review underscores the remarkable contributions of photochemistry and electrochemistry in the field of XEC reactions, aiming to provide valuable insights and inspiration for researchers. Also, this review hopes to spark further interest in XEC reactions, thereby fueling the continuous development and advancement of this exciting area of research. Key Scientists: Since the 1960s, advancements in the XEC reaction have been substantial, driven primarily by the application of transition metal catalysts. In this area, many distinguished scientists have contributed their wisdom and efforts. Particularly noteworthy is that, during the systematic study of XEC reactions with the identical functional groups, in 2016, MacMillan achieved a photocatalytic XEC reaction between aryl bromides and alkyl bromides; in 2020, Weix successfully realized a nickel‐catalyzed XEC reaction between aryl chlorides and alkyl chlorides. Concurrently, contributions from researchers such as Mei, Wolf, Sevov, Lin, Shen, Browne, Zhang, and Qiu have expanded the scope of XEC reactions to various halides. By 2022, MacMillan and Baran achieved a significant milestone in the XEC between carboxylic acids, further broadening the scope of research in this area. Also, advancements in the XEC of alcohols have been noted, with researchers including Weix, Lian, Tu, and Stahl conducting pioneering work and successfully executing the XEC of protective groups. It is foreseen that the ongoing research endeavors will primarily concentrate on the expansion of diverse electrophiles. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Organofluorine compounds have attracted substantial interest in life and materials sciences due to the unique properties of fluorine atom(s) that often change the physicochemical and biological properties of organic molecules. Transition‐metal‐mediated cross‐electrophile coupling between carbon electrophiles and fluoroalkyl electrophiles has emerged as a straightforward and efficient route for the synthesis of a wide range of fluoroalkylated compounds because of its synthetic convenience without the tedious synthesis of organometallic reagents. Moreover, alkenes or alkynes‐involved three‐component cross‐electrophile couplings provide rapid and effective access to carbonfunctionalized fluoroalkylated alkanes and alkenes. Herein, we comprehensively summarize the transition‐metal‐mediated reductive fluoroalkylation of diverse carbon electrophiles through a historical perspective, including trifluoromethylation, difluoroalkylation, monofluoroalkylation, and so on. Different transition metals (Cu, Ni, etc.) and strategies are discussed, in which nickel‐catalyzed reductive fluoroalkylation reactions represent an attractive and efficient synthetic route to site‐selectively access organofluorine compounds. Key Scientists: As early as 1965, McLoughlin and Thrower finished the first stoichiometric copper‐mediated fluoroalkylation of aromatic iodides with fluoroalkyl iodides. However, excess aromatic iodides and elevated temperature were used for this method. In 1969, Kobayashi and Kumadaki reported studies on the copper‐mediated trifluoromethylation of aromatic halides with excess trifluoromethyl iodide. After more than four decades, the Zhang group developed a nickel‐catalyzed β‐fluorinated alkylation of (hetero)aryl iodides with fluoroalkylated secondary alkyl bromides in 2015, and a nickel‐catalyzed difluoromethylation of (hetero)aryl chlorides with chlorodifluoromethane ClCF2H in 2017. The Zhang group also developed enantioselective nickel‐catalyzed reductive alkyl‐arylation of 3,3,3‐trifluoropropene with (hetero)aryl and tertiary alkyl iodides. In 2018, the MacMillan group developed a novel copper/photoredox dual catalytic system for the trifluoromethylation of aryl bromides or alkyl bromides with (S)‐(trifluoromethyl) dimesitylsulfonium triflate in the presence of tris‐(trimethylsilyl) silanol. They also developed a nickel/photoredox catalyzed difluoromethylation of aryl bromides in the presence of silane. During this time, the Wang group reported a nickel‐catalyzed monofluoroalkylation of aryl halides with monofluoroalkyl halides. From 2021 to 2023, the same group further developed a series of enantioselective nickel‐catalyzed trifluoroalkylation of aryl, alkenyl, and acyl halides. Moreover, nonfluorinated alkenes or alkynes could also be used in three‐component cross‐electrophile couplings. In 2018, the Chu group reported a nickel‐catalyzed fluoroalkyl‐acylation of alkenes with acyl chlorides and fluoroalkyl iodides. Later, they developed a nickel‐catalyzed enantioselective fluoroalkyl‐arylation of unactivated alkenes tethering with a pendant chelating group. In 2019, the Chaładaj group reported a palladium‐catalyzed reductive perfluoroalkyl‐arylation of alkynes with perfluoroalkyl and aryl iodides. [ABSTRACT FROM AUTHOR]

A new nickel-catalyzed electrochemical, reductive cross-coupling for the trideuteromethylation of alkyl and aryl bromides is reported in which CD3 arenesulfonate derivatives were used as effective and readily available CD3 sources. The CD3-labeled products were obtained with good yields. It was demonstrated that this methodology is scalable and can be efficiently used for various methylations, including13 CH3 and13 CD3 labeling. [ABSTRACT FROM AUTHOR]

By using a multicomponent reaction involving isatins, diamines or aminoalcohols, activated acetylenic compounds, haloketones, and ammonium acetate in aqueous media in the presence of Cu@Fe3O4/SiO2@MWCNTs as new catalyst, the novel pyridopyrroloindole was produced in high yields. This catalyst was produced by employing Petasites hybridus rhizome water extract as a green media and moderate base. The pyridopyrroloindole derivatives were newly synthesized compounds, and their antioxidant properties were assessed using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical trapping and ferric reducing ability of plasma (FRAP) experiments. The pyridopyrroloindole 6b showed higher performance than butylated hydroxytoluene (BHT) and tert‐butylhydroquinone (TBHQ) better results. This method is used to make pyridopyrroloindole derivatives, and it has the advantages of a quick reaction, high yields, and the ability to separate the products easily. [ABSTRACT FROM AUTHOR]

Herein, we report a synergistic photoredox/palladium catalytic system for the efficient enantioconvergent synthesis of axially chiral esters from racemic heterobiaryl (pseudo)halides (bromides/triflates) with CO2 and alkyl bromides under mild conditions. A wide range of axially chiral esters were obtained in good to high yields with excellent enantioselectivities. Detailed mechanistic studies unveiled that the ratio of photocatalyst and palladium catalyst exhibited significant impact on the chemo‐ and enantioselectivities of the reaction. Kinetic studies and control experiments supported the proposed mechanism involving cascade asymmetric carboxylation followed by SN2 substitution. The achievement of high enantioselectivity relies not only on the choice of synergistic metallaphotoredox catalysts but also on the utilization of alkyl bromides, which trap the generated chiral carboxylic anions in situ, thus preventing their immediate racemization. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: An alkyl radical initiated cyclization/tandem reaction of alkyl bromides and alkyl electrophiles by using potassium metabisulphite (K2S2O5) as a connector is developed for the synthesis of various lactam‐substituted alkyl sulfones. Notably, this process does not require a metal catalyst or metal powder reductant, highlighting its environmentally friendly features. The reaction demonstrates outstanding substrate adaptability and a high tolerance towards diverse functional groups. Furthermore, the biologically active molecules and commercially available drugs with a late‐stage modification are also highly compatible with this transformation. Mechanistic studies revealed that the reaction proceeds through a single‐step process involving intramolecular radical cyclization, "SO2" insertion, and external alkyl incorporation. [ABSTRACT FROM AUTHOR]

A visible‐light‐mediated radical heteroarylation of 2‐mercaptothiazolinium salts with N‐heteroarenes is reported, furnishing the corresponding functionalized N‐heteroarenes in good to high yields. Various alkyl bromides were converted conveniently into redox‐active thiazolinium salts and subsequently into alkyl radicals by reaction with an excited‐state photocatalyst. This mild protocol permits efficient functionalization of various N‐heteroarenes with a wild range of cyclic and acyclic primary and secondary alkyl groups. [ABSTRACT FROM AUTHOR]

Introduction: New Delhi Metallo-β-lactamase producing Klebsiella pneumoniae (NDM-1-KP) sequence type (ST) 147 poses a significant threat in clinical settings due to its evolution into two distinct directions: hypervirulence and carbapenem resistance. Hypervirulence results from a range of virulence factors, while carbapenem resistance stems from complex biological mechanisms. The NDM-1-KP ST147 clone has emerged as a recent addition to the family of successful clones within the species. Methods: In this study, we successfully synthesized 5-bromo-N-alkylthiophene-2-sulfonamides (3a-c) by reacting 5-bromothiophene-2-sulfonamide (1) with various alkyl bromides (2) using LiH. We also synthesized a series of compounds (4a-g) from compound (3b) using the Suzuki-Miyaura cross-coupling reaction with fair to good yields (56– 72%). Further, we screened the synthesized molecules against clinically isolated New Delhi Metallo-β-lactamase producing Klebsiella pneumoniae ST147. Subsequently, we conducted in-silico tests on compound 3b against a protein extracted from NDM-KP ST147 with PDB ID: 5N5I. Results: The compound (3b) with favourable drug candidate status, MIC of 0.39 μg/mL, and MBC of 0.78 μg/mL. This low molecular weight compound exhibited the highest potency against the resistant bacterial strains. The in-silico tests revealed that the compound 3b against a protein extracted from NDM-KP ST147 with PDB ID: 5N5I demonstrated H-bond and hydrophobic interactions. Conclusion: The 5-bromo-N-alkylthiophene-2-sulfonamides displayed antibacterial efficacy against New Delhi Metallo-β-lactamase producing Klebsiella pneumoniae ST147. After the in-vivo trial, this substance might offer an alternative therapeutic option. [ABSTRACT FROM AUTHOR]

The reaction of 3,4-dihydro-2H-thiopyrane-1,1-dioxide and 3,4,6-triphenyl-3,4-dihydro-2H-thiopyrane-1,1-dioxide alkylation is studied by a DFT quantum chemical simulation using the REVPBE0 functional. Geometric parameters of initial compounds, products, transition states, and Gibbs free energies of activation are calculated. The influence of the steric factor on the reaction regioselectivity is demonstrated. [ABSTRACT FROM AUTHOR]

Olefin hydrogenation is one of the most important transformations in organic synthesis. Electrochemical transition metal‐catalyzed hydrogenation is an attractive approach to replace the dangerous hydrogen gas with electrons and protons. However, this reaction poses major challenges due to rapid hydrogen evolution reaction (HER) of metal‐hydride species that outcompetes alkene hydrogenation step, and facile deposition of the metal catalyst at the electrode that stalls reaction. Here we report an economical and efficient strategy to achieve high selectivity for hydrogenation reactivity over the well‐established HER. Using an inexpensive and bench‐stable nickel salt as the catalyst, this mild reaction features outstanding substrate generality and functional group compatibility, and distinct chemoselectivity. In addition, hydrodebromination of alkyl and aryl bromides could be realized using the same reaction system with a different ligand, and high chemoselectivity between hydrogenation and hydrodebromination could be achieved through ligand selection. The practicability of our method has been demonstrated by the success of large‐scale synthesis using catalytic amount of electrolyte and a minimal amount of solvent. Cyclic voltammetry and kinetic studies were performed, which support a NiII/0 catalytic cycle and the pre‐coordination of the substrate to the nickel center. [ABSTRACT FROM AUTHOR]

Herein, we report a mild and practical method for the deuteration of alkyl and aryl bromides by a thiyl radical catalyst and halogen-atom transfer (XAT) using disulfides and silanes under visible-light irradiation. In this study, various organic bromides such as 1°, 2°, and 3°-alkyl bromides and aryl bromides were converted to deuterated products in good to excellent yields and D-incorporation. [ABSTRACT FROM AUTHOR]

A C(sp3)–C(sp3) cross coupling approach based on an iridium-photocatalytic radical process has been developed enabling the synthesis of various α-alkylated aldehydes from easily available/synthesized alkyl bromides and trialkyl amines under mild photocatalytic conditions. The synthesized aldehydes are also explored as a functional handle for various useful products such as carboxylic acid, alcohol and N-heterocycle synthesis. [ABSTRACT FROM AUTHOR]

We have developed a novel Ni-catalyzed reductive cross-coupling reaction of aryl bromides and alkyl iodides via a photoactive electron donor–acceptor (EDA) complex. This photo-induced process enables the efficient construction of C(sp2)–C(sp3) bonds in the absence of an external photocatalyst. Electronically and structurally diverse aryl bromides, as well as secondary and primary alkyl iodides could undergo this transformation smoothly. Natural product derivatives were employed successfully, and UV-vis spectroscopy was utilized to gain mechanistic insight. [ABSTRACT FROM AUTHOR]

A novel and efficient method for functionalizing organosulfones has been established, utilizing a visible-light-driven intermolecular radical cascade cyclization of α-allyl-β-ketosulfones. This process employs fac-Ir(ppy)3 as the photoredox catalyst and α-carbonyl alkyl bromide as the oxidizing agent. Via this approach, the substrates experience intermolecular addition of α-carbonyl alkyl radicals to the alkene bonds, initiating a sequence of C-C bond formations that culminate in the production of organosulfone derivatives. Notably, this technique features gentle reaction conditions and an exceptional compatibility with a wide array of functional groups, making it a versatile and valuable addition to the field of organic synthesis. [ABSTRACT FROM AUTHOR]

Fixing the greenhouse gas CO2 through epoxide helps to mitigate worldwide ecological troubles. The applications of metal‐free and solvent‐free catalysts remain a challenge for CO2 catalytic conversion. In this work, an array of quaternary ammonium salts derived from polyethyleneimine with hydroxyl groups ([PEI‐GDMAB‐Cn]Br) were constructed by the reaction of branched PEI with a molecular weight of 10000 and glycidyl alkyl dimethylammonium bromide. A range of experiments were designed to demonstrate that [PEI‐GDMAB‐Cn]Br can be considered as a valid metal‐free and solvent‐free homogeneous catalyst for the CO2‐epoxide cycloaddition reaction. Among of [PEI‐GDMAB‐Cn]Br, [PEI‐GDMAB‐C18]Br catalyzed the model reaction of CO2 and epichlorohydrin under optimized reaction conditions (T=80 °C, 1.0 atm CO2, catalyst 1 mol%, ECH 15 mmol, 16 h) and the conversion achieved at 97.5 %. Moreover, the catalyst exhibited stable reusability and broad substrate applicability, which was used in the following cycle succinctly, because of self‐separated properties by temperature control. The [PEI‐GDMAB‐C18]Br catalyzed reaction process was detected as a pseudo‐first‐order reaction after kinetic studies and an Ea was calculated to be 50.65 kJ/mol. A combinatorial catalytic mechanism of hydrogen bonding and bromide ions is suggested to explain the remarkable catalytic performance of this bifunctional catalyst. [ABSTRACT FROM AUTHOR]

A selective C(sp3)−S bond cleavage of thioethers mediated by NBS is developed. Various alkyl bromides have been obtained in good yields using N‐aryl‐3‐(methylthio)propanamides and arylmethylene alkylthioethers. Mechanistic studies suggest that the formation of 3‐bromo‐N‐arylpropanamides may involve sulfoxide intermediates, while the arylmethylene bromides are formed through direct bromination process mediated by NBS. The significance of this strategy lies in its pioneering use of NBS for C−S bond cleavage and subsequent bromination reaction. [ABSTRACT FROM AUTHOR]

Herein, a sensitive and selective gas chromatography-electron capture detector (GC-ECD) method was developed and validated for the quantification of trace levels of five bromo-containing genotoxic impurities in Febuxostat active pharmaceutical ingredient (API) after headspace sampling (HS). Multivariate experimental designs for the optimization of static headspace parameters were conducted in two stages using fractional factorial design (FFD) and central composite design (CCD). The optimum headspace conditions were 5 min of extraction time and a 120 °C extraction temperature. Baseline separation on the analytes against halogenated solvents was carried out using an Agilent DB-624 (30 m × 0.32 mm I.D., 1.8 μm film thickness) stationary phase under isothermal conditions. The method was validated according to ICH guidelines in terms of specificity, linearity, the limits of detection and quantification, precision and accuracy. The linearity was assessed in the range of 5–150% with respect to the specification limit. The achieved LOD and LOQ values ranged between 0.003 and 0.009 and 0.01 and 0.03 μg mL−1, respectively. The accuracy of the method (expressed as relative recovery) was in the range of 81.5–118.2%, while the precision (repeatability, inter-day) was less than 9.9% in all cases. The validated analytical protocol has been successfully applied to the determination of the impurities in various Febuxostat API batch samples. [ABSTRACT FROM AUTHOR]

In this study, we synthesized azepinodiazepine derivatives in high yields using multicomponent reactions of isatins, activated acetylenic compounds, alkyl bromides, methyl aziridine and ammonium acetate in the presence of Fe3O4/ZnO@MWCNT as a high-performance catalyst and teiethyl amine in water at room temperature. The Fe3O4/ZnO@MWCNT synthesizes using Petasites hybridus rhizome water extract as a green media and moderate base. Also, the catalytic activity of the green synthesized Fe3O4/ZnO@MWCNT MNCs was evaluated in the reduction of organic pollutants such as 4-nitrophenol (4-NP) in water at mild conditions. The results indicated that the biosynthesized NCs have very high and effective catalytic activity for organic pollutants within a few seconds. Investigation of the antioxidant ability of synthesized compounds using radical trapping of diphenyl-picrylhydrazine (DPPH) and ferric reduction power experiment is another purpose of this research. Also, the antimicrobial activity of some synthesized compounds was proved by employing the disk diffusion test on Gram-positive and Gram-negative bacteria. Also, to better understanding reaction mechanism density functional theory (DFT) based quantum chemical methods have been applied. This procedure has some benefits such as short reaction time, products with excellent yields, simple catalyst and product separation. Green chemistry is the use of a set of principles to reduce or eliminate the use or generation of unsafe materials in the design, fabrication and applications of chemical products. Among solvents, water is a green solvents and very suitable for performing organic reaction. The present procedure avoids the use of toxic solvent. Some representatives of this class of azaheterocycles are known as antiviral agents, glycosidase inhibitors, anticancer agents or antidiabetics. Therefore, in view of their medicinal relevance, an increasing number of synthetic methods have been described in recent years for the construction of highly substituted azepine derivatives. [ABSTRACT FROM AUTHOR]

A reductive cross-coupling strategy for the synthesis of sulfone-containing oxindoles via palladium-catalyzed domino cyclization/alkylsulfonylation reaction of N-substituted arylacrylamides with unactivated alkyl bromides and Na2S2O5 is presented. Moreover, using amines instead of alkyl bromides, a palladium-catalyzed domino cyclization/aminosulfonylation was also established. [ABSTRACT FROM AUTHOR]

A reductive cross-coupling strategy for the synthesis of sulfone-containing oxindoles via palladium-catalyzed domino cyclization/alkylsulfonylation reaction of N-substituted arylacrylamides with unactivated alkyl bromides and Na2S2O5 is presented. Moreover, using amines instead of alkyl bromides, a palladium-catalyzed domino cyclization/aminosulfonylation was also established. [ABSTRACT FROM AUTHOR]

Silylzinc reagents are desirable for the synthesis of organosilanes due to their compatibility with functional groups; however, the use of pyrophoric silyllithium and dissolved lithium salts in their production hinders their development. Our solid Me3SiZnI circumvents these limitations, and herein, we demonstrate its significance in the synthesis of aryl and alkyl trimethylsilanes via cross‐coupling of aryl and alkyl bromides. The milder reaction condition tolerates functional groups such as MOM, Boc, Bpin, and aldehydes. [ABSTRACT FROM AUTHOR]

gem‐Dibromoalkanes are important synthetic building block in organic chemistry, but their preparation is still troublesome. Herein, we have developed a simple and practical protocol for the synthesis of gem‐dibromoalkanes from aldehydes using tetrabutylammonium tribromide and triphenyl phosphite. A variety of alkyl and aromatic aldehydes can be transformed into the corresponding products within 10 minutes. This protocol is also applicable to alcohols, and the configuration of chiral alcohol is inverted during the process with excellent enantiopurity. [ABSTRACT FROM AUTHOR]

Ketones, prevalent in many biologically significant molecules, require the development of novel methods to synthesize these structures, which is a critical endeavor in organic synthesis. Transition metal catalysis has proven to be an effective method for synthesizing ketones. However, the scope of these substrates remains relatively limited, particularly due to their incompatibility with sensitive functional groups. Herein, we report a Ni-catalyzed three-component 1,2-carboacylation of alkenes, which activates secondary/tertiary alkyl bromides. This method offers significant advantages: simplicity of operation, ready availability of substrates, and broad substrate applicability. A series of experimental studies have helped clarify the key mechanistic pathways involved in this cascade reaction.

Sulfonyl groups are widely observed in biologically relevant molecules and consequently, SO2 capture is an increasingly attractive method to prepare these sulfonyl‐containing compounds given the range of SO2‐surrogates now available as alternatives to using the neat gas. This, along with the advent of photoredox catalysis, has enabled mild radical capture of SO2 to emerge as an effective route to sulfonyl compounds. Here we report a photoredox‐catalyzed cross‐electrophile sulfonylation of aryl and alkyl bromides making use of a previously under‐used amine‐SO2 surrogate; bis(piperidine) sulfur dioxide (PIPSO). A broad selection of alkyl and aryl bromides were photocatalytically converted to their corresponding sulfinates and then trapped with various electrophiles in a one‐pot multistep procedure to prepare sulfones and sulfonamides. [ABSTRACT FROM AUTHOR]

Transition metal-catalyzed asymmetric cyclization of 1,6-enynes is a powerful tool for the construction of chiral nitrogen-containing heterocycles. Despite notable achievements, these transformations have been largely limited to the use of aryl or alkenyl metal reagents, and stereoselective or stereospecific alkylative cyclization of 1,6-enynes remains unexploited. Herein, we report Ni-catalyzed enantioselective reductive anti-arylative cyclization of 1,6-enynes with aryl iodides, providing enantioenriched six-membered carbo- and heterocycles in good yields with excellent enantioselectivities. Additionally, we have realized Ni-catalyzed enantiospecific reductive cis-alkylative cyclization of 1,6-enynes with alkyl bromides, furnishing chiral five-membered heterocycles with high regioselectivity and stereochemical fidelity. Mechanistic studies reveal that the arylative cyclization of 1,6-enynes is initiated by the oxidative addition of Ni(0) to aryl halides and the alkylative cyclization is triggered by the oxidative addition of Ni(0) to allylic acetates. The utility of this strategy is further demonstrated in the enantioselective synthesis of the antiepileptic drug Brivaracetam. Transition metal-catalyzed asymmetric cyclization of 1,6-enynes is a powerful tool for the construction of chiral nitrogen-containing heterocycles, but limiting to the use of aryl or alkenyl metal reagents. Here, the authors report Ni-catalyzed enantioselective anti-arylative cyclization and enantiospecific cis-alkylative cyclization of 1,6-enynes. [ABSTRACT FROM AUTHOR]

A cobalt‐catalyzed 1,2‐regioselective dicarbofunctionalization of silylated 1,3‐dienes with functionalized solid organozinc pivalates and alkyl bromides is disclosed, thus affording the alkylarylated and dialkylated silanes in a regioselective manifold. Herein, regioselectivity is steered by steric hindrance of the bulky silyl groups, which could prohibit the formation of the flexible π‐allylcobalt intermediate. Furthermore, derivatizations of the resulting products and modifications of bioactive molecules demonstrate the synthetical utility of our method. [ABSTRACT FROM AUTHOR]

The present work represents the propyl modification and characterization of Moringa gum for sustained drug delivery applications. The propylation of Moringa gum was performed using n-propyl bromide by alkyl etherification process. The propylated Moringa gum was further evaluated as a diclofenac sodium-loaded matrix tablet and composite beads for sustained drug delivery. The modification of Moringa gum was confirmed by infrared spectroscopy. The degree of propyl substitution was determined to be 0.407. The characterization studies revealed the increase in the degree of crystallinity, thermal stability, surface roughness, and the decrease in viscosity on propyl modification. The native and modified gum had a molecular weight of 1.02 × 104 and 4.84 × 104 KDa, respectively. The diclofenac-loaded matrix tablets of Moringa gum disintegrated in simulated gastric fluid, while tablets of propyl Moringa gum provided sustained release of diclofenac by super case 2 transport following Higuchi release kinetics. The ionically gelled beads of propyl Moringa gum were able to control the burst release of diclofenac in simulated gastric fluid releasing 84% of the drug in 24 h following Higuchi kinetics. It can be concluded that the propyl-modified Moringa gum can be used as a pharmaceutical excipient for sustained drug delivery applications. [ABSTRACT FROM AUTHOR]

The synthesis of bis-quaternary ammonium compounds based on a polyhydric alcohol, 2,3-bis(hydroxymethyl)butane-1,4-diol, and pyridine was accomplished. The bacteriostatic and bactericidal activity of the products against ESKAPE pathogens and Candida albicans yeast-like fungus both in planktonic and biofilm forms was studied. The activity of the bis-pyridinium salts was compared with the activities of known antiseptic agents, octenidine dihydrochloride and cetylpyridinium chloride. It was found that the compound containing ten carbon atoms in the alkyl group is effective against various strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and C. albicans. [ABSTRACT FROM AUTHOR]

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Reactions of unactivated alkyl chlorides under mild and sustainable conditions are rare compared to those of alkyl bromides or iodides. As a result, synthetic methods capable of modifying the vast chemical space of chloroalkane reagents, wastes, and materials are limited. We report the cobalt‐catalyzed reductive addition of unactivated alkyl chlorides to conjugated alkenes. Co‐catalyzed activation of alkyl chlorides is performed under electroreductive conditions, and the resulting reactions constitute formal alkyl‐alkyl bond formation. In addition to developing an operationally simple methodology, detailed mechanistic studies provide insights into the elementary steps of a proposed catalytic cycle. In particular, we propose a switch in the mechanism of C−Cl bond activation from nucleophilic substitution to halogen atom abstraction, which is critical for efficiently generating alkyl radicals. These mechanistic insights were leveraged in designing ligands that enable couplings of primary, secondary, and tertiary alkyl chlorides. [ABSTRACT FROM AUTHOR]

The precise control of the regioselectivity in the transition metal‐catalyzed migratory hydrofunctionalization of alkenes remains a big challenge. With a transient ketimine directing group, the nickel‐catalyzed migratory β‐selective hydroarylation and hydroalkenylation of alkenyl ketones has been realized with aryl boronic acids using alkyl halide as the mild hydride source for the first time. The key to this success is the use of a diphosphine ligand, which is capable of the generation of a Ni(II)‐H species in the presence of alkyl bromide, and enabling the efficient migratory insertion of alkene into Ni(II)‐H species and the sequent rapid chain walking process. The present approach diminishes organosilanes reductant, tolerates a wide array of complex functionalities with excellent regioselective control. Moreover, this catalytic system could also be applied to the migratory hydroarylation of alkenyl azahetereoarenes, thus providing a general approach for the preparation of 1,2‐aryl heteroaryl motifs with wide potential applications in pharmaceutical discovery. [ABSTRACT FROM AUTHOR]

In this study, we synthesized azepinooxazepine derivatives in high yields using multicomponent reactions of aniline, diethyl carbonate, alkyl bromides, activated acetylenic compounds, methyl aziridine and Fe3O4/ZnO@MWCNT as a high performance catalyst and teiethyl amine in water at room temperature. The catalytic activity of the green synthesized Fe3O4/ZnO@MWCNT MNCs was evaluated in the reduction of organic pollutants such as 4-nitrophenol (4-NP) in water at mild conditions. The results indicated that the biosynthesized NCs have very high and effective catalytic activity for organic pollutants within few seconds. Investigation of antioxidant ability of synthesized compounds using radical trapping of DPPH and ferric reduction power experiment is another purpose in this research. Also, the antimicrobial activity of some synthesized compounds proved by employing the disk diffusion test on Gram-positive and Gram-negative bacteria. Also, density functional theory (DFT) based quantum chemical methods have been applied for better understanding reaction mechanism. Green chemistry is the use of a set of principles to reduce or eliminate the use or generation of unsafe materials in the design, fabrication and applications of chemical products. Among solvents, water is a green solvents and very suitable for performing organic reaction. The present procedure avoids the use of toxic solvent. Some representatives of this class of azaheterocycles are known as antiviral agents, glycosidase inhibitors, anticancer agents or antidiabetics. Therefore, in view of their medicinal relevance, an increasing number of synthetic methods have been described in recent years for the construction of highly substituted azepine derivatives. [ABSTRACT FROM AUTHOR]

Electrochemical approaches to form C(sp2)−C(sp3) bonds have focused on coupling C(sp3) electrophiles that form stabilized carbon‐centered radicals upon reduction or oxidation. Whereas alkyl bromides are desirable C(sp3) coupling partners owing to their availability and cost‐effectiveness, their tendency to undergo radical‐radical homocoupling makes them challenging substrates for electroreductive cross‐coupling. Herein, we disclose a metal‐free regioselective cross‐coupling of 1,4‐dicyanobenzene, a useful precursor to aromatic nitriles, and alkyl bromides. Alkyl bromide reduction is mediated directly by 1,4‐dicyanobenzene radical anions, leading to negligible homocoupling and high cross‐selectivity to form 1,4‐alkyl cyanobenzenes. The cross‐coupling scheme is compatible with oxidatively sensitive and acidic functional groups such as amines and alcohols, which have proven difficult to incorporate in alternative electrochemical approaches using carboxylic acids as C(sp3) precursors. [ABSTRACT FROM AUTHOR]

A method is developed for preparing 18O‐labeled esters through a Ni‐catalyzed three‐component reaction of amides, alkyl halides, and 18O‐labeled water. This method demonstrated excellent selectivity and compatibility with various amides and alkyl halides, allowing the synthesis of diverse isotopically labelled esters. Ni‐catalyzed reaction of alkyl bromides, carboxylates that generated from amides, and water in the presence of a base formed the desired esters. [ABSTRACT FROM AUTHOR]

Carbon-introducing difunctionalization of C-C double bonds enabled by transition-metal catalysis is one of most straightforward and efficient strategies to construct C-C and C-X bonds concurrently from readily available feedstocks towards structurally diverse molecules in one step; however, analogous difunctionalization for introducing germanium group and other functionalities remains elusive. Herein, we describe a nickel-catalyzed germylative alkylation of activated olefins with easily accessible primary, secondary and tertiary alkyl bromides and chlorogermanes as the electrophiles to form C-Ge and C-Calkyl bonds simultaneously. This method provides a modular and facile approach for the synthesis of a broad range of alkylgermanes with good functional group compatibility, and can be further applied to the late-stage modification of natural products and pharmaceuticals, as well as ligation of drug fragments. More importantly, this platform enables the expedient synthesis of germanium substituted ospemifene-Ge-OH, which shows improved properties compared to ospemifene in the treatment of breast cancer cells, demonstrating high potential of our protocol in drug development. While carbon-introducing difunctionalization of C-C double bonds is well established, the analogous difunctionalization for introducing germanium group and other functionalities remains elusive. Here, the authors describe a nickel-catalyzed germylative alkylation of activated olefins with easily accessible primary, secondary and tertiary alkyl bromides and chlorogermanes as the electrophiles to form C-Ge and C-Calkyl bonds simultaneously. [ABSTRACT FROM AUTHOR]

Recent publications on direct reactions of elemental phosphorus with organic halides (alkyl bromides, aryl (and hetaryl) halides, and aryl (and hetaryl) methyl halides) in the presence of superbasic and micellar catalysts are considered. The development of effective, technologically and environmentally acceptable methods for obtaining alkyl(and benzyl)-H-phosphinic and alkylphosphonic acids, triaryl(and hetaryl)phosphines and hetarylmethylphosphine oxides based on the above reactions is analyzed. [ABSTRACT FROM AUTHOR]