Synthetic Method Research Articles

Green Approach Toward Triazole Forming Reactions for Developing Anticancer Drugs.

Compounds containing triazole have many significant applications in the dye and ink industry, corrosion inhibitors, polymers, and pharmaceutical industries. These compounds possess many antimicrobial, antioxidant, anticancer, antiviral, anti-HIV, antitubercular, and anticancer activities. Several synthetic methods have been reported for reducing time, minimizing synthetic steps, and utilizing less hazardous and toxic solvents and reagents to improve the yield of triazoles and their analogues synthesis. Among the improvement in methods, green approaches towards triazole forming biologically active compounds, especially anticancer compounds, would be very important for pharmaceutical industries as well as global research community. In this article, we have reviewed the last five years of green chemistry approaches on click reaction between alkyl azide and alkynes to install 1,2,3-triazole moiety in natural products and synthetic drug-like molecules, such as in colchicine, flavanone cardanol, bisphosphonates, thiabendazoles, piperazine, prostanoid, flavonoid, quinoxalines, C-azanucleoside, dibenzylamine, and aryl-azotriazole. The cytotoxicity of triazole hybrid analogues was evaluated against a panel of cancer cell lines, including multidrug-resistant cell lines.

A Review on the Recent Progress of Layered Double Hydroxides (LDHs)-based Catalysts for Heterocyclic Synthesis

Abstract: Over the past decade, heterocyclic compounds and their derivatives have emerged as promising substances with potential pharmacological applications due to their interesting biological properties. The significance of heterocyclic compounds in drug discovery and development is evident from the fact that a majority of drugs in the pharmaceutical market incorporate heterocyclic compounds as active substances or ingredients. Various synthetic methods and advancements have been devised to prepare these heterocyclic compounds using diverse catalysts under mild conditions. Layered double hydroxides (LDHs)-based materials have gained considerable attention across different fields, and their usability can be significantly enhanced via the selection of metal cations, their molar ratios, surface complexation, and intercalation modifications. The synthesis and application of LDH-based materials as catalysts have garnered increasing interest due to their exceptional properties. Moreover, LDH-based materials have found extensive use as heterogeneous catalysts in the synthesis of numerous heterocyclic compounds. This review presents the latest developments in the catalytic application of LDH-based materials as solid heterogeneous catalysts in the synthesis of heterocyclic compounds, covering literature published from 2018 to 2023.

Flavonoid-metal ion Complexes as Potent Anticancer metallodrugs: A comprehensive Review.

Flavonoids and their analogous are mainly found in pink lady apples, green and black tea (catechins), celery and red peppers, onions, broccoli and spinach, berries, cherries, soybean, citrus fruits, and fungi. The different derivatives of flavonoids belonging to polyphenolic compounds such as 3,4',5,7-Tetrahydroxyflavylium (pelargonidin), 2-(3,4-Dihydroxyphenyl)chromenylium-3,5,7-triol (cyanidin), 3,3',4',5,5',7-Hexahydroxyflavylium (delphinidin), 3,3',4',5,7-Pentahydroxy-5'-methoxyflavylium (petunidin), and 3,4',5,7-Tetrahydroxy-3',5'-dimethoxyflavylium (malvidin) can act as good chelating agents for metal-chelate complex formation. These flavonoid-metal complexes have been reported to have various biomedical and pharmacological activities. Flavonoid-metal ion complexes display a broad spectrum of biological properties such as antioxidant, anti-inflammatory, anti-allergic, antiviral, anticarcinogenic, and cytotoxic activity. The literature survey showed that flavonoid metal complexes have potential therapeutic properties against various cancerous cells. The objective is to gain insight into the current perspective and development of novel anticancer metallodrug drugs. The flavonoid-metal ion complexes can be prepared by reacting flavonoid ligand with appropriate metal salt in aqueous or alcoholic reaction medium under stirring or refluxing conditions. In this review article, the various reported methods for the synthesis of flavonoid-metal complexes have been included. The utility of synthetic methods for flavonoid-metal complexes will support the discovery of novel therapeutic drugs. In this review study, short libraries of flavonoid-metal ion complexes were studied as potential anticancer agents against various human cancer cell lines. The review report reveals that metal ions such as Fe, Co, Ni, Cu, Zn, Rh, Ru, Ga, Ba, Sn etc., when binding to flavonoid ligands, enhance the anticancer activity compared to free ligands. This review study covered some important literature surveys for the last two decades. It has been concluded that flavonoid metal complexes have been associated with a wide range of biological properties that could be noteworthy in the medicinal field. Therefore, to develop a new anticancer drug, it is essential to determine the primordial interaction drug with DNA under physiological or anatomical conditions. The study of numerous flavonoid metal complexes mentioned in this paper could be the future treatment against various cancerous diseases.

Electron Structure of α‐, β‐Te2MoO7 and Photocatalytic Decomposition of Antibiotics

AbstractTwo modifications of Te2MoO7 oxide have been prepared by different synthetic methods. The crystal structure and composition have been studied by X‐ray diffraction analysis and X‐ray microanalysis. The phase of α‐Te2MoO7 has been synthesized by solid‐state reaction from ammonium salts and characterized by monoclinic structure with P21/c. The β‐Te2MoO7 compound has been formed in hydrothermal conditions and has amorphous nature. The thermal behavior of β‐Te2MoO7 modification is characterized by the phase transition into α‐form, however after melting the amorphous state has restored. The electron structure has been investigated experimentally by X‐ray photoelectron spectroscopy and UV‐vis diffusion reflectance spectra and theoretically by approximation using atomic electronegativity. Despite the same composition, the band gap of β‐Te2MoO7 corresponds to visible light, whereas α‐Te2MoO7 adsorbs light in UV region. The both modifications are able to generate superoxide radicals in vacuum or air and hydroxyl radicals in water under irradiation. The HPLC‐MS analysis has shown the quite deep decomposition of dye and antibiotics by α‐Te2MoO7, whereas amorphous phase almost does not lead to any oxidation.

Evaluation of marine economic development demonstration zone policy on marine industrial structure optimization: a case study of Zhejiang, China

The marine economic development demonstration zone (MEDDZ) is the regional marine functional policy that assumes the significant tasks of innovation in the system and mechanism of the marine economy, optimization of the marine industrial structures, and the construction of marine ecological civilization. This paper constructs a panel database of 11 coastal provinces in China from 2006 to 2019, takes the Zhejiang Marine Economy Development Demonstration Zone Plan officially approved by the State Council of China in 2011 as a quasi-natural experiment, applies the synthetic control method (SCM) to evaluate the effect of implementation of the MEDDZ policy on marine industrial structure optimization in Zhejiang. The results show that: (1) The MEDDZ policy significantly promotes the structure optimization of the marine industry in Zhejiang and the existence of the policy lag phenomenon. (2) Based on the results of the robustness tests, we find that the fitted path of policy effects is better when the time of MEDDZ implementation is adjusted to 2012. (3) Government financial support and marine cargo capacity play a role in implementing the MEDDZ policy, positively affecting and optimizing the coastal marine industry’s structure. Therefore, we make some suggestions from the perspectives of strengthening the policy implementation process, focusing on the policy lag phenomenon, and broadening funding sources, thus enriching theoretical research on policies in the field of the marine industry and providing practical references for the development of other coastal demonstration zones.

Sulfur Modified Carbon-Based Single-Atom Catalysts for Electrocatalytic Reactions.

Efficient and sustainable energy development is a powerful tool for addressing the energy and environmental crises. Single-atom catalysts (SACs) have received high attention for their extremely high atom utilization efficiency and excellent catalytic activity, and have broad application prospects in energy development and chemical production. M-N4 is an active center model with clear catalytic activity, but its catalytic properties such as catalytic activity, selectivity, and durability need to be further improved. Adjustment of the coordination environment of the central metal by incorporating heteroatoms (e.g., sulfur) is an effective and feasible modification method. This paper describes the precise synthetic methods for introducing sulfur atoms into M-N4 and controlling whether they are directly coordinated with the central metal to form a specific coordination configuration, the application of sulfur-doped carbon-based single-atom catalysts in electrocatalytic reactions such as ORR, CO2RR, HER, OER, and other electrocatalytic reaction are systematically reviewed. Meanwhile, the effect of the tuning of the electronic structure and ligand configuration parameters of the active center due to doped sulfur atoms with the improvement of catalytic performance is introduced by combining different characterization and testing methods. Finally, several opinions on development of sulfur-doped carbon-based SACs are put forward.

Enantioselective Synthesis of Substituted Dihydropyrans by Organocatalyst-Mediated Domino Michael/Enolization/Acetalization Reactions

AbstractA highly enantioselective synthetic method for 3,4-trans-dihydropyrans was developed by the reaction of α-acyl-β-aryl-substituted acrylonitrile and aldehyde catalyzed by diphenylprolinol silyl ether. This is an asymmetric domino reaction via a catalytic Michael reaction/enolization/acetalization.

Current Developments in Emerging Lanthanide-Doped Persistent Luminescent Scintillators and Their Applications.

Lanthanide-doped scintillators have the ability to convert the absorbed X-ray irradiation into ultraviolet (UV), visible (Vis), or near-infrared (NIR) light. Lanthanide-doped scintillators with excellent persistent luminescence (PersL) are emerging as a new class of PersL materials recently. They have attracted great attention due to their unique "self-luminescence" characteristic and potential applications. In this review, we comb through and focus on current developments of lanthanide-doped persistent luminescent scintillators (PersLSs), including their PersL mechanism, synthetic methods, tuning of PersL properties (e. g. emission wavelength, intensity, and duration time), as well as their promising applications (e. g. information storage, encryption, anti-counterfeiting, bio-imaging, and photodynamic therapy). We hope this review will provide valuable guidance for the future development of PersLSs.

An Ultra-broadband Metallic Plasmonic Antenna for Ultrasensitive Molecular Fingerprint Identification.

Near-field enhanced mid-infrared light-matter interactions via metallic plasmonic antennae (PA) have attracted much attention but are inevitably limited by the detuning between their narrow band and the broad applied spectral range. Here, we develop a new low-temperature incubation synthetic method to acquire uniform Ag microparticles (MPs) with numerous hotspots. Their plasmonic band is remarkably extended by the plasmonic coupling of numerous hotspots and covers the entire mid-infrared range (400-4000 cm-1). Hence, the almost complete molecular fingerprint of 4-mercaptobenzonitrile was successfully probed for the first time via resonant surface-enhanced infrared absorption (rSEIRA), and the rSEIRA spectra of different essential amino acids were further detected and exhibit a high spectral identification degree assisted by machine learning. This work changes the inertia perception of "narrow band and large size but small hotspot area" of mid-infrared metallic PA and paves the way for the ultrasensitive mid-infrared optical sensing.

Recent Advances in Developing Radical Methods for the Synthesis of Aliphatic Sulfonyl Fluorides

Sulfonyl fluorides have widespread applications in many fields, including organic synthesis, chemical biology, drug discovery and materials science. In particular, in the past decade, a number of aliphatic sulfonyl fluorides have been identified showing various biological activities. These applications and appealing features of sulfonyl fluorides have brought about a significant advancement in developing synthetic methods to access sulfonyl fluorides. In this review, we will discuss the recent developments of radical approaches for the synthesis of aliphatic sulfonyl fluorides.

A synthetic strategy for the preparation of alkoxy‐functionalized bis‐1,2,4‐triazinyl‐2,6‐pyridines

AbstractHeteroaryl‐1,2,4‐triazine complexants are commonly utilized in separation science for the selective chelation of minor An from Ln in simulated high‐level waste. To facilitate access to relevant chemical entities for hypothesis‐driven inquiry toward improved separations performance, a synthetic method to construct various alkoxy‐complexant derivatives was required. In this work, a convergent synthetic strategy for the production of 3,3′‐ and 4,4′‐tetraalkoxy‐bis‐1,2,4‐triazinyl‐2,6‐pyridines from readily available starting materials via a dealkylation/alkylation/condensation approach is described. Synthetic method development, substrate scope, preliminary solubility, and hydrolytic stability data in various process‐relevant diluents are reported herein.

Tetrafluoroethylation of Electron‐Rich Alkenyl Iodides Enabled by in situ Generation of Solvent‐Stabilized “Ligandless” CuCF2CF2H

AbstractIn this study, we have developed a metal‐mediated synthetic method for incorporating the 1,1,2,2‐tetrafluoroethyl (CF2CF2H) motif into unactivated, electron‐rich alkenyl iodides using cross‐coupling reactions. We discovered that the stable Cu(CF2CF2H)(PPh2Me)3 complex, while unreactive with these substrates, serves as a P‐ligated reservoir for the formation of solvent‐stabilized “ligandless” and reactive CuCF2CF2H species. This transformation occurs upon addition of CuBr, which partially scavenges the P‐ligand in the form of CuBr(PPh2Me)3. The resulting in situ generated solvent stabilized “ligandless” system significantly enhances the reactivity of the complex, particularly towards challenging electron‐rich substrates. This advancement enables the synthesis of HCF2CF2‐glycals, as well as nucleosides/nucleobases and arenes.

Recent Advances on the Chemistry of Transition Metal Complexes with Monoanionic Bidentate Silyl Ligands.

The chemistry of transition-metal (TM) complexes with monoanionic bidentate (κ2-L,Si) silyl ligands has considerably grown in recent years. This work summarizes the advances in the chemistry of TM-(κ2-L,Si) complexes (L = N-heterocycle, phosphine, N-heterocyclic carbene, thioether, ester, silylether and tetrylene). The most common synthetic method has been the oxidative addition of the Si-H bond to the metal center assisted by the coordination of L. The metal-silyl bond distances in TM-(κ2-L,Si) complexes are in the range of metal-silyl bond distances. TM-(κ2-L,Si) complexes have proven to be effective catalysts for hydrosilylation and/or hydrogenation of unsaturated molecules among other processes.

Evaluating Firearm Violence After New Jersey’s Cash Bail Reform

Reducing the pretrial detention population has been a cornerstone of movements to end mass incarceration. Across many US cities, there are ongoing public debates on policies that would end pretrial detention due to the inability to afford bail, with some raising concerns that doing so would increase community violence. To evaluate changes in firearm violence after New Jersey's 2017 bail reform policy that eliminated financial barriers to avoiding pretrial detention. This case-control study used synthetic control methods to examine changes in firearm mortality and combined fatal and nonfatal shootings in New Jersey (2014-2019). New Jersey was chosen because it was one of the first states to systematically implement cash bail reform. Outcomes in New Jersey were compared with a weighted combination of 36 states that did not implement any kind of reform to pretrial detention during the study period. Data were analyzed from April 2023 to March 2024. Implementation of New Jersey's cash bail reform law in 2017. Quarterly rates of fatal and nonfatal firearm assault injuries and firearm self-harm injuries per 100 000 people. Although New Jersey's pretrial detention population dramatically decreased under bail reform, the study did not find evidence of increases in overall firearm mortality (average treatment effect on the treated, -0.26 deaths per 100 000) or gun violence (average treatment effect on the treated, -0.24 deaths per 100 000), or within racialized groups during the postpolicy period. Incarceration and gun violence are major public health problems impacting racially and economically marginalized groups. Cash bail reform may be an important tool for reducing pretrial detention and advancing health equity without exacerbating community violence.

Click Chemistry: Reaction Rates and Their Suitability for Biomedical Applications.

Click chemistry has become a commonly used synthetic method due to the simplicity, efficiency, and high selectivity of this class of chemical reactions. Since their initial discovery, further click chemistry methods have been identified and added to the toolbox of click chemistry reactions for biomedical applications. However, selecting the most suitable reaction for a specific application is often challenging, as multiple factors must be considered, including selectivity, reactivity, biocompatibility, and stability. Thus, this review provides an overview of the benefits and limitations of well-established click chemistry reactions with a particular focus on the importance of considering reaction rates, an often overlooked criterion with little available guidance. The importance of understanding each click chemistry reaction beyond simply the reaction speed is discussed comprehensively with reference to recent biomedical research which utilized click chemistry. This review aims to provide a practical resource for researchers to guide the selection of click chemistry classes for different biomedical applications.

A review on pyrimidine‐based derivatives: Synthesis and their biological application

AbstractPyrimidine‐based derivatives have attracted a lot of interest in heterocyclic chemistry due to its versatile structure and diverse biological activities. This study provides a comprehensive overview of synthetic strategy of different pyrimidine ring and highlights their biological importance. In this article, we start off by going through the fundamental procedures for the synthesis of pyrimidine scaffolds, including both conventional and contemporary synthetic techniques. These works cover a range of therapeutic domains, such as effects that are anticancer, antibacterial, antiviral, anti‐inflammatory, antioxidant, antimalarial, and so on. Moreover, we have summarized with a discussion of future prospects and challenges in the field of pyrimidine heterocyclic chemistry. This thorough review is a significant resource for researchers in medicinal chemistry and related fields since it offers insightful information about the synthetic methods and biological applications of pyrimidine‐based derivatives.

Did private election administration funding advantage Democrats in 2020?

Private donors contributed more than $350 million to local election officials to support the administration of the 2020 election. Supporters argue these grants were neutral and necessary to maintain normal election operations during the pandemic, while critics worry these grants mostly went to Democratic strongholds and tilted election outcomes. How much did these grants shape the 2020 presidential election? To answer this question, we collect administrative data on private election administration grants and election outcomes. We then use advances in synthetic control methods to compare presidential election results and turnout in counties that received grants to counties with similar election results and turnout before 2020. While Democratic counties were more likely to apply for a grant, we find that the grants did not have a noticeable effect on the presidential election. Our estimates of the average effect on Democratic vote share range from 0.03 to 0.36 percentage points. Our estimates of the average effect of receiving a grant on turnout range from 0.03 to 0.14 percentage points. Across specifications, our 95% CIs typically include negative effects and all fail to include effects on Democratic vote share larger than 0.58 percentage points and effects on turnout larger than 0.40 percentage points. We characterize the magnitude of our effects by asking how large they are compared to the margin by which Biden won the 2020 election. In simple bench-marking exercises, we find that the effects of the grants were likely too small to have changed the outcome of the 2020 presidential election.

2‐Vinylaniline in the synthesis of heterocycles: Recent advances

Abstract2‐Vinylanilines are readily accessible substrates, which are undoubtedly one of the best candidates for the construction of diversely nitrogen‐containing heterocyclic compounds. Owing to the amine and alkenyl groups in their structures, these frameworks offer a facile, direct, and selective synthetic method. This review describes various cyclization reactions involving 2‐vinylanilines catalyzed by transition metals, or under metal‐free conditions.

Efectos olvidados: herramienta de análisis en la producción de PYMES Industriales de Cuenca

Small and medium-sized enterprises (SMEs) are the support for the promotion of development through the production and sale of their products. The aspect to be studied is the decrease in production, a consequence of the slow economic reactivation of these firms since the events related to the pandemic in the year 2020. The research seeks to recognize the measures and consequences in order to address and solve the identified problem. This will be achieved through the application of the Theory of Neglected Effects (TEO), which are not always captured by the scholars of the subject, to reduce hesitations and decide in a more accurate way. Methodologically, the research has a mixed descriptive approach, where the synthetic analytical method is implemented. Surveys were applied to subjects with production expertise, using the endecadary scale and fuzzy logic to develop a square matrix of forgotten effects, thus identifying the underlying variable. The results reveal changes in the form of behavior from synergy, which positively impacts increased productivity by decreasing costs. Finally, by applying the guidelines of the scholars and obtaining a matrix that relates qualitative variables, based on cause and effect links, a criterion is obtained that facilitates decisions and the possibility for companies to arrange production increases for the fortune of the company.

Government Religious Discrimination, Support of Religion, and Muslim Minority-Related Societal Violence in Western Democracies

Does government-based religious discrimination against religious minorities and government support of majority religion affect religiously motivated societal violence between minorities and majority religious groups in Western democracies? Analyzing Muslim minorities, this study tries to answer the question by looking specifically at the religious violence perpetrated by and against these minorities in the West. Using a novel cross-national time-series data on 25 Western countries disaggregated by victim and perpetrator groups, this paper finds that while discrimination contributes to a country encountering religiously driven societal violence perpetrated by both Muslim and majority religious groups, government support for majority religion seems to pose no security threat. Furthermore, a case study analysis of the UK employing the synthetic control method corroborates the results of the cross-country analysis. The findings have important policy implications for counter-strategies against both Islamic and right-wing violent extremism in the West.