Triethyl Orthoformate Research Articles

General Access to Acenaphthene-FusedN-Heterocyclic Carbene Ligands

We communicate a general method for the syntheses of acenaphthene-fused imidazolinium salts that are direct precursors to augmented N-heterocyclic carbenes with a fixed cis geometry. Reduction of bis(imino)acenaphthene ligands with a LiAlH4/AlCl3 reagent mix initially produced the corresponding 1,2-diamines which, upon ring-closing reaction with triethyl orthoformate in acidic solution, gave the requisite ionic intermediates. Formation of the carbenes was then shown by preparation of selected [Cu(NHC)] complexes that were obtained via treatment of the respective imidazolinium salt with base in the presence of a Cu(I) source.

Phenol-Tethered N-Heterocyclic Benzimidazol-2-ylidene Carbene Interactions with the Early Lanthanides

The cyclization of salophan with triethyl orthoformate in the presence of HBr results in a bisphenol benzimidazolium carbene precursor 1,3-bis(2-hydroxybenzyl)-2H-benzimidazolium bromide (H3OBBIm). By reacting H3OBBIm in a one-pot synthesis with Ln(N(SiMe3)2)3 (Ln = La–Sm excl. Pm) and an excess of KN(SiMe3)2, the N-heterocyclic carbene (NHC) complexes, [Ln(OBBIm)2(N″)][K2THFx], can be prepared and isolated. These complexes were characterized by single-crystal X-ray diffraction, solution- and solid-state UV–vis–near-infrared spectroscopy, and 1H NMR. These complexes possess distorted pentagonal bipyramid geometries.

Alternative pathways of the reaction between acetophenone and triethyl orthoformate

Alternative pathways of the reaction between acetophenone and triethyl orthoformate

Synthesis, Characterization and Evaluation of Some Meldrum's Acid Derivatives as Lubricant Additives

Aminomethylene Meldrum’s acid derivatives were synthesized by a three-component, one-pot reaction of Meldrum's acid with triethyl orthoformate and different aromatic amines. The prepared compounds were characterized using Fourier transform infrared (FT-IR), nuclear magnetic resonance (1H NMR and 13C NMR) and evaluated as anti-corrosion and anti-rust additives by blending with base lubricating oil, according to the American Society of Testing and Materials (ASTM-D130 and ASTM-D665). The blends of the synthesized compounds with the base lubricating oil showed better anti-rust and anti-corrosion effects than the base oil Blank).

Synthesis, characterization and biological evaluation of the novel chromenopyridothiazolopyrimidines and chromenopyridopyrimidothiazolo-pyrimidines

Friedländer reaction of 4-aminocoumarin-3-carboxaldehyde (1) with thiobarbituric acid provided 2-thioxochromenopyridopyrimidine 2 which employed as a synthetic intermediate to create a novel annulated chromenopyridothiazolopyrimidines. Treatment of compound 2 with a diversity of nucleophiles including; dibromoethane, oxalyl chloride, phenacyl bromide, chloroacetic acid, 3-chloropentanedione, ethyl 2-chloro-3-oxobutanoate, chloroacetonitrile and bromomalononitrile afforded chromenopyridothiazolopyrimidines 3–10, respectively. Acidic hydrolysis of carbonitrile 10 afforded the corresponding carboxamide derivative 11. Compound 11 reacted with some mono-electrophilic reagents namely acetyl chloride, benzoyl chloride, chloroacetyl chloride, triethyl orthoformate, diethyl carbonate, and carbon disulfide producing the first known chromeno[3′,4′:5,6]pyrido[2,3-d]pyrimido [4',5':4,5][1,3]thiazolo[3,2-a]pyrimidines 12–17. The antimicrobial and anticancer activities were estimated for the synthesized products and some of them appeared notable activities. The structural elucidation of the newly synthesized products was determined using analytical and spectroscopic data.

One-Pot Synthesis, E-/Z-Equilibrium in Solution of 3-Hetarylaminomethylidenefuran-2(3H)-ones and the Way to Selective Synthesis of the E-Enamines.

We describe a method to synthesize a new class of hetarylaminomethylidene derivatives of furan-2(3H)-ones. The method uses 5-(4-chlorophenyl)furan-2(3H)-one, triethyl orthoformate, and heterocyclic amines with different ring sizes and heteroatoms under refluxing in absolute isopropyl alcohol. The obtained enamines exist in an equilibrium of E- and Z-isomers, whose configurations relative to the double exocyclic C=C bond were confirmed with a set of NMR spectroscopy data. The E-/Z-equilibrium of the synthesized compounds is affected by the configuration of the intermediate, the volume of its substituents, the site of enolate attack, the presence of intramolecular interactions of amino components, the time of the transformation, the order of mixing of the initial reagents, and the use of polar solvents in the NMR experiment. The advantages of the method are that the reaction time is short, the product yield is high, and product purification is easy.

The Adjustability of Physicochemical Properties: Comparison of 1-Vinyl-5H-tetrazole and 1-Allyl-5H-tetrazole as Ligands in 3d Metal Energetic Coordination Compounds

Energetic coordination compounds (ECCs) show promising properties to be used as potential substitutes for highly toxic lead-containing primary explosives. The concept is to combine the three building blocks: (i) ligand, (ii) transition metal, and (iii) anion, acting as (i) fuel, (ii) matrix, and (iii) oxidizer (e.g., ClO4-, NO3-, ClO3-) or energetic component (e.g., DN-, N3-, picrate, styphnate, trinitrophloroglucinate). By variation of the ligands, the complexes' properties can be adjusted toward their desired performance and sensitivities. In the present study, 1-vinyl-5H-tetrazole (1-VTZ, 1) and 1-allyl-5H-tetrazole (1-ATZ, 2) were used as nitrogen-rich endothermic ligands to form 3d metal (Mn2+, Fe2+, Cu2+, Zn2+, Co2+, Ni2+)-based ECCs. The influence of the introduction of an unsaturated C-C bond (1-ETZ vs 1-VTZ and 1-PTZ vs 1-ATZ) on the performance and sensitivity of the complexes is discussed, as is the lengthening of the alkenyl chain (1-VTZ vs 1-ATZ). For further insights, the novel complexes were compared to literature-known complexes based on N1-substituted C2- and C3-derived tetrazole ligands, respectively. The ligand 1-VTZ (1) was prepared by elimination of hydrogen chloride from 1-(2-chloroethyl)-5H-tetrazole in methanolic KOH solution. 1-ATZ (2) was obtained by a heterocyclization reaction of allylamine with triethyl orthoformate and sodium azide in an acetic acid medium. All compounds were intensively characterized with analytical methods such as XRD, IR, EA, DTA, TGA, and sensitivity measurements (IS and FS). The energetic performances were visibly evaluated in fast heating experiments. Furthermore, PETN initiation and laser ignition experiments were carried out for promising ECCs.

A coumarin-based fluorescent chemosensor as a Sn indicator and a fluorescent cellular imaging agent.

In the present study, fluorogenic coumarin-based probes (1-3) through condensation of 4-hydroxy coumarin with malondialdehyde bis(diethyl acetal)/triethyl orthoformate were prepared. The absorption and fluorescence emission properties of 2b and 3 in different solvents were studied, and a considerable solvatochromic effect was observed. The sensitivity of chemosensors 2b and 3 toward various cations and anions was investigated. It was revealed that compound 3 had a distinct selectivity toward Sn2+, possibly via a chelation enhanced quenching mechanism. The fluorescence signal was quenched over the concentration range of 6.6-120 μM, with an LOD value of 3.89 μM. The cytotoxicity evaluation of 3 against breast cancer cell lines demonstrated that the chemosensor was nontoxic and could be used successfully in cellular imaging. The probe responded to tin ions not only via fluorescence quenching, but also through colorimetric signal change. The change in optical properties was observed in ambient conditions and inside living cells.

Design, synthesis, antimicrobial, antibiofilm evaluation and Z/E-isomerization of novel 6-((arylamino)methylene)benzo[a] phenazin-5(6H)-ones induced by organic solvent.

New 6-((arylamino)methylene)benzo[a]phenazin-5(6H)-one derivatives were synthesized, and good-to-high yields were achieved through one-pot, four-component condensation of 2-hydroxy-1,4-naphthoquinone, 1,2-phenylenediamine, aromatic amines and triethyl orthoformate using formic acid as catalyst under solvent-free conditions at 90 °C. The structure of these new compounds was confirmed using FT-IR and 1H-NMR as well as MS spectroscopy. Investigation of spectroscopy data indicated that the synthesized compounds exist in the keto-enamine tautomeric form and undergo Z/E-isomerization around the C[double bond, length as m-dash]C bond in DMSO-d6 at room temperature. Furthermore, intramolecular hydrogen bond has been observed in the synthesized E- and Z-ketoenamines. The noticeable features of the present procedure availability of starting materials, very simple operation, easy work-up, short reaction times, good to high yields and no need for column chromatography separation of benzophenazine enamines. The newly synthesized compounds were evaluated in vitro for their antibacterial, antifungal and antibiofilm activities against some of the tested microorganisms. The results demonstrated that compound 6b showed the maximum antibacterial activity, 6d exhibited the maximum antifungal activity and 6b had the most efficiency to inhibit biofilm formation of Bacillus subtilis (80%) at 200 μg mL-1 concentration.

New benzimidazole derivatives: Design, synthesis, docking, and biological evaluation

The aim of this study was to synthesize novel enaminonitrile derivatives starting from 2-aminobenzimidazole and utilize this derivative for the preparation of novel heterocyclic compounds and assess their function for biological activity screening. The key precursor N-(1H-benzo[d]imidazol-2-yl)carbonohydrazonoyl dicyanide (2) was prepared in pyridine by coupling of diazotized 2-aminobenzimidazole (1) with malononitrile. Compound 2 was subjected to react with various secondary amines such as piperidine, morpholine, piperazine, diphenylamine, N-methylglucamine, and diethanolamine in boiling ethanol to give the acrylonitriles (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(piperidin-1-yl)acrylonitrile (3), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-morpholinoacrylonitrile (4), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(piperazin-1-yl)acrylonitrile (5), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(diphenylamino)acrylonitrile (6), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)acrylonitrile (7), and (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(bis(2-hydroxyethyl)amino)acrylonitrile (8), respectively. It has been found that the behaviour of nitrile derivative 2 towards hydrazine hydrate to the creation of 4-((1H-benzo[d]imidazol-2-yl)diazenyl)-1H-pyrazole-3,5-diamine (9). The reaction of malononitrile with compound 2 in an ethanolic solution catalyzed with sodium ethoxide afforded 4-amino-1-(1H-benzo[d]imidazol-2-yl)-6-imino-1,6-dihydropyridazine-3,5-dicarbonitrile (11). Moreover, malononitrile reacted with 7 in a boiling ethanolic sodium ethoxide solution to give 2-(5-((1H-benzo[d]imidazol-2-yl)diazenyl)-4-amino-6-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)pyrimidin-2-yl)acetonitrile (14). Heating 7 in boiling acetic anhydride and pyridine afforded (2R,3R,4R,5S)-6-(((1E)-2-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-1-(N-acetylacetamido)-2-cyanovinyl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (15). When compound 15 is heated for a long time in refluxing DMF including a catalytic of TEA, cyclization occurs to give the corresponding (2R,3R,4R,5S)-6-((1-acetyl-3-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-4-amino-6-oxo-1,6-dihydropyridin-2-yl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (16). In addition, triethyl orthoformate was reacted with compound 7 in the presence of acetic anhydride to afford the corresponding ethoxymethyleneamino derivative (2R,3R,4R,5S)-6-(((1E)-2-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-2-cyano-1-(((E) ethoxymethylene)amino)vinyl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (17). Also, it has been found that heating a mixture of 7 with DMF/DMA in anhydrous xylene yielded compound (1E)-N'-((1E)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-2-cyano-1-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)vinyl)-N,N-dimethylformimidamide (18). In addition, compound 7, when reacted with several acid anhydrides, allowed the matching phthalimide derivatives 19–26. The results showed that compound 14 has significantly higher ABTS and antitumor activities than the other compounds. Molecular modelling was also studied for compounds 22 and 24. The viability of four many cell lines—the African green monkey kidney epithelial cells (VERO), human breast adenocarcinoma cell line (MCF-7), human lung fibroblast cell line (WI-38), and human hepatocellular liver carcinoma cell line (HepG2) was examined to determine the antitumor activities of the newly synthesized compounds. Also, it was found that compounds 9, 11, 15, 16, 22, 23, 24 and 25 are strong against HepG2 cell lines, while 16, 22, and 25 are strong against WI-38 cell lines. Moreover, it was also found that compounds 16 and 22 are strong against VERO cell lines. On the other hand, compounds 7, 14, 15, 16, and 22 are strong while the rest of the other compounds are moderate against the MCF-7 cell line. The result of docking showed that compound 24 got stabilized inside the pocket with a very promising binding score of − 8.12 through hydrogen bonds with Arg184 and Lys179, respectively.

Synthesis, Characterization and Antioxidant Evaluation of Some Tetrazole Derivatives

The present study introduces the synthesis of two series of tetrazole derivatives. Firstly, monosubstituted S1 was prepared by the reaction of ethyl 4-aminobenzoate with an amount of sodium azide and triethyl orthoformate in hot glacial acetic acid. Then, ethyl 4-(1H-tetrazol-1-yl) benzoate S1 was treated with a solution of hydrazine hydrate to prepare acetohydrazide S2. After that, tetrazole derivatives S3-S4 were prepared via the reaction of acetohydrazide S2 with various aromatic aldehydes. Secondly, compound 1,5-disubstituted tetrazole S5 was prepared from the reaction of aryl isothiocyanate with sodium azide in water presence. Then alkylation to compound S5 was made with ethyl chloroacetate to produce S6. In the next step, S6 was reacted with hydrazine hydrate to get acetohydrazide S7. Moreover, the produced S7 was reacted with some aromatic aldehydes for the synthesis of S8-S10. The structures of synthesized compounds were confirmed by the different available spectral methods, i.e., FTIR, 1H-NMR and 13C-NMR spectroscopy. The antioxidant activity of the synthesized compounds was evaluated by the use of 2,2-diphenyl-1-picrylhydrazyl. The results showed that compound S10 has the highest value as radical scavenging among the synthesized compounds.

Synthesis, photophysical properties, and biological activities of some new thienylpyridines, thienylthieno[2.3‐b]pyridines and related fused heterocyclic compounds

AbstractBoth 2‐(N‐arylcarbamoyl)methylsulfanyl‐3‐cyano‐5‐ethoxycarbonyl‐6‐methyl‐4‐(2′‐thienyl)pyridines 2a‐e and their isomers, 3‐amino‐2‐(N‐arylcarbamoyl)‐5‐ethoxy‐carbonyl‐6‐methyl‐4‐(2′‐thienyl)thieno[2,3‐b]pyridines 3a‐e were synthesized by reaction of ethyl 3‐cyano‐1,2‐dihydro‐6‐methyl‐4‐(2′‐thienyl)‐2‐thioxopyridine‐5‐carboxylate (1) with the respective N‐aryl‐2‐chloroacetamides in the presence of different basic catalysts. Compounds 3a‐e were used as precursors for synthesizing of pyridothienopyrimidinones 4a‐e, pyridothienotriazinones 5a‐e and tetrahydropyridothienopyrimidinones 6a‐c via treatment with triethyl orthoformate, nitrous acid, and/or 4‐chlorobenzaldehyde respectively. The photophysical properties of aminothienylthienopyridines 3a‐e and tetrahydropyridothieno‐pyrimidine‐4(3H)‐ones 6a‐c were studied and the fluorescence data revealed that all selected compounds possess AIE behaviors in solution and in solid state. Most of the prepared compounds were evaluated in vitro for their antibacterial and antifungal activities, and considerable results were obtained. Moreover, the cytotoxic activity of thienopyridines 3a‐d against MCF‐7 and HepG2 cell lines was evaluated and they showed moderate to very strong activity.

Benzochromenopyrimidines: Synthesis, Antiproliferative Activity against Colorectal Cancer and Physicochemical Properties.

Ten new differently substituted 3-benzyl-5-aryl-3,5-dihydro-4H-benzo[6,7]chromeno[2,3-d]pyrimidin-4,6,11-triones 3 were synthesized by a simple and cost-efficient procedure in a one-pot, three-component reaction from readily available ethyl 2-amino-4-aryl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carboxylates, benzylamine and triethyl orthoformate under solvent- and catalyst-free conditions. All the new compounds were screened for their antiproliferative activity against two colorectal-cancer-cell lines. The results showed that the compounds 3-benzyl-5-phenyl-3,5-dihydro-4H-benzo[6,7]chromeno[2,3-d]pyrimidine-4,6,11-trione (3a) and 3-benzyl-5-(3-hydroxyphenyl)-3,5-dihydro-4H-benzo[6,7]chromeno[2,3-d]pyrimidine-4,6,11-trione (3g) exhibited the most potent balanced inhibitory activity against human LoVo and HCT-116 cancer cells.

Imidazolylpyrrolone-Based Small Molecules as Anticancer Agents for Renal Cell Carcinoma.

An in silico study focused on known cancer-related target proteins, identified a selection of imidazo[4,5-b]pyrrolo[3,4-d]pyridines as potentially active. These compounds were prepared by a novel synthetic approach, designed and developed in-house, based on the reaction of 5-amino-4-cyanoformimidoyl imidazoles with N-substituted cyanoacetamides. The substituted imidazolylpyrrolones obtained, were cyclized intramolecularly to generate the intended imidazo[4,5-b]pyrrolo[3,4-d]pyridines in a process catalyzed by DBU. Treating the imidazolylpyrrolones with an excess of triethyl orthoformate and heating at 80 °C in the presence of acid catalysis led to imidazopyrrolodiazepines. These compounds were screened for their anticancer potential, using the renal cell carcinoma cell line model (A498 and 786-O cell lines). Two compounds exhibited IC50 values in the low micromolar range with a good selectivity index, when compared to non-neoplastic kidney cell line HK2 and the reference compounds rapamycin, cediranib and sunitinib.

2,6‐Di(1H‐tetrazol‐1‐yl)pyridine and its cupric chloride complex

Abstract2,6‐Di(1H‐tetrazol‐1‐yl)pyridine (DTP) was prepared by a four‐stage procedure, including step‐by‐step heterocyclization of both amino groups of 2,6‐diaminopyridine with triethyl orthoformate and sodium azide. According to quantum‐chemical calculations and single crystal X‐ray diffraction data, DTP crystallizes in the form of the thermodynamically most stable conformer and has an almost flat molecular geometry. DTP was found to react with CuCl2 ⋅ 2H2O in ethanol to give the [Cu(DTP)Cl2(H2O)]n complex, which is a 1D coordination polymer, formed at the expense of bridging DTP ligand via the tetrazole ring nitrogen atoms N4. Possible coordination cites in DTP molecule are discussed using the data of quantum chemical calculations. The pyridine ring nitrogen atom of DTP does not participate in the formation of either coordination or intermolecular hydrogen bonds. This is explained by the results of quantum chemical calculations showing that this atom is less basic than N3 and N4 atoms of DTP molecule.

Ionic liquid-based periodic mesoporous organosilicas: Metal/solvent-free synthesis of formamides and formamidines

We prepared a novel ionic liquid-based Periodic Mesoporous Organosilicas (PMOs) using a post-synthetic method. First, PMO containing amine unit (PMO-NH) was prepared as a result of the co-condensation of amine bis-silane precursor [bis[3-(triethoxysilyl)propyl]amine] and tetraethylorthosilicate (TEOS) in the presence of pluronic-123 under acidic conditions. In a second step, the amine units (NH) were reacted with perchloric acid and yielded ionic-PMO material (PMO-NH2+ClO4−). The materials possessed a hexagonal lattice with the highly ordered mesostructured being retained after the functionalization as evidenced by X-ray diffraction (XRD) analysis. The N2 adsorption-desorption measurement revealed that the final material (PMO-NH2+ClO4−) had a high BET surface area (350 m2/g) and pore size (4.8 nm). The obtained material was subsequently evaluated as a heterogeneous catalyst in the coupling reaction of amine/formic acid towards formamides and also in the preparation of formamidine derivatives. The reactions between various aryl amines and formic acid or triethyl orthoformate could proceed smoothly in the presence of PMO-NH2+ClO4−, giving a high yield of 85–99% with great selectivity (> 99%). This outstanding catalytic performance can be attributed to the presence of acidic ionic sites together with a high surface area of the obtained material.

Synthesis of environmentally benign new ionic liquids for the preparation of 2-aryl/heteroaryl benzimidazoles/benzoxazoles under ultrasonication

Ionic liquids (ILs) possess a broad spectrum and cutting-edge impact on promising and sustainable research works due to their utilization in academic as well as industrial applications. These are regarded as notable catalysts/solvents due to their distinct physical, thermal and chemical properties. Among the different ILs existing, imidazolinium salts are quite interesting because of their convenient preparation and widespread applications in organic catalysis. By keeping in mind aforesaid, we have synthesized a series of ionic liquids; symmetrical/unsymmetrical 1,3-dialkyl imidazolium/benzimidazolium salts from imidazole/benzimidazole with alkyl chlorides/bromides. Further, ILs with other counter-anions such as tetrafluoroborate (BF4−) and hexafluorophosphate (PF6−) in benzimidazolium group were developed by the reaction of N, N′-disubstituted o-phenylenediamine, triethyl orthoformate and ammonium chloride/tetrafluoroborate/ammonium hexafluorophosphate. By these ionic liquids, a series of substituted 1-alkyl-2-aryl-1H-benzo[d]imidazole/2-arylbenzo[d]oxazoles were prepared from the reaction between N-substituted-1,2-phenyldiamine/o-aminophenol and aroyl chlorides without adding any acid catalyst and organic solvents. The current work discloses, when increase the length of the alkyl chain on the imidazolinium ionic liquids correspondingly the product yields were raised, similarly, the different anions offered a different rate of reactivity as BF4− ∼ Br− > Cl− > PF6−. Further, we extended our studies to conduct the same reaction by the combination of ionic liquids as well as ultrasonication to produce superior results when compared to the simple conventional method. This methodology has the advantages of no usage of toxic catalysts and volatile organic solvents, yet a simple work-up procedure and high yields. Worthily, products can be separated from the ILs by ether and/or hexane solvent(s) washings. Convincingly, the catalyst could be recycled and reused for five cycles with no major loss in catalytic performance. Further, we confirm the stability of the recovered ionic liquids by the TGA and 1HNMR techniques. This system affords a green and improved protocol over the reporting methods.

Antiproliferative and Antiprostate Cancer Activities of Heterocyclic Compounds Derived from Cyclohexane-1,4-dione.

2-Amino-6-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (3) was prepared from the reaction of cyclohexane-1,4-dione with elemental sulfur and malononitrile in 1,4-dioxane and triethylamine as catalyst. The latter compound reacted with triethyl orthoformate and either malononitrile or ethyl cyanoacetate in 1,4-dioxane in the presence of triethylamine to produce 4H-thieno[2,3-f]chromene derivatives 10a,b. In addition, fused pyran and pyridine derivatives were synthesized starting from compound 3. The cytotoxicity of the synthesized compounds was studied on six cancer cell lines together with c-Met kinase and PC-3 cell line. The most active compounds were tested against five tyrosine kinases and Pim-1 kinase, most of which showed strong inhibition, encouraging further work.

A Novel Organometallic Coordination Polymer as a Heterogeneous Catalyst for C−C Bond Formation

One-pot solvothermal reaction of Ni(II) salt with 2-aminopyridine and thiethyl orthoformate in methanol afforded a novel one-dimensional nickel coordination polymer which can be regarded as a potential heterogeneous catalyst for nitroaldol (Henry) reaction.

Synthesis and pesticidal activity of new 1,3,4-oxadiazole thioether compounds containing a trifluoromethylpyrazoyl moiety

In order to find new lead compounds with high pesticidal activity, a series of 1,3,4-oxadiazole thioether compounds (5 series) were designed by using penthiopyrad as a synthon. They were synthesized easily via five steps by using ethyl 4,4,4-trifluoro-3-oxobutanoate and triethyl orthoformate as starting materials. The synthesized compounds were characterized by 1H NMR, 13C NMR and HRMS. The compound 2-(benzylthio)-5-(1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole (5a) was further determined by X-ray single-crystal diffraction. It crystallized in the monoclinic system, space group P21/c, Z = 4. All the 1,3,4-oxadiazole thioether derivatives were screened for fungicidal activity against ten fungi and herbicidal activity against two weeds. The bioassay results indicated that some of the synthesized 1,3,4-oxadiazole compounds exhibited good fungicidal activity (> 50% inhibition) against the plant pathogens Sclerotinia sclerotiorum and Rhizoctonia solani at 50 μg/mL. Some of them exhibited certain herbicidal activity, and compounds 2-((3-chlorobenzyl)thio)-5-(1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole (5e) and 2-((4-bromobenzyl)thio)-5-(1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole (5 g) had bleach effect. Molecular docking is to find the best fit orientation of the 2-((4-bromobenzyl)thio)-5-(1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-1,3,4-oxadiazole (5 g) molecule with the SDH protein (PDB: 2FBW). The docking results indicate that the compound 5 g and the lead compound penthiopyrad have similar binding interactions with SDH and carbonyl is a key group for these compounds.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11164-022-04839-x.