Synthesis,structure and cytotoxic activity of 2‐acetyl‐5‐trimethylsilylthiophene(furan) and their oximes

5‐Trimethylsilylderivatives of 2‐acetylthiophene and ‐furan have been regioselectively prepared by a one‐pot procedure from the corresponding 2‐acetylfuran or 2‐acetylthiophene using lithium N‐methylpiperazide (LNMP)–butyllithium–trimethylchlorosilane–water as the sequence of reagents. The ketones obtained were converted to the corresponding oximes. The structure of 2‐acetyl‐5‐trimethylsilylthiophene oxime (E‐isomer) has been studied by X‐ray diffraction. Formation of centrosymmetric dimers by means of H‐bonds has been observed. The intermolecular hydrogen bond O9? H…N8 length is 2.842(5) Å [H…N8 = 1.87 (6) Å, O9? H…N8 = 157(4)°]. Copyright © 2006 John Wiley & Sons, Ltd.     

Synthesis of Polysubstituted Benzenes via the Vinylogous Michael Addition of Alkylidenemalononitriles to 2‐(1,3‐Dioxo‐1H‐inden‐2(3H)‐ylidene)malononitrile

An efficient synthesis for polysubstituted benzenes was successfully developed by the reaction of ninhydrin (=2,2‐dihydroxyindane‐1,3‐dione), malononitrile (=propanedinitrile), and alkylidenemalononitrile. The method involves vinylogous Michael addition of alkylidenemalononitrile to 2‐(1,3‐dioxo‐1H‐inden‐2(3H)‐ylidene)malononitrile, which formed by condensation of malononitrile and ninhydrin in the presence of Et₃N, and the alcoholic solvent has participated in the reaction as a reagent. The method has the advantages of good yields and of not requiring a metal catalyst. The structures were confirmed spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses, and, in the case of 2c , by X‐ray crystallography. A plausible mechanism for this reaction is proposed (Scheme).     

A New and Convenient Synthesis of Amino‐phthalimide (1H‐Isoindole‐1,3(2H)‐dione) Derivatives and Their Photoluminescent Properties

A new and convenient synthesis for amino‐phthalimide (1H‐isoindole‐1,3(2H)‐dione) derivatives has been developed starting from an α,β‐unsaturated ketone. The ketones were reacted with amines to give aromatic amine products. This is the first time that substituted amine groups have been incorporated in aromatic rings. The mechanism of the product formation is rationalized by the 1,2‐addition of amines to ketones. All aromatic compounds exhibited high fluorescence properties at the blue‐green region.     

Design,Synthesis and Herbicidal Activities of Tetrahydroisoindoline‐1,3‐dione Derivatives Containing Alkoxycarbonyl Substituted 2‐Benzoxazolinone

Several different alkoxycarbonyl‐substituted 2‐benzoxazolinone moieties have been incorporated into a tetrahydroisoindoline‐1,3‐dione scaffold to provide 25 compounds ( 1a – 1u and 2a – 2d ). The structures of these compounds were confirmed by ¹H and ¹³C NMR, HRMS and X‐ray single‐crystal diffraction. Some of these compounds ( 1g , 1h , 1j , 1k ) exhibited excellent herbicidal activities against Abutilon theophrasti, Amaranthus retroflexus and Echinochloa crus‐galli at a rate of 375 g AI·ha^?1. Among them, compounds 1h and 1j displayed the best post‐emergence herbicidal effect against Abutilon theophrasti with ED₅₀ values of 1.8 and 5.3 g AI·ha^?1, respectively, which are superior to that of the commercial acifluorfen (44.3 g AI·ha^?1). Field trials demonstrated that compound 1h exhibited similar herbicidal activity to a high concentration atrazine, and found to be safer for maize than atrazine. The results of this study therefore show that compound 1h could potentially be used as a post‐emergence herbicide for maize fields.     

Five Coordinated Zinc(II) and Tris‐Chelate Cadmium(II) Complexes with 2,2′‐Diamino‐5,5′‐dimethyl‐4,4′‐bithiazole – Syntheses,Spectroscopic Characterization,and Crystal Structure

The new synthesized ligand (DADMBTZ = 2,2′‐diamino‐5,5′‐dimethyl‐4,4′‐bithiazole), which is mentioned in this text, is used for preparing the two new complexes [Zn(DADMBTZ)₃](ClO₄)₂. 0.8MeOH.0.2H₂O ( 1 ) and [Cd(DADMBTZ)₃](ClO₄)₂ ( 2 ). The characterization was done by IR, ¹H, ¹³C NMR spectroscopy, elemental analysis and single crystal X‐ray determination. In reaction with DADMBTZ, zinc(II) and cadmium(II) show different characterization. In 2 , to form a tris‐chelate complex with nearly C₃ symmetry for coordination polyhedron, DADMBTZ acts as a bidentate ligand. In 1 , this difference maybe relevant to small radii of Zn²⁺ which make one of the DADMBTZ ligands act as a monodentate ligand to form the five coordinated Zn²⁺ complex. In both 1 and 2 complexes the anions are symmetrically different. 1 and 2 complexes form 2‐D and 3‐D networks via N‐H···O and N‐H···N hydrogen bonds, respectively.     

Synthesis and Hill Inhibitory Activity of New Substituted 3‐Aryl‐5‐cyano‐6‐methylthio Pyrimidine‐2, 4‐diones

Novel substituted derivatives of 3‐aryl‐5‐cyano‐6‐methylthiopyrimidine‐2, 4‐diones were synthesized by the reaction of ethyl 2‐cyano‐3,3′‐dimethylthioacrylate with arylureas in good yields. The structures of all title compounds were evaluated by elemental analyses and ¹H NMR spectra and compound 2c was also confirmed by X‐ray diffraction. Hill reaction inhibitory activity of title compounds was assayed.     

Synthesis, spectroscopic and DFT investigation of dimethyl-2-(5-acetyl-2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-3-(triphenylphosphinylidene)succinate

Dimethyl-2-(5-acetyl-2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-3-(triphenylphosphinylidene)succinate has been synthesized and characterized by elemental analysis, FT-IR and ¹H, ¹³C and ³¹P NMR. The vibrational wavenumbers, gauge including atomic orbital (GIAO) ¹H and ¹³C chemical shift values of title compound in the ground state have been computed with density functional theory method (DFT) and the B3LYP functional. The basis sets used are 6-311G(d,p) and 6-31G(d). The harmonic vibrational wavenumbers have been computed and the scaled values have been compared with the experimental FT-IR spectra. The complete assignments have been performed on basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Most of the computed wavenumbers are found to be in good agreement with the observed spectrum.     

Synthesis of [3,3′(4H,4′H)‐Bi‐2H‐1,3‐oxazine]‐4,4′‐diones and Their Hydrolysis

The [3,3′(4H,4′H)‐bi‐2H‐1,3‐oxazine]‐4,4′‐diones 3a – 3i were obtained by [2+4] cycloaddition reactions of furan‐2,3‐diones 1a – 1c with aromatic aldazines 2a – 2d (Scheme 1). So, new derivatives of bi‐2H‐1,3‐oxazines and their hydrolysis products, 3,5‐diaryl‐1H‐pyrazoles 4a – 4c (Scheme 3), which are potential biologically active compounds, were synthesized for the first time.     

Synthesis and functionalization of Poly[5,5′‐(silylene)‐2,2′‐dithienylene]s using silyl triflate intermediates†

Treatment of 5,5′‐dilithio‐2,2′‐dithiophene with (dimethylamino)methylsily bis(triflate)‐ or α, ω‐bis(triflate)‐substituted trisilanes gave poly[5,5′‐(silylene)‐2,2′‐dithienylene]s in high yields. The amino–silyl bond was cleaved selectively by triflic acid, leading to triflate‐substituted derivatives. Conversion of these compounds with nucleophiles gave other functionalized polymers. Platinum‐catalyzed hydrosilylation reactions between silicon–vinyl and silicon–hydrogen derivatives result in polymer networks which may serve as interesting preceramic materials. The structures of the polymers were proven by NMR spectroscopy (²⁹Si, ¹³C, ¹H). Results of thermal gravimetric analysis (TGA), UV spectrometry and conductivity measurements are given. Copyright © 1999 John Wiley & Sons, Ltd.     

N-(4-甲基苯甲酰氨基) N’-[5-(2-三氟甲基苯基)-2-呋喃甲酰硫脲的合成、晶体结构测定与生物活性测定

本文首次合成标题化合物N-(4-甲基苯甲酰氨基)-N’-[5-(2-三氟甲基苯基)-2-呋喃甲酰硫脲。化合物(C21H16F3N3O3S, Mr = 447.43)单晶经测定为单斜晶体,空间群为P -1。在晶体中,存在一些分子内和分子间的相互作用,分子间还有C—H···π 的相互作用,这可能导致晶体更稳定的原因。目标产物的结构经IR, H NMR和元素分析测定确证。初步生物活性测试表明,部分化合物对棉花枯萎病、黄瓜灰霉病、苹果轮纹病和棉花炭疽病有较好的选择性杀菌活性;部分目标化合物有较好的除草活性。     

Synthesis,crystal structure and magnetic properties of (acetato‐κ2O,O′)bis(5,5′‐dimethyl‐2,2′‐bipyridine‐κ2N,N′)nickel(II) perchlorate monohydrate

The title hydrated ionic complex, [Ni(CH₃COO)(C₁₂H₁₂N₂)₂]ClO₄·H₂O or [Ni(ac)(5,5′‐dmbpy)₂]ClO₄·H₂O (where 5,5′‐dmbpy is 5,5′‐dimethyl‐2,2′‐bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate–5,5′‐dmbpy–KClO₄ system. Within the complex cation, the Ni^II atom is hexacoordinated by two chelating 5,5′‐dmbpy ligands and one chelating ac ligand. The mean Ni—N and Ni—O bond lengths are 2.0628 (17) and 2.1341 (15) Å, respectively. The water solvent molecule is disordered over two partially occupied positions and links two complex cations and two perchlorate anions into hydrogen‐bonded centrosymmetric dimers, which are further connected by π–π interactions. The magnetic properties of (1) at low temperatures are governed by the action of single‐ion anisotropy, D, which arises from the reduced local symmetry of the cis‐NiO₂N₄ chromophore. The fitting of the variable‐temperature magnetic data (2–300 K) gives g_iso = 2.134 and D/hc = 3.13 cm⁻¹.     

An Efficient Synthesis of 3,3′,4,4′‐Tetrahydro‐4,4′‐bibenzo[e][1,3]oxazine‐2,2′‐dione Derivatives with the Aid of Low‐valent Titanium

Synthesis of 3,3′,4,4′‐tetrahydro‐4,4′‐bibenzo[e][1,3]oxazine‐2,2′‐diones via reaction of salicylidendphenylhydrazone and triphosgene with the aid of low‐valent titanium reagent is described. This method has the advantages of accessible starting materials, good yields and short reaction time.     

Synthesis of Dispiro[indole‐3,2′‐pyrrolidine‐3′,2″‐pyrrolizine]‐1″,2(1H)‐diones via Azomethine Ylide 1,3‐Dipolar Cycloaddition

The 1,3‐dipolar cycloaddition of azomethine ylide generated in situ from isatin and sarcosine to 2‐arylmethylidene‐2,3‐dihydro‐1H‐pyrrolizin‐1‐ones afforded novel 1′‐methyl‐4′‐(aryl)‐1″H‐dispiro[indole‐3,2′‐pyrrolidine‐3′,2″‐pyrrolizine]‐1″,2(1H)‐diones in good yields. The structures of all the products were characterized thoroughly by NMR, infrared spectroscopy, mass spectrum, and elemental analysis.     

Mechanism of the Reaction of Amines with 5‐[(Aryl‐ or Alkylamino)hydroxymethylene]‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐diones in the Presence of Chlorotrimethylsilane (Me3SiCl)

Addition of chlorotrimethylsilane (Me₃SiCl) to the mixture of a carbamoyl‐substituted Meldrum's acid, i.e., a 5‐[(arylamino)hydroxymethylene]‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione of type 1 and a secondary amine as nucleophile strongly accelerated the rate of their reaction. The reason for this phenomenon observed, during our previous research, remained, however, unclear. To elucidate the mechanism of this reaction, we assumed and verified three possible pathways for the action of Me₃SiCl (cf. Scheme 2): The acceleration of the reaction is caused i) by formation of a O‐trimethylsilylated Meldrum's acid of type 2 , ii) by the silylated amine 3 , or iii) by the presence of HCl liberated from Me₃SiCl. The performed experiments revealed that the faster course of reaction is caused by the formation of N‐trimethylsilylated amines of type 3 .     

Synthesis,structure and biological activity of new 6,6‐dimethyl‐2‐oxo‐4‐{2‐[5‐organylsilyl(germyl)]furan(thiophen)‐2‐yl}vinyl‐5,6‐dihydro‐2H‐pyran‐3‐carbonitriles

New 6,6‐dimethyl‐2‐oxo‐4‐{2‐[5‐alkylsilyl(germyl)]furan(thiophen)‐2‐yl}vinyl‐5,6‐dihydro‐2H‐pyran‐3‐carbonitriles (IC₅₀: 1–6 µg ml^?1) have been prepared by the condensation of corresponding silicon‐ and germanium‐containing furyl(thienyl)‐2‐carbaldehydes with 3‐cyano‐4,6,6‐trimethyl‐5,6‐dihydropyran‐2‐one using piperidine acetate as a catalyst. The obtained carbonitriles were identified using NMR (¹H, ¹³C and ²⁹Si) spectroscopy and GC‐MS. The structure of 6,6‐dimethyl‐2‐oxo‐4‐[2‐(5‐trimethylsilyl)thiophen‐2‐yl]‐5,6‐dihydro‐2H‐pyran‐3‐carbonitrile was studied using X‐ray diffractometry. The influences of the heterocycle and the structure of the organoelement substituent on cytotoxicity and on matrix metalloproteinase inhibition have been studied. Copyright © 2015 John Wiley & Sons, Ltd.     

Iodine‐Catalyzed Synthesis of Spiro[1,3,4‐benzotriazepine‐2,3′‐indole]‐2′,5(1H,1′H)‐diones under Mild Conditions

The I₂‐catalyzed preparation of spiro[1,3,4‐benzotriazepine‐2,3′‐indole]‐2′,5(1H,1′H)‐diones from 2‐aminobenzohydrazide and isatins in MeCN at room temperature in good‐to‐excellent yields is described. The structure of 3 was corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS data). A plausible mechanism for this type of reaction is proposed (Scheme 2).     

On the Reactions of Furan‐2,3‐diones with Oxindole (=1,3‐Dihydro‐2H‐indol‐2‐one) and Lawesson Reagent. Synthesis of New 1,3‐Dihydro‐2H‐indol‐2‐ones,Bis‐furanones,and Bis‐pyrrolones

Lactone analogues of 3‐substituted oxindoles (=1,3‐dihydro‐2H‐indol‐2‐ones) and nonbenzoid oxa‐analogous isoindigoid or nonbenzoid isoindigoid dyes were prepared by the reactions of furan‐2,3‐diones with oxindole and Lawesson reagent (Schemes 1 and 3), respectively. So, new derivatives of 2‐oxobutanoic acid, bis‐furanone, and bis‐pyrrolone, which are potentially biologically active compounds, were synthesized for the first time.     

DFT Calculations,Spectroscopic Studies,Biological Activity and Non Linear Optical Properties (NLO) of Novel Ternary Cu(II)‐Chelates Derived from 5‐Acetyl‐4‐hydroxy‐2H‐1,3‐thiazinedione

New ternary Cu(II)‐chelates with the general formula [ML L′(H₂O)_x] (NO₃)_y x (H₂O), x = 0–2 and y = 0–1, (L) = 5‐acetyl‐4‐hydroxy‐2H‐1,3‐thiazine‐2,6(3H)‐dione with in the presence of a secondary ligand (L′) [N,O‐donor; 8 hydroxyquinoline or N,N‐donor; 1,10‐phenanthroline and diethethylendiamine]. Characterization of the synthesized complexes was established based on elemental analysis, molar conductance, magnetic susceptibility measurements, spectral (infrared, electronic, mass, ¹H‐NMR and ESR) as well as thermal gravimetric analysis (TGA). The complexes exhibited octahedral and square planer geometry. The antimicrobial activity for the studied complexes was tested for different kind of organisms. The geometrical and non‐linear optical parameters of the studied complexes 1–3 are investigated theoretically at the B3LYP/GENECP level of theory. The optimized geometries of the studied complexes are non‐planner as indicated from the dihedral angles. The natural charge population (core, valence and Rydberg), exact electronic configuration, total Lewis, and total non‐Lewis is computed and discussed in terms of natural bond orbitals (NBO) analysis. The calculated E_HOMO and E_LUMO energies at the same level of theory of the studied complexes were used to calculate the global properties; hardness (η), global softness (S), electrophilicity (ω) and electronegativity (χ). The total dipole moment (μ_tot), total and anisotropy of polarizability (? α ?), (Δα) and first hyperpolarizability (? β ?) values were calculated and compared with urea as a reference compound. From the values of the computed first hyperpolarizability (? β ?), the ligand and the studied complexes show promising optical properties.     

Antitumour activity of synthetic curcuminoid analogues (1,7‐diaryl‐1,6‐heptadiene‐3,5‐diones) and their copper complexes

Four new curcuminoid analogues, 1,7‐bis(4‐hydroxyphenyl)‐1,6‐heptadiene‐3,5‐dione, 1a ; 1,7‐di(2‐furyl)‐1,6‐heptadiene‐3,5‐dione, 1b ; 1,7‐di(2‐naphthyl)‐1,6‐heptadiene‐3,5‐dione, 1c ; 1,7‐bis(2‐chlorophenyl)‐1,6‐heptadiene‐3,5‐dione, 1d ; and their copper(II) complexes of ML₂ stoichiometry were synthesized and characterized by UV, IR, ¹H NMR, ESR and mass spectral data. The compounds were investigated for their possible cytotoxic and antitumour activities. It was found that copper chelates are remarkably active compared with free curcuminoid analogues. All the compounds were found to be cytotoxic towards Ehrlich ascites carcinoma cells and cultured L929 (lung fibroblast cells). In the case of culture studies, concentrations needed for 50% cell death were around 5 µg/ml for copper complexes and 10 µg/ml for curcuminoid analogues. Copper complex of 1a with hydroxyl group in the phenyl ring was found to be most active towards L929cells (1 µg/ml produced 43.3 ± 1.3% cell death). Compound 1b , which possesses a furyl ring system, was found to show least activity towards increase in life span of tumour‐bearing mice (increase in life span 39.31%). Copper chelates of all curcuminoid analogues showed a significant reduction (p < 0.001) of solid tumour volume in mice. Copyright © 2005 John Wiley & Sons, Ltd.