Reaction Patterns Research Articles

C−H Bond Activation Facilitated by Nickel(II) Complexes Having Mighty Claws

AbstractStreamline synthesis of cyclic alcohols has been an enduring goal in synthetic chemistry. In this regard, a series of aminoquinoline‐based pincer ligands (L1(H)=2‐(dimethylamino)‐N‐(quinolin‐8‐yl)acetamide, L2(H)=2‐(diethylamino)‐N‐(quinoline‐8‐yl)acetamide, L3(H)=2‐(dipropylamino)‐N‐(quinoline‐8‐yl)acetamide and L4(H)=2‐(dibutylamino)‐N‐(quinolin‐8‐yl)acetamide)) and corresponding nickel(II) complexes of the type [Ni(L)Cl] (1–4) were synthesized and characterized using modern analytical techniques. Further, the catalytic activity of 1–4 was investigated for the oxidation of cyclohexane in the presence of different oxidants. All the catalysts showed substantial activity in the presence of m‐CPBA as the oxidant in DCM‐CH3CN (v/v, 3 : 1) solvent mixture at 60 ° C to yield cyclohexanol as the major product and cyclohexanone and caprolactone as the minor products. Under the optimised reaction conditions, catalytic activity was in the order 1 (936)>2 (892)>3 (835)>4 (785), which can be rationalized by the steric‐electronic properties of the respective ligands. Notably, with catalyst 1, we could achieve the highest TON (936) reported so far for cyclohexane oxidation using nickel(II) complexes having square planar geometry. The best catalyst, 1 was further used for the oxidation of other cycloalkanes and showed appreciable activity. The formation of chlorinated products in the reaction and product distribution pattern revealed that the oxidation is mediated majorly by 3‐chlorobenzoyloxy radical.

2,3-Arylacylation of allenes through synergetic catalysis of palladium and N-heterocyclic carbene

An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis. It's the first time that allene was introduced into transition metal and NHC synergetic catalysis, which demonstrated a versatile three-component reaction pattern, thus enabling two C-C bonds forged regioselectively in the reaction. The important reaction intermediates were successfully captured and characterized by HRMS analysis, and the migrative insertion of allene to the Ph-Pd species was identified as the reaction rate-limiting step by kinetic experiments.

Evolution of political traditions and mentality of Ukrainian society

The article analyzes the processes of formation and evolution of political traditions and mentality of Ukrainian society, their impact on public sentiment and political decision-making, which can be both supportive and legitimate foundation, as well as rejection and denial, and an obstacle to political and economic development. Due to the peculiarities of its historical development and geopolitical location, Ukraine has strong ties with European countries and shares similar values, and is geographically part of Europe. Ukrainian political traditions are based on support for democratic principles and freedoms, rejection of dictatorial authoritarian practices, the ability of Ukrainian society to self-organize and build effective horizontal ties, and individualism. Ukrainians, like Europeans, consider the dignity of the human person as a fundamental value, and violence as unacceptable and humiliating. During national revolutions and in times of war, Ukrainians bravely defend the Motherland, protecting their freedom even at the cost of their lives. These fundamental features of the Ukrainian political mentality contributed to the formation of the Ukrainian political nation, and in combination with Cossack military traditions, the experience of the Ukrainian Insurgent Army and a number of patriotic organizations, they influence the heroic military confrontation with Russia today. However, the long stay of Ukrainian lands as part of other state entities, the imposition of different models of seeing the world, values, beliefs, the extermination of the political elite and patriotic activists and their families, etc. also reflected in the political traditions, moods, preferences, patterns of behavioral reactions of Ukrainian society. Especially destructive was the influence of Russian state entities, the period of being part of the USSR, which shaped the consciousness of homo soveticus – a cog in a totalitarian state system with limited rights and opportunities.

Chromium Complexes with Benzanellated N-Heterocyclic Phosphenium Ligands-Synthesis, Reactivity and Application in Catalytic CO2 Reduction.

A chromium complex carrying two benzanellated N-heterocyclic phosphenium (bzNHP) ligands was prepared by a salt metathesis approach. Spectroscopic studies suggest that the anellation enhances the π-acceptor ability of the NHP-units, which is confirmed by the facile electrochemical reduction of the complex to a spectroscopically characterized radical anion. Co-photolysis with H2 allowed extensive conversion into a σ-H2-complex, which shows a diverse reactivity towards donors and isomerizes under H-H bond fission and shift of a hydride to a P-ligand. The product carrying phosphenium, phosphine and hydride ligands was also synthesized independently and reacts reversibly with CO and MeCN to yield bis-phosphine complexes under concomitant Cr-to-P-shift of a hydride. In contrast, CO2 was not only bound but reduced to give an isolable formato complex, which reacted with ammonia borane under partial recovery of the metal hydride and production of formate. Further elaboration of the reactions of the chromium complexes with CO2 and NH3BH3 allowed to demonstrate the feasibility of a Cr-catalyzed transfer hydrogenation of CO2 to methanol. The various complexes described were characterized spectroscopically and in several cases by XRD studies. Further insights in reactivity patterns were provided through (spectro)electrochemical studies and DFT calculations.

Impact of ring size on the C[sbnd]H activation reactivity of iron(IV)–oxo complexes: A computational study with TMC macrocycles

Here, a DFT investigation has been presented to demonstrate the relevance of the macrocyclic ligand ring size of the high-valent Fe(IV)O complex-catalyzed CH activation process. A nonheme iron-oxo compound bound with extensively studied macrocycle tetramethylcyclam (TMC) with varying ring size measures in terms of n = 12, 13, 14, 15, and 16 in [Fe(IV)O(n-TMC)(CH3CN)]2+ has been considered as the oxidant and dihydroanthracene as the general substrate. Counterions, as always, have been considered to avoid the self-interaction error in these DFT calculations. Computations were carried out to determine the effect of the axial ligand, acetonitrile, on the CH activation reactivity. It has been discovered that the complexes without axial ligands turned out to be more reactive compared to their axially coordinated counterparts. The most intriguing finding, however, has been that reactivity increased steadily with ring size increments, giving us the trend 12 < 13 < 14 < 15 < 16. Behind this typical pattern of reactivity, several factors played a role, including the energy of the electron acceptor orbital, which sequentially decreases, and the distortion energy to achieve the transition state, which also decreases as we move on from n = 12 to 16. The triplet-quintet energy difference of the oxidants also has a part to play, as it decreases with increased ring size, with the quintet becoming more and more dominant. The current studies have also been able to corroborate the experimental data that was published regarding Fe(IV)O(13-TMC) (without axial syn form) having a higher CH activation reactivity than Fe(IV)O(14-TMC) (with axial anti form). On the whole, this computational exploration gives us a reactivity pattern based on the ring size commutes and can lead to successful experimental results if pursued based on this reaction.

Self-blame, posttraumatic stress, and cardiovascular reactivity among sexual trauma survivors.

Although trauma is closely linked with hyperarousal and cardiovascular health, little research has examined the effects of posttraumatic stress symptoms (PTSS) on cardiovascular reactivity to trauma reminders among sexual trauma survivors. One type of negative appraisal after trauma, self-blame, is common after sexual trauma, but its relation to cardiovascular reactivity is unknown. The present study aimed to examine the influence of both PTSS and self-blame on blood pressure and heart rate (HR) reactivity to a trauma reminder. Cardiovascular reactivity was measured before, during, and after a laboratory-based sexual trauma reminder among 72 young adult women who have experienced sexual trauma. Higher PTSS predicted lower diastolic blood pressure (DBP) reactivity during the trauma reminder. Higher levels of self-blame predicted higher HR and systolic blood pressure (SBP) reactivity during and after the trauma reminder. Overall, these findings suggest that survivors of sexual trauma with higher levels of PTSS experience a blunting reaction of DBP when exposed to trauma reminders, as opposed to a more typical cardiovascular stress reaction that may elevate and then extinguish to baseline levels. Meanwhile, individuals with higher levels of self-blame have heightened cardiovascular SBP and HR responses during trauma reminders that do not return to baseline levels, perhaps due to self-blame leading individuals to be more 'on guard' to prevent future threats. Longitudinal studies are needed to explore the potential long-term cardiovascular impacts of heightened self-blame and PTSS and their associated cardiovascular reactivity patterns.

Near-infrared light-driven biomass conversion.

Current photocatalytic technologies mainly rely on the input of high-energy ultraviolet-visible (UV-vis) light to obtain the desired excited states with adequate energy to drive redox reactions, precluding the use of low-energy near-infrared (NIR) light that occupies ~50% of the solar spectrum. Here, we report the efficient utilization of NIR light by coupling the low-energy NIR photons with reactive biomass conversion. A unique mechanism of photothermally synergistic photocatalysis was revealed for the selective biomass conversion under NIR light. Using biomass-derived 5-hydroxymethylfurfural (HMF) conversion as a model reaction, it was found that NIR and UV-vis light featured markedly different reaction patterns. 5-Formyl-2-furancarboxylic acid (FFCA) was almost exclusively produced under NIR light, whereas UV-vis light favored the formation of 2,5-diformylfuran (DFF) as the major product. This work provides a paradigm for sustainable and selective chemical synthesis using the Earth's abundant resources, sunlight and biomass.

Assessment of pattern of adverse drug reactions with chemo-therapeutic drugs in a tertiary care hospital of Government Medical College Anantnag: a prospective observational study

Assessment of pattern of adverse drug reactions with chemo-therapeutic drugs in a tertiary care hospital of Government Medical College Anantnag: a prospective observational study

Cascade C-H Activation and Two C-C Bond Forming in Reaction of Azalutetacyclopentadiene with 2-Methylbenzonitriles.

Azametallacyclopentadienes are an important class of metallacycles as the key intermediates in metal-promoted or catalyzed carbon-carbon coupling reaction of nitriles and alkynes. Rare-earth azametallacyclopentadienes have shown various reactivity toward nitriles, depending on the substituents of nitriles. The reaction of azalutetacyclopentadienes toward 2-methylbenzonitriles has been investigated in this work, which selectively affords the fused 7-5-6-membered azalutetacycles as products. Computational studies reveal that the reaction of azalutetacyclopentadienes toward 2-methylbenzonitriles selectively initiates with the remote activation of the benzylic C-H bond by the Lu-N bond, followed by the intramolecular nucleophilic attack from the deprotonated benzylic carbon to form a C-C bond. Subsequently, the high ring strain promoted the generation of the uncoordinated carbanion dissociated from the lutetium center, which then undergoes intramolecular nucleophilic attack toward C=N triple bond to give the final product containing fused 7-5-6-membered azalutetacycle. This work not only achieves highly selective three-step cascade reaction to form a unique class of rare-earth metallacycle, but also provides a new idea for the transformation of unsaturated substrates with C-H bonds that can be activated.

Detecção de Reações Adversas a Medicamentos em pacientes hospitalizados: uma abordagem de análise em rede

Objective: We aimed to investigate whether network analysis can be used to estimate patterns of Adverse Drug Reactions and drugs involved. Methods: Patients admitted from 18 years of age or older, hospitalized for more than 24 hours, and using at least one drug during hospitalization were included. Results: 8060 patients were observed, and 358 cases of Adverse Drug Reactions were identified (4.43%). The network graph shows that the occurrence of hypotension induced by furosemide, spironolactone and enalapril is related to serum changes in potassium and the occurrence of renal failure. Centered around nausea and vomiting node, there is a great variety of drugs from different classes involved with this Adverse Drug Reaction and without other connections. Conclusion: Network analysis is a promising strategy for identifying patterns that correlate adverse reactions to drugs administered during hospitalization.

A Comparison of the Microbial Populations in a Culture-Dependent and a Culture-Independent Analysis of Industrial Water Samples

Culture-dependent and culture-independent microbiological methods are two approaches used to study microbial community composition. Culture-dependent methods have been the standard method used for many years but have limited utility with unculturable microorganisms. Culture-independent methods, including molecular techniques, enable direct analysis of microbial DNA without requiring cultivation. Both culture-dependent and -independent methods have roles in advancing our understanding of microbiology, and a combination of these approaches often yields a comprehensive depiction of the microbial diversity within a dynamic system. Bacterial activity reaction tests (BARTs) are a common culture-dependent test used to identify bacteria growing in industrial water samples. In this study, next-generation sequencing (NGS) was used to identify the taxa growing in BARTs and compared with the BART reaction patterns. Additionally, several water samples were analyzed by both BART and NGS analysis to determine whether the bacteria found in the water were also present in the BARTs. The results showed overall agreement between NGS and BARTs, though, in some cases, the most abundant taxa found in the water samples differed from those in the BARTs. This highlights the need for further study into the microbial community dynamics of culture-dependent tests to determine whether they are representative of the original sample.

Nickel complexes bearing quinoline derived NNS donor ligands as catalytic activators for N-alkylation of anilines with alcohols.

Herein, we have reported a new series of NNS-donor ligands coordinated Ni(II) complexes and utilized them as catalytic activator to synthesize N-alkylated aminesand 1,2-disubstituted benzimidazoles. Theseparate reaction of [C9H6N-NH-C(O)-CH2-S-Ar] [Ar = C6H5 (L1); C6H4Cl-4 (L2);C6H4Me-4 (L3) and C6H4-OMe-4 (L4)]with Ni(OAc)2 in methanol at 80°C for 3 hours resulted in octahedral nickel complexes [(L1-H)2Ni] (C1), [(L2-H)2Ni] (C2), [(L3-H)2Ni] (C3), and [(L4-H)2Ni] (C4), respectively. All compounds have been characterized by micro and spectroscopic analysis. The molecular structure of complexes C1-C3 has also been determined by single crystal X-ray diffraction data. The utility of complexes C1-C4 were evaluated for the N-alkylation of aniline with benzyl alcohols, and for 1,2-disubstituted benzimidazoles synthesis. The obtained results indicate that complex C1 showed better catalytic activity in both N-alkylation of amines with benzyl alcohols [catalyst loading: 2.0 mol%; Yield up to 92%], and for 1,2-disubstituted benzimidazoles derivatives [catalyst loading: 2.0 mol%; Yield up to 94%)]. The mechanistic studies suggested that the reaction works through hydrogen borrowing from benzyl alcohol and its subsequent utilization for in situ reduction of imine. The experimentally observed catalytic reactivity patterns of complexes C1-C4 have found in good agreement with the HOMO-LUMO energy gaps obtained by DFT analysis of corresponding complexes.

Temporality of online reactions to fictional characters’ death

In the digital era, online reactions to broadcast media are an important feature of audience engagement. Although central, the question of the temporality of audience online reactions has been understudied. We investigate this question by exploring the temporal patterns of online reactions to fictional characters’ deaths. More than 3,500 forum reactions to Game of Thrones characters’ deaths were collected over 5 years. Temporal patterns of reactions to expected deaths displayed more long-term patterns, while reactions to unexpected deaths displayed more spontaneous patterns. These results further our understanding of death reactions’ temporality in cyberspace, in a multimedia and transmedia storytelling context.

Corrosion resistance of aluminum against acid activation in 1.0 M HCl by symmetrical ball − type zinc phthalocyanine

The inhibition effect of symmetrical Ball − type Zinc Phthalocyanine on Aluminum in 1mol/L hydrochloric acid was analyzed by electrochemical techniques. A novel ball-type zinc phthalocyanine (Zn-Pc) inhibitor has been synthesized and verified utilizing FTIR, nuclear magnetic resonance (1H NMR and 13C NMR), MALDI-TOF MS, and absorption spectroscopy (UV-Vis). In addition, laser-induced breakdown and photoluminescence spectroscopy were employed for additional study. Weight loss technique was employed to investigate the corrosion inhibition effectiveness of the synthesized Zn-Pc on Aluminum in 1mol/L hydrochloric acid at the range of variation temperatures (293–333 K). The inhibition efficiency of Zn-Pc increased with higher concentrations of Zn-Pc and decreased as the temperature increased. Furthermore, Zn-Pc demonstrated outstanding outcomes, achieving 72.9% at a very low inhibitor concentration (0.4 mmol/L) at 298 K. The experimental data for Zn-Pc Aluminum in 1mol/L hydrochloric acid obeys the Langmuir adsorption isotherm. Moreover, the corrosion system’s thermodynamic parameters and activation energy were determined. Quantum chemical calculations applying the (DFT) Density Functional Theory method was conducted and applied in this study. These calculations played a pivotal role in elucidating molecular structures and reactivity patterns. Through DFT, numerous reactivity indicators were computed, providing valuable insights into the chemical behavior of the studied compounds. These indicators, such as frontier molecular orbitals, electron density, and molecular electrostatic potential, were subsequently correlated with experimental data.

Latent profiles of social reactions to sexual assault disclosure among bisexual women.

Bisexual women experience higher rates of sexual assault (SA) and posttrauma distress compared to monosexual women. We examined the patterns of reactions to SA disclosure (positive and two types of negative) and bisexual minority stress (antibisexual stigma from heterosexual and lesbian/gay people, internalized binegativity) experienced by young bisexual women who experienced adult SA. We also examined differences in assault-related experiences, posttraumatic stress disorder and depression symptoms, and hazardous drinking based on the identified patterns. The current sample was drawn from two parent samples of women and included survivors who had disclosed an adult SA: (a) n = 149 bisexual women (98% cisgender, ages 18-35, 87.9% White) recruited via Amazon's Mechanical Turk and (b) n = 81 cisgender bisexual women (ages 18-25, 84% White) recruited via online ads. Latent profile analyses and analyses of variance were conducted. Analyses identified four latent profiles characterized by: (a) low stigmatizing responses, (b) high negative SA disclosure reactions, (c) high antibisexual stigma, and (d) highest stigmatizing responses. The fourth profile had higher posttraumatic stress disorder and depression symptoms and hazardous drinking compared to the other profiles. Results suggest women in the profile characterized by highest negative reactions to SA disclosure and highest bisexual minority stress (antibisexual stigma and internalized binegativity) may experience greatest distress postassault. Results highlight the importance for researchers, policymakers, and clinicians to consider and address both SA-related and identity-related stigma among bisexual survivors. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Iron‐Catalyzed C−H Alkylation/Ring Opening with Vinylbenzofurans Enabled by Triazoles

AbstractWe report an unprecedented iron‐catalyzed C−H annulation using readily available 2‐vinylbenzofurans as the reaction pattern. The redox‐neutral strategy, based on cheap, non‐toxic, and earth‐abundant iron catalysts, exploits triazole assistance to promote a cascade C−H alkylation, benzofuran ring‐opening and insertion into a Fe−N bond, to form highly functionalized isoquinolones. Detailed mechanistic studies supported by DFT calculations fully disclosed the manifold of the iron catalysis.

Recent Advances in Gold-Catalyzed Transformations of Vinyldiazo Reagents

AbstractSince their discovery in 2011, gold-catalyzed transformations of vinyldiazo compounds have become an important synthetic tool, enabling the identification of new reaction patterns that have greatly expanded the versatility of these reagents. In this short review, we showcase the most relevant advances that have been made in this exciting area of research.1 Introduction2 Gold-Catalyzed Transformations of Vinyldiazo Compounds Involving Metal Carbene Intermediates2.1 Liu’s Seminal Work: Vinylogous Reactivity of Au(I) Vinyl Carbenes2.2 Gold-Catalyzed Reactions of Vinyldiazo Compounds with Alkenes2.3 Gold-Catalyzed Reactions of Vinyldiazo Compounds with Alkynes2.4 Gold-Catalyzed Reactions of Vinyldiazo Compounds with Allenes2.5 Gold-Catalyzed Reactions of Vinyldiazo Reagents with Aromatic Compounds2.6 Gold-Catalyzed Reactions of Vinyldiazo Compounds with Nitriles2.7 Gold-Catalyzed Diazo Cross-Couplings3 Gold-Catalyzed Transformations of Vinyldiazo Compounds That Do Not Involve Initial Dinitrogen Extrusion3.1 Gold-Catalyzed Formal [n+2] Cycloaddition Reactions through the Vinyl Moiety of Vinyldiazo Compounds3.2 Gold-Catalyzed Transformations of Vinyldiazo Compounds Involving Initial Activation of the Non-Diazo Reagent4 Conclusions

Iron-Catalyzed C-H Alkylation/Ring Opening with Vinylbenzofurans Enabled by Triazoles.

We report an unprecedented iron-catalyzed C-H annulation using readily available 2-vinylbenzofurans as the reaction pattern. The redox-neutral strategy, based on cheap, non-toxic, and earth-abundant iron catalysts, exploits triazole assistance to promote a cascade C-H alkylation, benzofuran ring-opening and insertion into a Fe-N bond, to form highly functionalized isoquinolones. Detailed mechanistic studies supported by DFT calculations fully disclosed the manifold of the iron catalysis.

O-034 Specific KIR gene profiles and recurrent implantation failure

Abstract Study question Is there a link between killer cell immunoglobulin-like receptors (KIRs) genes, haplotypes, or genotypes and recurrent implantation failure (RIF)? Summary answer The KIRAA1 genotype significantly increases the risk of RIF. The presence of the full-length receptor KIR2DS4norm in KIRAA haplotype patients is indicative of RIF development. What is known already KIRs are expressed by a subset of uterine natural killer cells (uNK cells). The KIRs family consists of 16 genes with high polymorphism that are divided into two main haplotypes: KIRAA and KIRBx. The KIRAA haplotype consists mostly of inhibitory KIRs and only one activating receptor, KIR2DS4, whose function is uncertain, whereas the Bx haplotype has a diverse gene composition, with a focus on activating receptor genes. The primary difference is in the balance of KIRs, which can activate or inhibit uNKcells’ ability to produce components required for embryo-implantation, and hence they are thought to being implicated in RIF. Study design, size, duration A three-year observational cohort research was conducted at a private infertility centre. A total of 82 patients were genotyped for activating or inhibiting KIR genes. The study included 60 ovarian normo-responders under the age of 40, with 28 women with repeated implantation failure serving as the study group and 32 as controls. Participants/materials, setting, methods DNA was extracted from blood samples of all participants, including RIF patients and controls. The 16 KIR genes were investigated utilizing PCR with Sequence-Specific Primer (SSP) technique. Individual KIR gene profiles, KIRAA and KIRBx haplotypes, and their unique genotypes were detected by software analyses of the collected data based on the reaction pattern when compared to patterns associated with described KIR gene sequences. All data were statistically analysed with the Fisher Exact Test. Main results and the role of chance The frequencies of the two main haplotypes, KIR AA and KIR Bx, were 28% and 72%, respectively. Patients with more inhibitory KIR genes (haplotype KIR AA) had a higher rate of RIF (60% vs 40% in controls; P = 0.2) than those with KIR Bx phenotypes (37.5% RIF vs 62.5% controls; p = 0.026). Further analysis of KIR AA revealed two genotypes: KIR AA 1 (31.82%) and KIR AA195 (68.18%). The KIR2DS4 locus in the full-length receptor (KIR2DS4-norm) was only expressed in KIR AA1. The distribution of RIF occurrences in the two different genotypes demonstrates a significant increase in the number of RIF in the possessors of KIR AA1 (75% vs 15%, p = 0.01), with no significant difference between the two groups in the KIR AA195. Limitations, reasons for caution The study encompasses small samples but the association strength was noticeably high, which confers the findings more confidence. Wider implications of the findings These findings imply that women with a high proportion of inhibited KIR genes (haplotype KIR AA) and KIR2DS4norm are more likely to develop RIF. Trial registration number NA

Mechanochemical Synthesis of α-halo Alkylboronic Esters.

α-halo alkylboronic esters, acting as ambiphilic synthons, play a pivotal role as versatile intermediates in fields like pharmaceutical science and organic chemistry. The sequential transformation of carbon-boron and carbon-halogen bonds into a broad range of carbon-X bonds allows for programmable bond formation, facilitating the incorporation of multiple substituents at a single position and streamlining the synthesis of complex molecules. Nevertheless, the synthetic potential of these compounds is constrained by limited reaction patterns. Additionally, the conventional methods often necessitate the use of bulk toxic solvents, exhibit sensitivity to air/moisture, rely on expensive metal catalysts, and involve extended reaction times. In this report, a ball milling technique is introduced that overcomes these limitations, enabling the external catalyst-free multicomponent coupling of aryl diazonium salts, alkenes, and simple metal halides. This approach offers a general and straightforward method for obtaining a diverse array of α-halo alkylboronic esters, thereby paving the way for the extensive utilization of these synthons in the synthesis of fine chemicals.