Publications by authors named "Jianquan Weng"

Phthalocyanines have been widely investigated as electrochromic materials because of their large conjugated structure. However, they have shown limited applicability due to their complex electrochromism mechanism and low solubility in common organic solvents. Replacement of central metal ions in phthalocyanines affects their stability and is responsible for various electrochromic phenomena, such as color change.

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Article Synopsis
  • New insecticides with unique mechanisms are needed to combat rising pesticide resistance.
  • Researchers designed and tested novel aryl isoxazoline derivatives, confirming their structures and finding excellent insecticidal activity against certain pests.
  • One specific compound showed promising results comparable to an existing insecticide, with potential for further development based on structure-activity relationships and molecular analysis.
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Article Synopsis
  • * The research focused on synthesizing these compounds and confirmed their structures using advanced techniques such as H NMR and HRMS.
  • * One specific compound showed significant fungicidal activity with 92.3% inhibition against a plant pathogen and had no harmful effects on crops, indicating its potential as a safe fungicide.
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A series of new thiazole-based stilbene analogs were designed, synthesized and evaluated for DNA topoisomerase IB (Top1) inhibitory activity. Top1-mediated relaxation assays showed that the synthesized compounds possessed variable Top1 inhibitory activity. Among them, ()-2-(3-methylstyryl)-4-(4-fluorophenyl)thiazole () acted as a potent Top1 inhibitor with high Top1 inhibition of ++++ which is comparable to that of CPT.

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To discover an efficient and convenient method to synthesize C2-arylacylated benzothiazoles as potential drug scaffolds, a novel [bis(trifluoroacetoxy)iodo]benzene(PIFA)/KOH synergistically promoted direct ring-opening C2-arylacylation reaction of -benzothiazoles with aryl methyl ketones has been developed. Various substrates were tolerated under optimized conditions affording the C2-arylacylation products in 70-95% yields for 38 examples. A plausible mechanism was also proposed based on a series of controlled experiments.

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An experiment was performed to study the inactivation effect of aerobic composting on heavy metals in maggot, pig and chicken manures. After composting, Cu mainly occurred in the oxidizable (OXI) fraction with a percentage distribution above 54%. Zn and Cd mainly existed in the bioavailable factor (BF), which has strong activity, with percentage distributions greater than 88.

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Natural products are a source of many novel compounds with biological activity for the discovery of new pesticides and pharmaceuticals. Quinoxaline is a fused -heterocycle in many natural products and synthetic compounds, and seven novel quinoxaline derivatives were designed and synthesized three steps. Pesticidal activities of title quinoxaline derivatives were bioassayed.

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The KSO-mediated hydroxyalkylation of 2-benzothiazoles with aliphatic alcohols in aqueous solution was described. The mild and convenient protocol generated a series of hydroxyalkylated benzothiazoles in moderate to good yields. Besides, benzimidazole and ethers were also compatible in this reaction, leading to corresponding C2 ether-substituted heteroarenes.

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Background: In recent years, carboxamide fungicides, targeting succinate dehydrogenase (SDH), have shown highly efficient and broad spectrum fungicidal activity. Structure-activity relationship (SAR) results for these commercial fungicides show that the carboxamide group was a key active group. This is useful information for the discovery of new pyrazole carboxamide derivatives with fungicidal activity.

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Background: Quinoline derivatives possess excellent fungicidal activity against rice blast, but quinoline derivatives have not been thoroughly explored as fungicides. In the process of designing new fungicides, the 1,1,1,2,3,3,3-heptafluoropropan-2-yl group was introduced in order to find new structure quinoline derivatives.

Results: Seventeen new quinoline derivatives containing 1,1,1,2,3,3,3-heptafluoropropan-2-yl moiety were designed and synthesised.

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In our continuing effort to discover natural product-based pest management agents, derivatives of 3,5-dimethoxystilbene were synthesized yielding 27 new and six known compounds. Compounds 11 and 12 showed strong Aedes aegypti larvicidal activity (LC 45.31 and 49.

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Background: Aedes aegypti is a major mosquito vector for the transmission of serious diseases, especially dengue and yellow fever. More than 1 billion people in developing countries are at risk. The widespread and continual use of pesticides can lead to resistant mosquitoes.

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Highly enantioselective Friedel-Crafts C2-alkylation reactions of 3-substituted indoles with α,β-unsaturated esters and nitroalkenes were developed using chiral Lewis acids as catalysts, which afforded chiral indole derivatives bearing C2-benzylic stereogenic centers in good to excellent yields (up to 99%) and enantioselectivities (up to 96% ee).

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A series of novel 1,2,4-triazolo[4,3-a]pyridin-3(2H)-one derivatives were synthesized and identified by (1)H NMR, single crystal X-ray diffraction, elemental analysis or HRMS, and their herbicidal activities were determined at different concentrations. It was found that some of the title compounds possess high herbicidal activity. Furthermore, DFT calculation was used to study the SAR.

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Background: 1,2,4-Triazolo[4,3-a]pyridine derivatives represent a new series of compounds that possess good herbicidal activity against Echinochloa crusgalli (L.) Beauv., Setaria faberii, Digitaria sanguinalis (L.

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A series of novel 1,2,4-triazolo[4,3-a]pyridines were synthesized, and their structures were characterized by (1) H NMR, MS, elemental analysis, and single-crystal X-ray diffraction analysis. The antifungal activities were evaluated. The antifungal activity results indicated that the compound 2b, 2g, 2p, and 2i exhibited good activities.

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A highly enantioselective Friedel-Crafts alkylation reaction of indoles with acyclic α-substituted β-nitroacrylates is developed under the catalysis of Ni(ClO4)2-bisoxazoline complex at 1 mol % catalyst loading, affording chiral indolic β-nitroesters bearing all-carbon quaternary stereocenters in excellent yields and ees of up to 97%. Transformation of one of the products to β(2,2)-amino ester and tetrahydro-β-carboline through nitro reduction and sequential Pictet-Spengler cyclization was exemplified.

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A series of new N,N'-diacylhydrazine derivatives were designed and synthesized. Their structures were verified by 1H-NMR, mass spectra (MS) and elemental analysis. The antifungal activities of these N,N'-diacylhydrazines were evaluated.

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In order to investigate the biological activity of 1,2,4-triazole compounds, seventeen novel 1,2,4-triazole derivatives containing 1,2,3-thiadiazole moieties were synthesized by multi-step reactions under microwave assisted conditions. The structures were characterized by 1H-NMR, 13C-NMR, MS and elemental analyses. The target compounds were evaluated for their in vivo fungicidal activities against Corynespora cassiicola, Pseudomonas syringae pv.

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In the title compound, C(11)H(10)BrNO(2), the dihedral angle between the benzene and cyclo-propane ring planes is 49.4 (3)°. The C-C-N-O torsion angle is -175.

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A series of new 3-[(5-aryl-1,3,4-oxadiazol-2-yl)methy])benzo[d]thiazol-2(3H)-ones were synthesized by reaction of (5-substituted-2-oxobenzothiazolin-3-yl)-acetohydrazide with various aromatic acids in POCl(3) under reflux conditions. The structures of the title compounds were confirmed by ¹H-NMR, ¹³C-NMR, IR, MS and elemental analysis. Furthermore, the structure of compound 4i was determined by single-crystal X-ray diffraction.

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To develop novel inhibitors of ketol-acid reductoisomerase, a series of (oxdi/tri)azoles derivatives was synthesized and characterized by (1)H  NMR, MS, elemental analyses, and crystallography. According to the biological activities of these compounds obtained both in vivo and in vitro, compound 4-cyclopropyl-3-((4-fluorobenzyl)thio)-5-methyl-4H-1,2,4-triazole showed excellent KARI inhibitory activity (100% at 100 μg mL (-1)  in vitro). In addition, most of the title compounds exhibited good herbicidal activity against Brassica campestris in vivo.

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1,4-Bis(4-tert-but-ylbenz-yl)piperazine.

Acta Crystallogr Sect E Struct Rep Online

November 2011

The complete mol-ecule of the title compound, C(26)H(38)N(2), is generated by a crystallographic inversion centre. The piperazine ring adopts a chair conformation with pseudo-equatorial substituents. In the crystal, mol-ecules inter-act only by van der Waals forces.

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In the title compound, C(11)H(7)Cl(3)N(3)O, the dihedral angle between the benzene and cyclo-propane rings is 85.8 (2)°. In the crystal, mol-ecules are linked by C-H⋯O inter-actions, generating C(5) chains propagating in the a-axis direction.

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2,3-Dichloro-pyridine.

Acta Crystallogr Sect E Struct Rep Online

September 2011

The complete mol-ecule of the title compound, C(5)H(3)Cl(2)N, is generated by crystallographic twofold symmetry, which forces the pyridine N atom and the opposite C-H group to be statistically disordered. In the crystal, weak aromatic π-π stacking [centroid-centroid separation = 3.805 (4) Å and slippage = 1.

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