Triazole Ring Research Articles

Computer prediction of toxicity of new S-alkyl derivatives of 1,2,4-triazole

1,2,4-Triazole derivatives are of researchers’ significant interest due to their diverse biological properties, such as antimicrobial, anti-inflammatory, anticancer, and antioxidant activities. The integration of a 2-bromo-4-fluorophenyl fragment into the triazole structure can significantly enhance these activities. However, the evaluation of the toxicity of such compounds remains a critically important aspect for their practical application. To reduce the time and cost of experimental studies, QSAR (Quantitative Structure-Activity Relationship) methods are actively used, allowing the prediction of toxicity based on the molecular structure of compounds. Aim of the study. To assess the toxicity of new S-derivatives of 5-(2-bromo-4-fluorophenyl)-4-R-1,2,4-triazol-3-thiols using the QSAR method, specifically to predict acute toxicity parameters (LD50), and to determine the influence of different (length) radicals on the toxicity of these compounds. Materials and methods. The objects of the virtual study were derivatives of 5-(2-bromo-4-fluorophenyl)-4-ethyl-1,2,4-triazol-3-thiols. They were evaluated at the Department of Toxicological and Inorganic Chemistry of the Zaporizhzhia State Medical and Pharmaceutical University. The toxicity assessment was conducted using the nearest neighbor method via the Toxicity Estimation Software Tool (TEST). The prediction of the lethal dose (LD50) for rats was based on the structural similarity of the studied compounds with known substances, for which experimental toxicity data are available. Results. The conducted QSAR analysis demonstrated that structural changes in S-derivatives of 5-(2-bromo-4-fluorophenyl)-4-ethyl-1,2,4-triazol-3-thiols significantly affect the predicted toxicity. The primary factor influencing the changes in LD50 values is the variation of radicals at the 5th position of the triazole ring. Conclusions. The results of the study showed, that the toxicity of new S-alkyl derivatives of triazol-3-thiols depends on the type of alkyl substituent. Compounds with propyl to heptyl fragments exhibit increased toxicity, while derivatives with thiol, octyl, nonyl, and decyl residues are characterized by lower toxicity.

Syntheses, Structures, and Photocatalytic and Sonocatalytic Degradations of Methyl Blue of Cu(II) and Mn(II) Coordination Polymers Based on Tri(triazole) and Dicarboxylate Ligands

Cu(II) and Mn(II) coordination polymers [Cu(ttpa)(sub)]n (Cuttpa or 1) and {[Mn2(ttpa)2(nip)2(H2O)2]·3H2O}n (Mnttpa or 2) (ttpa = tris(4-(1,2,4-triazol-1-yl)phenyl)amine, H2sub = suberic acid, nip = 5-nitroisophthalicate) were hydrothermally prepared and the structures were characterized. Cuttpa exhibited a 2D (4,4) network based on [Cu2(COO)4] dimers with upper and lower dangled ttpa ligands and a 2D → 3D polythreaded network. Mnttpa showed a 2D (4,4) network with dangled uncoordinated triazole rings from ttpa ligands and nitro groups from nip2− ligands and a 2D → 3D polythreaded network. Eg data of Cuttpa and Mnttpa were 1.88 eV and 2.11 eV. Cuttpa and Mnttpa exhibited good catalytic activity for the decomposition of methyl blue (MB) under visible light and supersound irradiation. The decomposition mechanism using Cuttpa was explored. The holes (h+) and •OH hydroxyl radicals played the main roles, and the •O2− superoxide radicals played certain auxiliary roles in the decomposition of MB within the Cuttpa catalyst.

Aniline Derivatives Containing 1-Substituted 1,2,3-Triazole System as Potential Drug Candidates: Pharmacokinetic Profile Prediction, Lipophilicity Analysis Using Experimental and In Silico Studies

Background: The triazole ring is an attractive structural unit in medicinal chemistry, and chemical compounds containing this type of system in their structure exhibit a wide spectrum of biological activity. They are used in the development of new pharmaceuticals. One of the basic parameters considered in the initial phase of designing potential drugs is lipophilicity, which affects the bioavailability and pharmacokinetics of drugs. Methods: The study aimed to assess the lipophilicity of fifteen new triazole derivatives of aniline using reversed phase thin layer chromatography (RP-TLC) and free web servers. Based on in silico methods, the drug similarity and pharmacokinetic profile (ADMET) of synthesized molecules were assessed. Results: A relationship was observed between the structure of the title compound, including the position of substitution in the aniline ring, and the experimental values of lipophilicity parameters (logPTLC). Most of the algorithms used to determine theoretical logP values showed less sensitivity to structural differences of the tested molecules. All obtained derivatives satisfy the drug similarity rules formulated by Lipinski, Ghose and Veber. Moreover, in silico analysis of the ADME profile showed favorable values of parameters related to absorption.

Dual metal centers within a water-stable Co/Ni bimetallic metal-triazolate framework contribute to durable photocatalysis for water treatment.

Bimetallic metal-organic frameworks (MOFs) have been studied extensively in various fields, including photocatalytic and electrocatalytic applications. The enhanced catalytic activity is typically attributed to the synergistic effect of the two metals, often without further explanation. Here, we demonstrate a CoNi-bimetallic triazolate MOF with fixed metal occupancy within the MOF's secondary building unit. Due to the difference in electronegativity and so on, the charge redistribution between the two metal centers could be responsible for the enhanced photocatalytic activity. In addition, the metal(II)-triazolate MOFs we synthesized exhibit unique metal-N coordination and a strong bond between the metal center and triazole ring. Therefore, their crystal structure and high porosity are highly retained even after exposure to humid environments for several months or stirring in water for several days. Overall, the CoNi-bimetallic triazolate MOF combines the excellent water stability and high surface area of its two monometallic counterparts. It can be further tailored to yield the highest colloidal stability during photocatalytic water treatment. As a result, the dual metal centers within the bimetallic MOF, combined with boosted colloidal stability, demonstrate the highest reactive oxygen species generation and promising antibacterial performance compared to their Ni- or Co-based counterparts. These findings shed light on the future design of robust MOF-based photocatalysts, particularly bimetallic ones.

Synthesis of 2‐Aryl‐2H‐1,2,3‐triazoles via P(OMe)3‐Promoted Intramolecular Transannulation of 4‐Diazenylisoxazol‐5(4H)‐ones

AbstractTrimethyl phosphite promotes the synthesis of 2,4,5‐trisubstituted 2H‐1,2,3‐triazoles. The protocol developed affords a two‐step method towards triazoles from available reagents. 3,4‐Disubstituted isoxazolones are initially coupled with diazonium tetrafluoroborates. The subsequent reaction is triggered by a single electron transfer from the phosphite to the diazenylisoxazolone under heating or blue LED irradiation at room temperature. The radical anion cascade proceeds via a ring opening/decarboxylation/cyclization sequence. The synthesized triazoles show promising fluorescence in the region from 340 nm to 450 nm with a quantum yield up to 81.6%. The emission energy depends slightly on the substituent nature at the triazole carbon atoms. If an electron‐donor group is introduced into the N2 substituent of the triazole ring, it results in a bathochromic shift of the luminescence energy.

Synthesis of Alkyl/Aryloxymethyl Derivatives of 1,2,4-Triazole-3-Carboxamides and Their Biological Activities.

Ribavirin and its analogues exhibit an in vitro antiproliferative effect in cancer cells. In this work, we studied the biological activities of a number of alkyl/aryloxymethyl derivatives of ribavirin's aglycon-1,2,4-triazole-3-carboxamide. Alkyl/arylxymethyl derivatives of 1,2,4-triazole-3-carboxamide with substitutions at the fifth or first position of the triazole ring, were synthesized and their antiproliferative and antimicrobial effects were assessed. For both series, the presence of an antiproliferative effect was investigated, and 1-alkyl/aryloxymethyl derivatives were shown an antimicrobial potential against a Gram-positive bacteria Micrococcus luteus and Gram-negative bacterium Pseudomonas aeruginosa. The obtained results showed that the n-decyloxymethyl derivatives induced leukemia cell death at low micromolar concentrations. We confirmed that n-decyloxymethyl derivatives of ribavirin inhibited the cell cycle progression and induced an accumulation of leukemia cells in the subG1-phase. The molecular docking results suggest that alkyl/aryloxymethyl derivatives may act by inhibiting translation initiation, due to interference with eIF4E assembly. The outcome results revealed that active derivatives (1- or 5-n-decyloxymethyl-1,2,4-triazole-3-carboxamides) can be considered as a lead compound for anticancer treatments.

Specific and enzyme-free monitoring of propiconazole pesticide residues in vegetables with a portable nanozyme-based paper sensor

The nanozyme-based colorimetric sensor shows promise for rapid pesticide detection but struggles with non-specific enzyme inhibition. This study developed a portable paper-based sensor for detecting the propiconazole (PC) pesticide using Fe@PCN-224 nanocubes (NCs). Characterization confirmed the successful synthesis of Fe@PCN-224 NCs, which displayed peroxidase-like activity. The specific interaction between PC's triazole ring and the Fe active site inhibited their activity, enabling selective detection with a limit of 8 × 10−9 mol L−1 and a linear range of 0.03 × 10−6 to 0.90 × 10−6 mol L−1. Kinetic studies revealed a Michaelis-Menten constants (Km) of 0.68 × 10−3 mol L−1 for TMB, indicating higher affinity in Fe@PCN-224 NCs. The electron paramagnetic resonance (EPR) analysis revealed the production of •OH, 1O2, O2•− during the catalytic reactions. By integrating smartphone technology, this portable sensor achieved recoveries from vegetable samples between 94.6 % and 109.2 %, demonstrating its potential as an accurate, cost-effective analytical tool for food safety and advancing nanozyme applications.

1,5-Disubstituted-1,2,3-Triazoles as GABA analogues: Synthesis, QSAR and biological evaluation as Pseudomonas fluorescens GABA-AT inhibitors

We report the synthesis of a new series of γ-aminobutyric acid (GABA) analogues as possible GABA-AT inhibitors, where the nitrogen at the Ƴ-position is contained in a 1,5-disubstituted-1,2,3-triazole ring system. The triazole ring system was assembled by the Ru(I)-catalyzed alkyne-azide 1,3-dipolar cycloaddition (RuACC) protocol. GABA-AT inhibition activity was predicted by means of a QSAR model that was constructed in this work. Different molecular descriptors families were employed for its construction, like steric type (Wap and PW5), solubility type (ΔPSA), and electronic type (ΔTriazole3). Additionally, a similarity analysis based on the electronic profile of 1,5-triazole and 1,4-triazole GABA analogues was done to support the QSAR predictions. Finally, the three best candidates were biologically tested as Pseudomonas fluorescens GABA-AT inhibitors showing an inhibition percent compared to FDA approved inhibitors.

Crystal structure, Hirshfeld surface analysis, and calculations of inter-molecular inter-action energies and energy frameworks of 1-[(1-hexyl-1H-1,2,3-triazol-4-yl)meth-yl]-3-(1-methyl-ethen-yl)-benzimidazol-2-one.

The benzimidazole moiety in the title mol-ecule, C19H25N5O, is almost planar and oriented nearly perpendicular to the triazole ring. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into a network structure. There are no π-π inter-actions present but two weak C-H⋯π(ring) inter-actions are observed. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (62.0%), H⋯C/C⋯H (16.1%), H⋯N/N⋯H (13.7%) and H⋯O/O⋯H (7.5%) inter-actions. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via the dispersion energy contributions in the title compound.

Application of infrared and nuclear magnetic resonance spectra in studying the bacterial efficacy of some oxazepane derivatives derived from hydrazones

This research included the utilisation of infrared and nuclear magnetic resonance spectra in studying and preparing new derivatives of the oxazepan ring by a series of reactions, where the triazole ring was prepared from the reaction of the carboxylic acid with carbothiohydrazide, and from the resulting reaction (triazole) with aqueous hydrazine. The latter was reacted with benzaldehyde compensators to prepare hydrazones, which is the basic intermediate for the preparation of the oxazepan ring. The hydrazones were reacted with succinic anhydride, and the validity of the structures was proven using infrared and nuclear magnetic resonance spectra of proton and carbon. Its biological activity has also been tested for two species of Gram-positive bacteria, Staphylococcus epidermidis and Gram-negative Klebsiella pneumoniae.

The Chemistry and Biological Effects of Fused 1,2,4-triazolo[4,3-c]pyrimidines and their Isomeric 1,2,4-triazolo[1,5-c]pyrimidines

Concerning polycyclic heterocyclic compounds, fused triazolopyrimidines and their substituted analogs have been studied recently from a chemical and biological point of view. Triazolopyrimidines have eight different positional isomers based on their structural arrangement and nitrogen atom positions. The present review concerns synthesizing 1,2,4- triazolo[4,3-c]pyrimidines and 1,2,4-triazolo[1,5-c]pyrimidines fused with a fivemembered ring containing one heteroatom. The 1,2,4-triazolo[4,3-c]pyrimidines can be prepared by closing the triazole ring on the 4-hydrazinopyrimidine ring, and the 1,2,4- triazolo[1,5-c]pyrimidines can be prepared by closing the triazole ring on the 4- iminopyrimidine-3-amine ring. The transformation of 1,2,4-triazolo[4,3-c]pyrimidine to the more thermodynamically stable isomer triazolo[1,5-c]pyrimidine derivatives via Dimroth rearrangement under different reaction conditions is also discussed. Moreover, the biological activity of both series is presented.

Pharmacological Evaluation of Bioisosterically Replaced and TriazoleTethered Derivatives for Anticancer Therapy

Cancer has been the cause of the highest number of deaths in the human population despite the development and advancement in treatment therapies. The toxicity, drug resistance, and side effects of the current medicaments and therapies have left the void for more research and development. One of the possibilities to fill this void is by incorporating Triazole moieties within existing anticancer pharmacophores to develop new hybrid drugs with less toxicity and more potency. The placement of nitrogen in the triazole ring has endowed its characterization of being integrated with anticancer pharmacophores via bioisosteric replacement, click chemistry and organocatalyzed approaches. This review paper emphasizes the discussions from articles published from the early 2000s to the current 2020s about the triazole-based derivatives used in anticancer therapy, elaborating more on their chemical structures, target receptors or enzymes, mechanism of action, structure-activity relationships, different triazole-derived hybrid drugs under clinical and nonclinical trials, and recent advancements toward developing more potent and less toxic anticancer agents.

Click Chemistry for the Generation of Combination of Triazole Core and Thioether Donor Site in Organosulfur Ligands: Applications of Metal Complexes in Catalysis.

During the last two decades, organosulfur compounds have been used in the field of transition metal catalysis. Some of such compounds are known for their ability to withstand their exposure to air and moisture. These compounds are very important ligands. They may be obtained using simple and smooth modular synthetic protocols which include nucleophilic substitution reactions. The development of click chemistry represents a new era of innovation. It is a lighthouse of reliable and efficient reactions. In recent past, click chemistry has also been applied for the synthesis of such organosulfur ligands specifically suited for the dynamic field of transition metal catalysis. In order to synthesize novel compounds containing sulfur and triazole ring, click chemistry is an advantageous methodology over other approaches. This article covers the general features and uses of this methodology for the development of catalytically active organosulfur compounds. The significant advances in the design of transition metal catalytic systems utilizing such ligands, their use in the catalysis of many chemical transformations are also covered in this article. Effort has also been made to present a comparative overview of the performances of such catalysts vis-à-vis the catalysts designed commonly used ligands. Catalytic performances have been discussed thoroughly in order to identify the impact of ligand architecture on efficacy of the catalyst. Effect of reaction conditions (such as time, temperature etc.) and mechanistic aspects have also been rationalized.

Manifesting the multi-stimuli-responsive behaviour of triazole-substituted triphenylamine.

The development of multi-stimuli-responsive (MSR) materials is a tempting yet intriguing challenge due to the absence of a defined design approach. In this study, we designed and synthesised two compounds based on triphenylamine, namely, TPA-Tz1 and TPA-Tz2. The photoluminescent investigations reveal the MSR behaviour of both compounds. TPA-Tz1 shows reversible mechanochromism with a blue-shifted emission due to changes in intermolecular interactions. Furthermore, both compounds exhibit solvatochromism in solvents of varying polarity. Detailed studies suggest that solvatochromism in TPA-Tz1 can be attributed to twisted intramolecular charge transfer (TICT), while in TPA-Tz2, it is due to intramolecular charge transfer (ICT). Additionally, both compounds display acidochromic properties in solution as well as in the solid state due to the protonation of the triazole ring. All changes in emissions are corroborated through theoretical calculations. The results provide insights into the intricate interplay of molecular interactions and structural rearrangements that contribute to the compound's multifaceted responsiveness.

Facile strategy for the synthesis of antimicrobial poly(vinyl chloride) functionalized with benzimidazole

AbstractSynthesizing antimicrobial materials is a viable approach to combating microbes and mitigating their detrimental consequences on public health and economic domains. Here, we aim to design and synthesize hybrid polymers composed of poly(vinyl chloride) (PVC) and benzimidazole derivatives, in addition to evaluating their antimicrobial efficacy. PVC was chemically functionalized affording 4 conjugates where the benzimidazole motif was incorporated indirectly into the PVC through a triazole ring combined with a short linker. This functionalized PVC was synthesized by employing Cu azide–alkyne cycloaddition (CuAAC) conditions (click chemistry). The second functionalized PVC was synthesized by a nucleophilic substitution reaction to give 5, which has a benzimidazole moiety attached directly to the PVC via a short spacer arm. The benzimidazole derivatives and the corresponding benzimidazole‐PVC conjugates were investigated by elemental analysis and spectroscopic techniques (IR, NMR, and MS) as needed, besides UV–vis spectroscopy, x‐ray diffraction (XRD), and scanning electron microscopy (SEM) and energy dispersive x‐ray spectroscopy (EDX) in the case of the polymeric conjugates. The SEM morphology demonstrated a change in the PVC surface after the modification, showing spongy structures. Furthermore, the chemical characterization using EDX revealed peaks representing C, O, and N, in addition to the characteristic Cl peaks. The benzimidazole derivatives and the corresponding functionalized PVC were evaluated as antimicrobial agents against a variety of Gram‐negative and Gram‐positive bacteria and fungi strains utilizing the well diffusion assay. The data revealed an improvement in the antimicrobial activity of the functionalized PVC (4) that contained triazolobenzimidazole against pathogenic Escherichia coli and S. typhimurium.Highlights Microbes have negative impact on public health and economic domains Synthesizing antimicrobial materials is a viable approach to combating microbes We herein synthesized PVC/benzimidazole hybrid polymers Functionalized PVC was synthesized and characterized by IR, NMR, SEM and EDX PVC/benzimidazole hybrids were evaluated as antimicrobial agents.

Cyclohexanediamine Triazole (CHDT) Functionalization Enables Labeling of Target Molecules with Al18F/68Ga/111In.

The Al18F-labeling approach offers a one-step access to radiofluorinated biomolecules by mimicking the labeling process for radiometals. Although these labeling conditions are considered to be mild compared to classic radiofluorinations, improvements of the chelating units have led to the discovery of (±)-H3RESCA, which allows Al18F-labeling already at ambient temperature. While the suitability of (±)-H3RESCA for functionalization and radiofluorination of proteins is well established, its use for small molecules or peptides is less explored. Herein, we advanced this acyclic pentadentate ligand by introducing an alkyne moiety for the late-stage functionalization of biomolecules via click chemistry. We show that in addition to Al18F-labeling, the cyclohexanediamine triazole (CHDT) moiety allows stable complexation of 68Ga and 111In. Three novel CHDT-functionalized PSMA inhibitors were synthesized and their Al18F-, 68Ga-, and 111In-labeled analogs were subjected to a detailed in vitro radiopharmacological characterization. Stability studies in vitro in human serum revealed among others a high kinetic inertness of all radiometal complexes. Furthermore, the Al18F-labeled PSMA ligands were characterized for their biodistribution in a LNCaP derived tumor xenograft mouse model by PET imaging. One radioligand, Al[18F]F-CHDT-PSMA-1, bearing a small azidoacetyl linker at the glutamate-urea-lysine motif, provided an in vivo performance comparable to that of [18F]PSMA-1007 but with even higher tumor-to-blood and tumor-to-muscle ratios at 120 min p.i. Overall, our results highlight the suitability of the novel CHDT moiety for functionalization and radiolabeling of small molecules or peptides with Al18F, 68Ga, and 111In and the triazole ring seems to entail favorable pharmacokinetic properties for molecular imaging purposes.

Triazole‐, piperazine‐, and DOPO‐containing eugenol‐based reactive flame retardant for unsaturated polyester resin

AbstractThe flammability of unsaturated polyester resins (UPRs) limits their applications. Herein, a reactive P‐ and N‐containing flame retardant (DPET) having triazole and piperazine rings is reported. The 9,10‐Dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐oxide (DOPO) was used to introduce P atoms, and eugenol was used to import reactive double bonds to DPET. Different ratios of DPET were mixed with a commercial UPR and the thermal, mechanical, optical, and flame retardancy properties were measured. The addition of 15% of DPET into neat UPR led to a decrease in the water contact angle from 70° ± 2 to 61° ± 2. The gel content values of the UPRs were found to change between 97.5% and 89%. The optical properties of the UPR were adversely affected by the incorporation of DPET. The modulus of the DPET‐containing UPRs increased with increasing amount of DPET and 15% of DPET‐containing UPR displayed a modulus value of 1784 ± 86 MPa. When 15% DPET was added to neat UPR, char yields were increased (from 5.6% to 16.6%). Limiting oxygen index (LOI) values increased with increasing amounts of DPET and reached up to 23.4%. Micro cone calorimeter (MCC) test results showed up to a 20.5% reduction in the peak heat release rate (PHRR) of the UPR when 15% DPET was added.

Theoretical study of two coumarin derivatives photosensitivity for possible use in photodynamic therapy

<p>The dynamism of cancer and its side effects related to different treatments are real questions for humankind to solve. Thus, this manuscript aims to explore the photochemical and photo-physical properties of two coumarin molecules due to their multiple biological and spectroscopic activities <sup>1</sup> in the framework of photodynamic therapy (PDT) as a photosensitizer (PS). For our aim fulfillment, quantum chemical methods such as DFT and TD-DFT at the B3LYP/6-31G(d,p) level were used in different media <sup>2</sup> to determine the parameters quoted above. The obtained results show that the solvent's nature influences the compounds' photosensitivity <sup>3</sup>. Thus, both compounds M1 and M2 are coumarins. M1 and M2 belong to benzocoumarin and simple coumarin families, respectively. In other words, the coumarin ring of M1 is attached to a benzene ring. Apart from this difference, compound M1 contains a triazol ring, and compound M2 contains an oxadiazol ring. These compounds produce charged radicals.</p><p>Moreover, compound M1 presents the lowest values of VIP and the energy of the excited state E<sub>T</sub> necessary for producing charged radicals. Therefore, it is assumed to be the most photosensitive, and this photosensitivity is more accentuated in polar solvents. In sum, studied coumarins, in addition to being used in chemotherapy, can also be used in PDT as PS. However, the theoretical improvement of the studied parameters would be a significant advance for the experimenter.</p>

Superior Enhancement in Mechanical Properties of Polyurethane‐Based Multifunctional GAP Partially Grafted with Fluorinated Polyether via Catalyst‐Free Click Reaction

AbstractDifunctional glycidyl azide polymer (GAP) is an energetic binder promising for propellant formulations. The multifunctional fluorine‐containing GAP has been synthesized to enhance its mechanical properties. This work outlined multifunctional GAP partially grafted with 1,2,3‐triazole‐5‐(α‐hydroxyl)‐fluorinated polyether (GAP‐g‐3F) synthesized by thermal and catalyst‐free azide‐alkyne cycloaddition reaction, in which the azide groups were from GAP and electron‐deficient alkynes from β‐propargyl‐α‐hydroxyl poly (tri‐fluoropropane glycidyl ether) (PHP3F). PHP3F was synthesized via the typical cationic ring‐opening polymerization of 2‐((2,2,2‐trifluoroethoxy) methyl) oxirane and propargyl alcohol as the initiator. The chemical structures, molecular weight, and thermal properties were characterized by FTIR, NMR, GPC, DSC, and TGA, respectively. HNMR results showed that 8 % of total azide groups in GAP were grafted. GAP‐g‐3F had a slightly higher glass transition temperature than that of GAP. The results of TGA showed that GAP‐g‐3F had suitable thermal decomposition resistance up to 200 °C. The thermal properties, mechanical properties, cross‐linking network structures, and microstructures of the polyurethane networks cured with hexamethylene diisocyanate trimer as a crosslinking agent were determined and compared by TGA, universal tensile test, swelling measurement, and SEM, respectively. The initial decomposition temperature of GAP‐g‐3F‐based polyurethane networks (GAP‐g‐3F‐PU) was around 220 °C, thus meeting the requirements for propellants. In addition, GAP‐g‐3F‐PU exhibited superior mechanical properties, showing an almost twelvefold increase in tensile strength to 16.9 MPa compared with difunctional GAP‐PU with 1.4 MPa tensile strength. The results of the swelling measurement revealed that the GAP‐g‐3F‐PU sample showed a higher crosslinking density in comparison to the GAP‐PU sample. SEM results indicated that the multifunctional fluorine‐containing GAP could enhance compatibility between the soft and hard segments of polyurethanes, leading to a decrease in their separation degree. This finding showed that the synthesis of a multifunctional GAP partially grafted with fluorinated polyether via a triazole ring may be a promising solution to decrease the separation degree increase of PUs, thereby improving the mechanical properties.

Development of a chiral TPr# ligand and application for asymmetric palladium and copper catalysis

We report the design and synthesis of chiral triazolylidene-metal complexes with bulky substituents at the triazole ring. The palladium complex could be applied to the asymmetric Suzuki-Miyaura cross coupling reaction of 1-naphthaleneboronic acid and 1-bromo-2-methoxynaphthalene to afford the coupling product with good enantioselectivity. The reaction was found to proceed even at 10 mol ppm catalyst loading, leading to high turnover numbers of up to 2300. The chiral triazolylidene-copper complex was employed as an asymmetric catalyst for the borylation of methyl cinnamate to provide the borylated product with good enantioselectivity.