Position Of Substituents Research Articles

Styrylchromones: Biological Activities and Structure-Activity Relationship.

Styrylchromones (SC) are a group of oxygen-containing heterocyclic compounds, which are characterized by the attachment of a styryl group to the chromone core. SC can be found in nature or can be chemically synthesized in the laboratory. As their presence in nature is scarce, the synthetic origin is the most common. Two types of SC are known: 2-styrylchromones and 3-styrylchromones. However, 2-styrylchromones are the most common, being more commonly found in nature and which chemical synthesis is more commonly described. A wide variety of SC has been described in the literature, with different substituents in different positions, the majority of which are distributed on the A- and/or B-rings. Over the years, several biological activities have been attributed to SC. This work presents a comprehensive review of the biological activities attributed to SC and their structure-activity relationship, based in a published literature search, since 1989. The following biological activities are thoroughly revised and discussed in this review: antioxidant, antiallergic, antiviral, antibacterial, antifungal, anti-inflammatory and antitumoral, affinity and selectivity for A3 adenosine receptors, neuroprotective, and α-glucosidase inhibition. In general, SC are composed by a promising scaffold with great potential for the development of new drugs.

Electrodeposition of Manganese (III) Phthalocyanine/ Reduced Graphene Oxide for Asymmetric Supercapacitor Devices.

In this study, two novel tetra-substituted manganese (III) phthalocyanines bearing (9H-carbazol-2-yl)oxy groups on peripheral (1) or non-peripheral (2) positions were prepared and used for modification of reduced graphene oxide (rGO) by applying a simple one-step electrodeposition technique for the first time. The manganese (III) phthalocyanines (MnPcs) were electropolymerized and graphene oxide was electrochemically converted into reduced graphene oxide simultaneously. Subsequently, an rGO-MnPc hybrid structure was formed directly on the NiF electrode (substrate) via layer-by-layer assembly. Additionally, the effect of substituent position on the charge storage capacity of the prepared hybrid capacitive candidates was investigated. The fabricated hybrid electrodes exhibited remarkable electrochemical performance due to the combination of manganese (III) phthalocyanines and reduced graphene oxide. The NiF/rGO2-2 electrode exhibited the highest specific capacitance (512.4 F g-1) at 0.5 A g-1 and the remained specific capacitance was obtained 88.1 % after 5000 consecutive charge-discharge cycles. An asymmetric supercapacitor (ASC) was constructed from rGO2-2 as the positive electrode and rGO as the negative electrode with a working potential of 1.5 V. The as-prepared device delivered a specific energy of 17.4 Wh kg-1 at 350 W kg-1. Hence, manganese (III) phthalocyanine-reduced graphene oxide electrodes can be considered outstanding materials for energy storage applications in the future.

Construction of Spiro Systems from Tetrathiafulvalene Derivatives by a Pinacol‐like Rearrangement

An efficient and generalized pinacol‐like rearrangement of tetrathiafulvalene (TTF) derivatives has been achieved using 2, 2, 6, 6‐tetramethylpiperidine oxide (TEMPO) as a key reagent, in place of a traditional metal catalyst. Examination of numerous TTF derivatives demonstrates the reaction's exceptional tolerance to a variety of substituents, achieving an overall yield of up to 97%. The optimization of reaction conditions and evaluation of reaction applicability were achieved by varying factors such as the redox potential (E11/2) of the substrate molecule, substituent type, substituent position, number of substituents, and structural symmetry. Additionally, the reaction mechanism was explored using isotopic labeling, real‐time monitoring UV‐Vis absorption spectroscopy, and X‐ray diffraction (XRD) analysis. Specifically, TTF is oxidized to TTF+• by p‐toluenesulfonic acid (TsOH·H2O). TTF+• subsequently reacts with TEMPO and H2O to form a pinacol‐like intermediate, which undergoes a rearrangement to release a 2, 2, 6, 6‐tetramethylpiperidin‐1‐ol (TEMPOH) molecule, forming the rearranged product as a hydrogenated cation, this intermediate undergoes deprotonation, leading to the formation of the final spiro product. This investigation led to the identification of a class of reactions for the efficient conversion of TTF derivatives into their spiro products via pinacol‐like rearrangement reaction.

Emerging Thermosensitive Probes Based on Triamino-Phenazinium Dyes.

Temperature is an essential physical characteristic that influences all biological processes. Building on previous research on dialkylamino-functionalized rhodamine-based thermo-sensors, we investigate herein the thermosensitive properties of triamino-phenazinium dyes. Through a simple five-step synthetic route, we synthesized amino-phenazinium chromophores 6 and 7, featuring diethylamine substituents at different positions. A comparative analysis of optical properties and thermosensitivity was conducted on these compounds and an isomer, 5, in which butylamine moiety replaced the diethylamine group. The different emissive behaviors of the three fluorophores emphasize that not only the chemical nature but also the specific position of the alkylamine substituent play fundamental roles in the synthesis of highly emissive thermo-probes.

RP-HPLC Study of the Complexation of Acetamiprid, Imidacloprid and Carboxin Guest Molecules With Thiophosphorylated Calix [6] Arene in Dimethylformamide-Acetonitrile-Water Mobile Phase.

Reversed-phase high-performance liquid chromatography was used to study the host-guest complexation of thiophosphacalixarenes (TPC 1-3) with acetamiprid, imidacloprid and carboxin as guests. The Onyx Monolithic C 18 column (150 × 0.1mm) and Phenomenex® were used with UV detection at 254nm. The mobile phase consisted of dimethylformamide-acetonitrile-water. The association constant of the 1:1 guest-host complexes was determined from the relationship between the retention factor of the guest and concentration of the thiophosphacalix [6] arene host in the mobile phase. The stability constants are influenced by size, nature, position and quantity of substituents in the benzene ring of the calixarene skeleton. The detection limits for TPC 1, TPC 2 and TPC 3 are 0.95, 1.20 and 1.40μg/mL, while the quantification limits are 2.85, 3.60 and 4.20μg/mL for TPC 1, TPC 2 and TPC 3, respectively.

Flavonoids as potential SARS-CoV-2 main protease inhibitors: In vitro activity evaluation, molecular docking, 3D-QSAR investigation and synthesis

The damage to public health posed by the COVID-19 epidemic remains non-negligible, and research into highly effective antiviral drugs is key to addressing the epidemic. The main protease (Mpro) is critical for SARS-CoV-2 replication and acts as an effective target for drug development. To date, many flavonoid compounds have been reported to exhibit inhibition of Mpro, and flavonoid structures are informative for the development of new inhibitors. In the present study, we first evaluated the ability of 35 flavonoid compounds to bind Mpro and found that the hydrophobic interaction generated between the benzene ring and the residues may be the main source of binding force. The in vitro inhibitory activity of these compounds was tested by the FRET method, and most of them showed significant inhibition of Mpro. Preliminary analysis revealed that the presence of the glycosidic group was detrimental to the activity of the compounds, in addition the position of the hydroxyl substituent had an effect on the activity of the compounds. Reliable and predictive CoMFA (q2 = 0.541, r2 = 0.998, SEE = 0.039) and CoMISA (q2 = 0.554, r2 = 0.999, SEE = 0.034) models were developed, and the compounds were analyzed by 3D-QSAR with modeled steric, electrostatic, hydrogen bond donor, and hydrophobic fields. A series of compounds were synthesized and characterized, which showed similar experimental and predicted activities, with the activity of 15d (IC50 = 0.74 ± 0.04 uM) exceeding that of the template molecule 15 (0.98 ± 0.13 uM). Subsequently, molecular docking revealed the binding mode of 15d to Mpro and verified the predictions of steric, hydrogen bond donor, and hydrophobic field. In conclusion, these findings provide ideas for subsequent structural studies of flavonoids that could be used in the development of flavonoid-type SARS-CoV-2 Mpro inhibitors.

Efficient Production of 4’-Hydroxydihydrochalcones Using Non-Conventional Yeast Strains

The quest for novel therapeutic agents has rekindled interest in natural products, particularly those derived from biotransformation processes. Dihydrochalcones, a class of plant secondary metabolites, exhibit a range of pharmacological properties. Chalcone and dihydrochalcone compounds with the characteristic 4’-hydroxy substitution are present in ‘dragon’s blood’ resin, known for its traditional medicinal uses and complex composition, making the isolation of these compounds challenging. This study investigates the efficient production of 4′-hydroxydihydrochalcones using non-conventional yeast strains. We evaluated the biotransformation efficiency of various 4′-hydroxychalcone substrates utilizing yeast strains such as Yarrowia lipolytica KCh 71, Saccharomyces cerevisiae KCh 464, Rhodotorula rubra KCh 4 and KCh 82, and Rhodotorula glutinis KCh 242. Our findings revealed that Yarrowia lipolytica KCh 71, Rhodotorula rubra KCh 4 and KCh 82, and Rhodotorula glutinis KCh 242 exhibited the highest conversion efficiencies, exceeding 98% within one hour for most substrates. The position of methoxy substituents in the chalcone ring significantly influenced hydrogenation efficiency. Moreover, we observed isomerization of trans-4′-hydroxy-2-methoxychalcone to its cis isomer, catalyzed by light exposure. This study underscores the potential of using yeast strains for the sustainable and efficient production of dihydrochalcones, providing a foundation for developing new therapeutic agents and nutraceuticals.

New potent muscarinic receptor ligands bearing the 1,4-dioxane nucleus: Investigation on the nature of the substituent in position 2.

A new series of muscarinic acetylcholine receptor (mAChR) ligands obtained by inserting different substituents in position 2 of the potent 6,6-diphenyl-1,4-dioxane antagonists 4 and 5 was designed and synthesized to investigate the influence of steric bulk on the mAChR affinity. Specifically, the insertion of a 2-methyl group, affording compounds 6 and 9, resulted as the most favorable modification in terms of affinity for all muscarinic subtypes. As supported by computational studies performed on the hM1 receptor, this substituent may contribute to stabilize the ligand within the binding site by favoring the formation of stable interactions between the cationic head of the ligand and the residue D105. The increase of steric bulk, obtained by replacing the methyl group with an ethyl (7 and 10) and especially a phenyl substituent (8 and 11), caused a marked decrease of mAChR affinity, demonstrating the crucial role played by the steric bulk of the 2-substituent in the mAChR interaction. The most intriguing result was obtained with the tertiary amine 9, which, surprisingly, showed two different pKi values for all mAChRs, with preferential subpicomolar affinities for the M1, M3, and M4 subtypes. Interestingly, biphasic curves were also observed with both the eutomer (S)-(-)-9 and the distomer (R)-( + )-9.

The Role of the Nitro Group on the Formation of Intramolecular Hydrogen Bond in the Methyl Esters of 1-Vinyl-Nitro-Pyrazolecarboxylic Acids

All reactions involving the nitrogen atom in 3(5)-substituted pyrazoles inevitably lead to a mixture of N-substituted 3- and 5- isomers due to tautomerism. The position of substituent can affect the behavior of N-vinyl isomers, in particular, the ability of some functional groups to form =C-H...O or =C-H...N weak hydrogen bonding type interaction with α-hydrogen of vinyl group due to steric reasons. Moreover, the additional substituents in the pyrazole ring can further influence the possibility and nature of specific intramolecular interactions. Here we have shown the effect of the nitro group on the formation of hydrogen bonds in methyl esters of 1-vinyl-4-nitro-3(5)- and 1-vinyl-5-nitro-3(5)-pyrazole carboxylic acids. A comprehensive study, including synthesis, quantum chemical calculations, NMR and XRD analysis, allowed to conclude that, contrary to expected, in the methyl ester of 1-vinyl-4-nitro-5-pyrazolecarboxylic acid, the formation of a planar conformation is unfavorable, preventing formation of a classical hydrogen bond. On the other hand, there is a hydrogen bond between the nitro group and vinyl group in 1-vinyl-5-nitro-pyrazolecarboxylic acids.

Captodative Versus Push‐Pull Aromatic Cyclopentadienyl Derivatives

ABSTRACTThe problem of whether and how the captodative aromatic systems with the donor and acceptor substituents at the same carbon atom of the C=C bond can be more stable than the π‐conjugated push‐pull counterparts with the two substituents in the vicinal position is analyzed for cyclopentadienyl derivatives possessing an aromatic cyclopentadienyl ring. The analysis of electronic, magnetic, and structural criteria of aromaticity showed that among typical organic donors, such as amines NR3, ethers R2O, guanidine (NH2)2C=NH, siloxane O(SiH3)2, silatrane, the captodative isomers [cyclopentadienylium]−C(X+) = CH2 can be more stable than their push‐pull isomeric counterparts [cyclopentadienylium]−—CH=CH—X+. The largest energy difference in favor of the former was found to be ca. 13 kcal/mol for X = NH=C(NH2)2.

Nitrogen-rich sulfur-containing heterocyclic adsorbents for effective selective adsorption of Au(III)/Pd(II)/Pt(IV)

Recovering precious metals from secondary resources has elicited considerable attention, and exploring an efficient adsorbent is a challenge. In this work, we have specifically tailored three highly effective adsorbents (THDA@PEI, DCTA@PEI and DCTD@PEI) by crosslinking PEI with sulfur-containing heterocyclic cross-linking agents (2,5-thiophenedicarboxaldehyde, 2,4-dichlorothiazole and 3,4-dichloro-1,2,5-thiadiazole) for recovery of Au(III), Pd(II), and Pt(IV). These agents are distinguished by a range of nitrogen atom counts that extend from zero to two, offering a foundation for exploring the correlation between their molecular structure and adsorption performance. THDA@PEI, DCTA@PEI, and DCTD@PEI exhibit remarkable adsorption capacities for Au(III), Pd(II), and Pt(IV), with values reaching up to 2169, 2240, and 2536 mg/g for Au(III), 771, 886, and 846 mg/g for Pd(II), and 832, 1021, and 887 mg/g for Pt(IV), respectively. Among the three materials, DCTD@PEI stands out with a broader pH applicability range for both gold (pH 2 to 9) and platinum (pH 1 to 11) adsorption and exhibits a more rapid adsorption rate for Au and Pd. The adsorption processes of the three adsorbents on precious metals are spontaneous and entropy-increasing processes. Increasing the adsorption temperature could improve the adsorption performance of the three adsorbents, except for Pd adsorption by DCTD@PEI. All of the three adsorbents exhibit good selectivity and reusability for Au, Pd, and Pt, with DCTA@PEI being the most outstanding. It is observed that an increase in nitrogen content in the adsorbents correlates positively with the improvement of key performance indicators, including a wider pH range, higher adsorption capacity, faster kinetics, better selectivity, and enhanced reusability, while the substituent positions of crosslinking agents also have a strong impact on the adsorption performance, especially for Pd and Pt.

Investigating the Catalytic Site of Human 15-Lipoxygenase-1 via Marine Natural Products.

Human 15-lipoxygenase-1 (15-LOX-1) is a key enzyme that possesses an important role in (neuro)inflammatory diseases. The pocket of the enzyme plays the role of a chiral catalyst, and therefore chirality could be an important component for the design of effective enzyme inhibitors. To advance our knowledge on this concept, we developed a library of the identified chiral 15-LOX-1 inhibitors and applied cheminformatic tools. Our analysis highlighted specific structural elements, which we integrated them in small molecules, and employed them as "smart" tools to effectively navigate the chemical space of previously unexplored regions. To this purpose, we utilized the marine derived natural product phosphoeleganin (PE) among with a small library of synthetic fragment derivatives, including a certain degree of stereochemical diversity. Enzyme inhibition/kinetic and molecular modelling studies has been performed in order to characterize structurally novel PE-based inhibitors, which proved to present a different type of inhibition with low micromolar potency, according to their structural features. We demonstrate that different warheads work as anchor, and either guide specific stereochemistry, or causing a time-depended inhibition. Finally, we prove that the positioning of the chiral substituents or/and the favorable stereochemistry can be crucial, as it can lead from active to completely inactive compounds.

Structural and spectroscopic characterization of N1,N2-diphenylacenapthylene-1,2-diimines and the influence of substituents on the viscosity of alkyl magnesium solutions

Butyl octyl magnesium solutions are important raw materials in various chemical processes but suffer from their high reactivity with even traces of water, protic solvents or oxygen and an increased viscosity in hydrocarbon solution due to the formation of polymeric structures. N1,N2-diphenylacenaphthylene-1,2-diimines (BIANs) have already been identified as potential candidates to reduce the viscosity of alkyl magnesium solutions and this study provides a systematic insight into the dependence of this ability on the position and structures of substituents on the BIAN. Besides the various BIANs, ZnCl2 complexes and hydrogenated derivatives were characterized and tested for their ability to reduce the viscosity. HPLC-high resolution mass spectrometry, MALDI-ToF mass spectrometry, but most important FTIR and NMR experiments under inert conditions have been used to shine light on the interaction of the different BIAN derivatives with alkyl magnesium solutions. Hydrogenated BIANs, especially those with bulky alkyl groups in the ortho position(s) have been identified as the most promising candidates. An additional benefit of the hydrogenated species is that in contrast to BIANs and BIAN-Zn complexes they do not undergo permanent chemical modification and can be reused after extraction.

Synthesis, crystal structure and Hirshfeld surface analysis of a new copper(II) complex based on diethyl 2,2'-(4H-1,2,4-triazole-3,5-di-yl)di-acetate.

The title compound, bis-[μ-2,2'-(4H-1,2,4-triazole-3,5-di-yl)di-acetato]-bis-[di-aqua-copper(II)] dihydrate, [Cu2(C6H5N3O4)2(H2O)4]·2H2O, is a dinuclear octa-hedral CuII triazole-based complex. The central copper atoms are hexa-coordinated by two nitro-gen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxyl-ate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water mol-ecules. Two additional solvent water mol-ecules are linked to the title mol-ecule by O-H⋯N and O⋯H-O hydrogen bonds. The crystal structure is built up from the parallel packing of discrete supra-molecular chains running along the a-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯O/O⋯H (53.5%), H⋯H (28.1%), O⋯O (6.3%) and H⋯C/C⋯H (6.2%) inter-actions. The crystal studied was twinned by a twofold rotation around [100].

Mesoporous g-C3N4/ZnFe2O4/TCPP nanocomposite for selective liquid-phase oxidation of alcohols to aldehydes under visible light irradiation

This study provides a viable strategy for the production of aromatic benzaldehydes by a three-component magnetic recoverable photocatalyst. The novel photocatalyst was fabricated by modification of Graphitic carbon nitride (g-C3N4) using ZnFe2O4 magnetic nanoparticles and Tetrakis(4-carboxyphenyl)porphyrin (TCPP) and labeled as CFP where C is the carbonic substrate, F shows the magnetic component and P demonstrated TCPP porphyrin. The optimized CFP photocatalyst demonstrated approximately 96 % conversion and 99 % selectivity for the oxidation of benzyl alcohol to benzaldehyde. The photocatalytic reaction carried out in the presence of acetonitrile and H2O2 as solvent and oxidant under LED lamp (15 W) irradiation. The results reveal that the values of conversion and selectivity of various types of benzylic alcohols are attributed to the aromaticity and position of substituents on the benzene ring. The reusability of CFP photocatalyst was investigated up to the fourth cycle, and it revealed any significant loss of photocatalytic oxidation activity, which is related to high structural stability of photocatalyst.

Effect of hydrophilic group substituent position on adhesion at the emulsified asphalt/aggregate interface

Emulsified asphalt offers energy-saving and environmental benefits, aligning with low-carbon, high-quality development requirements. However, poor adhesion hampers the development of emulsified asphalt. The hydrophilic group substituent position significantly influences the adhesive strength at the emulsified asphalt/aggregate interface. To further elucidate this mechanism, this study employs molecular dynamics (MD) simulation techniques, focusing on the positional variations of the hydrophilic group in the sodium dodecylbenzene sulfonate molecule, particularly the SDBS2–1#, SDBS3–1#, and SDBS4–1# configurations. The objective is to enhance adhesion between these two materials. The simulation results were validated through macroscopic demulsification experiments, encompassing a comprehensive analysis of various parameters, including relative concentration distribution, diffusion coefficient, adhesion work, electron density difference, and electrostatic potential distribution. The result demonstrated a strong synergistic effect between the emulsifiers' molecular structure and the aggregates' chemical composition. The emulsifier SDBS4–1# with para-substitution enhances adhesion at the interface between the emulsified asphalt and alkaline aggregate (CaCO₃) by 50.4 %. The emulsifier SDBS2–1# with ortho-substitution enhances adhesion at the interface between the emulsified asphalt and acidic aggregate (SiO₂) by 33.3 %. Furthermore， the emulsifiers SDBS4–1# and SDBS2–1# promote the accumulation of electrons in asphalt molecules on CaCO₃ and SiO₂ surfaces, respectively. This increase in electron accumulation enhances the adhesion performance between emulsified asphalt and aggregate at their interface. Therefore, optimizing the structure of emulsifier molecules significantly increases the bonding strength between emulsified asphalt and aggregate surfaces.

Effect of substituent position on assembly of compounds bearing ortho/para over meta directing groups

This research investigated the impact of substituent location on intermolecular interactions and crystal packing. A class of N-(dichlorophenyl)-2-pyrazincarboxamide derivatives were synthesized and characterized: 2,5-dichloro (2,5-diCl), 3,4-dichloro (3,4-diCl), and 2,4-dichloro (2,4-diCl). Comparison with their monochloro counterparts (2-chloro (2-Cl), 3-chloro (3-Cl), and 4-chloro (4-Cl)) revealed a distinct structural variation upon introducing a second chlorine substituent at the ortho/para positions of the phenyl ring. Conversely, incorporating a second chlorine atom at the meta position resulted in similar molecular packing. These findings suggest that ortho/para directing groups play a dominant role in dictating the crystal assemblies of the studied compounds.

Substituent effects in 2-hydroxybenzophenone-based ultraviolet absorbers

2-Hydroxybenzophenone is the simplest molecule among benzophenone-based UV absorbers. Changing the position and type of substituents affects the strength of intramolecular hydrogen bonding and thus modulates the UV absorption properties. In this work, 132 2-hydroxybenzophenone-based UV absorbers with different substituent positions and species were designed to investigate the substituent effect in their UV absorption properties. The results show that when the substituent positions are the same, the characteristic peaks of the compounds containing substituents of the same group of atoms or homologous groups correspond to similar wavelengths. When the substituent groups are the same, the wavelength redshift of the characteristic peaks of the UV absorption spectra of the compounds of the NX and NZ classes is more pronounced than that of the remaining species, and the substituent group containing N atoms causes the molecule to have a more pronounced wavelength redshift. The redshift of the characteristic absorption peaks corresponding to the wavelengths decreases with the increase of the energy level difference. Atoms-in-molecules (AIM) analysis showed that the electron-absorbing group in the compound enhances the hydrogen bond strength to a lesser extent than the electron-donating group. Natural Bond Orbital (NBO) analysis further revealed that the type and position of the substituent groups in the molecular structure influenced the strength of the intramolecular hydrogen bonding by affecting the distribution of the charges among individual atoms in the 2-hydroxybenzophenone molecules. This work aims to reveal the effect of substituents on the UV absorption properties of 2-hydroxybenzophenone-based molecules and to provide theoretical guidance for the design of such UV absorber molecules absorbing UV light at specific wavelengths.

Modeling hydration of graphene oxide (GO) – Does size matter?

The biomedical applications of graphene-based materials become one of hot scientific and technological topics in the last few years. Flake graphene oxide (GO) is considered as one of the promising materials for biomedical use due to a number of specific properties, in particular in design of advanced drug delivery systems (DDS). The key factor in the formation of non-covalently bonded complexes for drug transport is the strength of non-covalent interactions of the carrier with both the drug and the environment. In the current work, we have focused on molecular modeling of solvation of zigzag-edged graphene oxide, functionalized with hydroxyl and carboxyl substituents. The hydration was determined from the magnitude of weak intermolecular interactions of GO with one or two water molecules. Our goal was to establish the dependence of the degree and type of functionalization, as well as the size of graphene flakes and the position of hydrophilic substituents on the number and strength of H-bonds. All calculations were performed using density functional theory (DFT) at the B3LYPD3BJ/6-311++G** level. The effect of water solvent was established using an explicit (discrete) model of solvent.

Catalyst-Free Dynamic Covalent C=C/C=N Metathesis Reaction for Associative Covalent Adaptable Networks.

Covalent adaptable networks (CANs), leveraging the dynamic exchange of covalent bonds, emerge as a promising material to address the challenge of irreversible cross-linking in thermosetting polymers. In this work, we explore the introduction of a catalyst-free and associative C=C/C=N metathesis reaction into thermosetting polyurethanes, creating CANs with superior stability, solvent resistance, and thermal/mechanical properties. By incorporating this dynamic exchange reaction, stress-relaxation is significantly accelerated compared to imine-bond-only networks, with the rate adjustable by modifying substituents in the ortho position of the dynamic double bonds. The obtained plasticity enables recycle without altering the chemical structure or mechanical properties, and is also found to be vital for achieving shape memory functions with complex spatial structures. This metathesis reaction as a new dynamic crosslinker of polymer networks has the potential to accelerate the ongoing exploration of malleable and functional thermoset polymers.