α-Halo Ketones in C-, N-, O-, and S-Alkylation Reactions

The review summarizes and analyzes both theoretical aspects and practical applications of C-, N-, O-, and S-alkylation with -halo ketones of aliphatic, alicyclic, aromatic, and heterocyclic compounds. Some reactions of -halo ketones with difunctional nucleophiles are also discussed.     

184(m,g)Re cross sections and isomeric ratios in181Ta(α, n) and W(α, pxn) reactions

Excitation functions and isomeric ratios for¹⁸⁴Re, from -induced reactions on¹⁸¹Ta and natural W have been measured using the stacked-foil method. The data are compared with the theoretical predictions provided by the equilibrium and pre-equilibrium reaction model; for this propose we used the code INDEX development by ERNST.     

O-烷基,O-芳基硫代磷酰取代硫脲和O-烷基硫代磷酰-双-取代硫脲的研究(Ⅱ)

用硫氰酸钾与硫代磷酰氯制备了硫代磷酰异硫氰基酯和二异硫氰基酯,并以其与不同胺反应,合成了硫代磷酰取代硫脲和硫代磷酰-双-取代硫脲两系列20个新的有机磷化合物,经1HNMR、IR及元素分析确定了它们的化学结构,测定了它们的生物活性。结果表明只有O-异丙基,O-(4-甲基-2-硝基苯基)-N''-萘基硫代磷酰硫脲(PD-1)具有较好的杀菌活性。     

Features of the reactions of β-aryl(heteryl)-α-nitroacrylates with N,N-, N,O-, and N,S-binucleophiles

The reactions of ??-aryl(heteryl)-??-nitroacrylates with N,N-, N,O-, and N,S-binucleophiles proceed regiospecifically through the initial formation of the Ad_N products, among which only the product from o-aminothiophenol was isolated. The conditions of converting the S-adducts into 2-aryl(heteryl)benzothiazole were found. The N-adducts formed in the reaction with hydrazine, o-phenylenediamine, and o-aminophenol undergo immediately the spontaneous transformation into the linear (azine, azomethine) or heterocyclic (benzimidazole) structures.     

O,O-(2,2’联苯基)二硫代磷酸酯及四(O,O-二烷基二硫代磷酰基)对-苯醌的合成

作者为了获得O,O-(2,2′-联苯基)二硫代磷酸酯及具有醌基的二硫代磷酸酯供试验其杀虫、杀菌活性之用,合成了上述两类新化合物共十六个。今将合成反应,操作手续及有关这些化合物的数值简报如下。 应用五硫化二磷和羟基化合物按文献一般方法制得了O,O-(2,2′-联苯基)二硫代磷酸及其酯十一个。     

Synthesis,characterization, and in vitro antibacterial and antifungal studies of tin(IV) thiohydrazide complexes

Reaction of tin dichloride and tin tetrachloride with cyclohexylamine-N-thiohydrazide (ChaThz) [L¹] and 1,3-propanediamine-N-thiohydrazide (PdaThz) [L²] results in [Sn(ChaThz)₂] (1), Sn(ChaThz)₂Cl₂] (2), [Sn(PdaThz)₂] (3), and [Sn(PdaThz)₂Cl₂] (4), in which the thiohydrazide coordinates to tin through imine nitrogen and thioamide sulfur. The ratio metal?:?ligand was 1?:?2 for all complexes. The tin(IV) thiohydrazide complexes were characterized by elemental analysis, IR, UV-Vis, ¹H-NMR, ¹¹⁹Sn NMR, and mass spectral studies. Using the disc diffusion method, the ligands and metal complexes were screened for in vitro antibacterial activities against four pathogenic bacteria, Escherichia coli, Staphylococcus aureus, P. aeruginosa, and Bacillus cereus and for antifungal activities against Aspergillus flavus, A. carbonarius, A. niger, and A. fumigatus. While the tin(IV) complexes exhibited moderate antifungal activities, their parent ligands showed much higher and long-lasting broad spectrum of bioactivity against fungal growth. This was particularly the case for L¹ whose fungal inhibitory activity by the end of the experimental period was comparable and, for the most part, more pronounced than that of AmB. This higher activity of L¹ was maintained specifically against S. Aureus but in general, bacteria were more susceptible to complexes than ligands.     

Studies on O-,N-Acylation of 3-Hydroxyisoxazole and Their Regioselective Synthesis(Ⅰ)——O-,N-acylation of 5-Methyl-3-hydroxyisoxazole with 2,2-Dimethyl 3-Substituted Cyclopropanecarboxylic Chlorides

The reactions of 5-methyl-3-hydroxyisoxazole with 2, 2-dimethyl, 3-substituted cyclopropanecarboxylic chlorides give O-acyl-5-methyl-3-hydroxyisoxazole and N-acyl-5-methylisoxazolin-3-one derivatives. The ratio of O-acyl to N-acyl product depends upon the acylation reagents. O-acyl derivatives can be converted to the N-acyl compounds by isomerization under acidic conditions or heating.     

Facile Syntheses of (±)-Curcuphenol, (±)-Curcudiol, (±)-Curcuhydroquinone,and (±)-Curcuquinone

The syntheses of (±)-curcuphenol 1, (±)-curcudiol 2, (±)-curcuhydroquinone 3, and (±)-curcuquinone 4 have been achieved. The key steps involved in the syntheses were the Reformatsky reaction and hydrogenation reaction.     

γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres: Preparation, formation mechanism, magnetic property, and application in water treatment

In this paper, we report the preparation of γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres by a solvothermal combined with precursor thermal conversion method. These γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres were constructed by three-dimensional self-assembly of nanosheets, forming porous nanostructures. The effects of experimental parameters including molar ratio of reactants and reaction temperature on the precursors were studied. The time-dependent experiments indicated that the Ostwald ripening was responsible for the formation of the hierarchically nanostructured hollow microspheres of the precursors. γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres were obtained by the thermal transformation of the precursor hollow microspheres. Both γ-Fe(2)O(3) and Fe(3)O(4) hierarchically nanostructured hollow microspheres exhibited a superparamagnetic property at room temperature and had the saturation magnetization of 44.2 and 55.4emu/g, respectively, in the applied magnetic field of 20 KOe. Several kinds of organic pollutants including salicylic acid (SA), methylene blue (MB), and basic fuchsin (BF) were chosen as the model water pollutants to evaluate the removal abilities of γ-Fe(2)O(3) and Fe(3)O(4) magnetic hierarchically nanostructured hollow microspheres. It was found that γ-Fe(2)O(3) hierarchically nanostructured hollow microspheres showed a better adsorption ability over SA than MB and BF. However, Fe(3)O(4) hierarchically nanostructured hollow microspheres had the best performance for adsorbing MB.     

Analysis of pigments and coverings by X-ray diffraction (XRD) and micro Raman spectroscopy (MRS) in the cemetery of Tutugi (Galera, Granada, Spain) and the settlement convento 2 (Montemayor, Córdoba, Spain)

This paper focuses on the identification of the composition of the coverings and pigments of two archaeological sites. The sites researched here lie in Andalusia and show two contexts, which have a highly symbolic and ritual meaning. The first, Convento 2 (Montemayor, Córdoba), dates back to the period of formation of the Iberian Culture (VIIth century b.c.). The second is the cemetery of Tutugi (Galera, Granada), of the mid-Iberian period (IVth century b.c.). The analytical procedure consisted in combined and complementary use of XRD and MRS. This allowed to identify the materials used, namely hematite, goethite, coal, gypsum and calcite. Identification of these materials proves essential for the restoration and musealization of both archaeological sites.     

Ion-Exchange Processes M(II) → Fe(III) and Fe(III) → M(II) in Metal Hexacyanoferrate(II) Gelatin-Immobilized Matrices (M = Mn,Co, Ni,Cu, Zn,Cd)

Ion-exchange reactions M²⁺ Fe³⁺ and Fe³⁺ M²⁺ (M = Mn, Co, Ni, Cu, Zn, Cd) were studied in metal(II) hexacyanoferrate(II) gelatin-immobilized matrices M₂[Fe(CN)₆] in contact with aqueous FeCl₃ solutions and Fe₄[Fe(CN)₆]₃ in contact with aqueous MCl₂ solutions. It was shown that in both cases, M²⁺ was replaced by Fe³⁺ and Fe³⁺ was replaced by M²⁺ to some extent, but no complete replacement was observed in the M₂[Fe(CN)₆]–FeCl₃ or Fe₄[Fe(CN)₆]₃–MCl₂ systems under study. No electrophilic substitution Fe³⁺ Mn²⁺ was found to occur in any noticeable degree during the contact of Fe₄[Fe(CN)₆]₃ with aqueous MnCl₂ solutions even when this contact occurred for 1 h and longer.     

Cross sections and isomeric ratios in197Au(α, 2pn)198(m,g)Au reactions

Excitation functions for the production of^198mAu,¹⁹⁸Au,^198(m+g)Au, by (, 2pn) reactions on gold and isomeric ratios for¹⁹⁸Au were determined experimentally. The method of activation of metallic foils was employed. The irradiations were performed in the isochronous cyclotron at Karlsruhe (Germany) with -particles at 90 MeV. Gamma-spectrometry by means of an intrinsic Ge detector was used to determine the nuclides produced. In addition, a comparison between the cross sections obtained and a calculation using the hybrid model of pre-equilibrium reactions, in combination with the statistical model development by ERNST is presented.     

Coordination bonding in dicopper and dichromium tetrakis(μ-acetato)-diaqua complexes: Nature,strength, length,and topology

Geometry optimization, energetics, electronic structure, and topology of electron density of dicopper ( I ) and dichromium ( II ) tetrakis(μ-acetato)-diaqua complexes are studied focusing on the metal–metal interactions. The performance of broken symmetry (BS) single-determinant ab initio (Hartree–Fock, Møller–Plesset perturbation theory to the second and third orders, coupled clusters singles and doubles) and density functional theory (BLYP, B3LYP, B3LYP-D3, B2PLYP, MPW2PLYP) methods is compared to multideterminant ab initio (CASSCF, NEVPT2) methods as well as to the multipole model of charge density from a single-crystal X-ray diffraction experiment (Herich et al., Acta Cryst. 2018, B74, 681–692). In vacuo DFT geometry optimizations (improper axial water ligand orientation) are compared against the periodic ones. The singlet state is found to be energetically preferred. J coupling of ( I ) becomes underestimated for all ab initio methods used, when compared to experiment. It is concluded that the strength of the direct M─M interactions correlates closely with the J coupling magnitude at a given level of theory. The double potential well character of (II) and of the dehydrated form of (II) are considered with respect to the Cr─Cr distance. The physical effective bond order of the metal–metal interaction is small (below 0.1 e) in ( I ) and moderate (0.4 e) in ( II ). The CASSCF results overestimate the electron density of the metal–metal bond critical point by 20% and 50% in ( I ) and ( II ), respectively, when compared to the multipole model. © 2019 Wiley Periodicals, Inc.     

Complexation between Iron(III) and β-Hydroxyethylimino-N,N-Diethanoic and Dicarboxylic Acids in Aqueous Solutions

The reactions of iron(III) with -hydroxyethylimino-N,N-diethanoic acid (H₂Heida) and dicarboxy-lic acids (oxalic (H₂Ox), malonic (H₂Mal), and succinic (H₂Suc)) are studied using the spectrophotometric method. The equilibrium pattern in the binary and ternary systems is investigated. The complexation processes were shown to be complicated by hydrolysis and to depend strongly on the acidity of the medium. The following complexes were detected: FeHeida⁺, Fe(OH)Heida, Fe(OH)₂Heida^–, Fe(Heida)Ox^–, Fe(OH)(Heida)Ox^2–, Fe(OH)₂(Heida)Ox^3–, Fe(Heida)Mal^–, Fe(OH)(Heida)Mal^2–. Logarithms of the stability constants of these complexes calculated at = 0.1 (NaClO₄) and T = 20 ± 2°C are equal to 11.64 ± 0.05, 22.97 ± 0.05, 31.17 ± 0.05, 18.83 ± 0.03, 28.27 ± 0.02, 36.14 ± 0.02, 17.64 ± 0.03, and 26.39 ± 0.03, respectively.     

Total synthesis of (±)-maistemonine, (±)-stemonamide, and (±)-isomaistemonine

A full account of the total synthesis of (±)-maistemonine, (±)-stemonamide, and (±)-isomaistemonine is presented. Two approaches have been developed to construct the basic pyrrolo[1,2-a]azepine core of the Stemona alkaloids, featuring a tandem semipinacol/Schmidt rearrangement of a secondary azide and a highly stereoselectively desymmetrizing intramolecular Schmidt reaction, respectively. To build the common spiro-γ-butyrolactone, a new protocol was carried out by utilizing an intramolecular ketone-ester condensation as the key transformation. The vicinal butyrolactone moiety of (±)-maistemonine was stereoselectively introduced via a one-pot procedure involving the epimerization at C-3 and carbonyl allylation/lactonization. Moreover, (±)-stemonamide was divergently synthesized from a common intermediate, and (±)-isomaistemonine was obtained via the epimerization of (±)-maistemonine at C-12.     

Electronic properties and charge transfer phenomena in Pt nanoparticles on γ-Al(2)O(3): size, shape, support, and adsorbate effects

This study presents a systematic detailed experimental and theoretical investigation of the electronic properties of size-controlled free and γ-Al(2)O(3)-supported Pt nanoparticles (NPs) and their evolution with decreasing NP size and adsorbate (H(2)) coverage. A combination of in situ X-ray absorption near-edge structure (XANES) and density functional theory (DFT) calculations revealed changes in the electronic characteristics of the NPs due to size, shape, NP-adsorbate (H(2)) and NP-support interactions. A correlation between the NP size, number of surface atoms and coordination of such atoms, and the maximum hydrogen coverage stabilized at a given temperature is established, with H/Pt ratios exceeding the 1?:?1 ratio previously reported for bulk Pt surfaces.     

Avoided crossings in metal (M)–gas (X) reactions (M = Hg, and X = SiH4, GeH4)

A study of nonadiabatic transitions through avoided crossings between two potential energy curves, associated to the approach of a mercury atom to an organic gas molecule (silane or germane) is presented. We study the Si–H and Ge–H bond breaking in the molecules SiH₄ and GeH₄, which are an important subject in the production of hydrogenated amorphous thin films. We here emphasize the importance of the excited states, the avoided crossings generated during the molecule–metal approach and the nonadiabatic transition probabilities. We have developed a model to extend the Landau–Zener theory utilizing the angle instead of the distance as the main parameter of the reaction, which is particularly adapted for tetrahedral molecules (as silane and germane). The activation process of these molecules requires several stages; first, we solve the Schrödinger equation (within the Born-Oppenheimer approximation) for the metal–molecule system during interaction. We always take into account all those states that can play a role in the reaction, even those that because of their energetic separation from the ground state are forgotten by other groups. The calculations begin at a LCAO-MO approximation and thenceforth variational and perturbative CI including of the order of a million determinants are carried out. Usually, some states of the metal repel the gas molecule and others attract it. This produces a series of avoided crossings among the curves, demanding that the nonadiabatic transition probabilities are obtained. This is the ultimate goal of the present study.     

相转移催化合成O,O-二芳基(硫代)磷酰氯

用０．０５ｍｏｌ三氯硫磷和０．１０ｍｏｌ的酚通过相转移催化反应合成Ｏ,Ｏ-二芳氧基硫代磷酸氯可得较好收率。产物经ＩＲ和１ＨＮＭＲ表征。     

Condensation of 2-alkoxypropenals with N,N- and N,O-1,2-binucleophiles. A route to 2-(1′-alkoxyvinyl)imidazo-lidines and -oxazolidines

Condensation of 2-ethoxypropenal with diaminoethylene in different solvents (CHCl₃, MeCN, H₂O, DMSO) at room temperature gives an equilibrium mixture (1:1–1.5) of tautomeric 2-(1′-ethoxyvinyl)-1,3-imidazolidine and 2-aminoethylimine of 2-ethoxypropenal as well as 1,2-bis(2′-ethoxypropenyl-ideneamino)ethylene. The latter is readily prepared in quantitative yield using a twofold excess of the aldehyde. ¹H NMR was used to demonstrate the effect of heating on the dynamics of the ring-chain tautomeric equilibrium. Reaction of the 2-alkoxypropenals with N-methyl- and N,N′-diphenyl-1,2-diaminoethylenes and with N-phenylaminoethanol gives only the corresponding substituted imidazolidines in 43–95% yield. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov in his 70^th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1809–1815, December, 2008.     

Independent isomeric yield ratios of 95m,gNb in the natMo(γ, pxn) and natZr(p,xn) reactions

The independent isomeric yield ratios of ^95m,gNb from the ^natMo(γ, pxn) reactions with bremsstrahlung end-point energies of 45, 50, 55, 60, and 70 MeV were determined by an activation and an off-line γ-ray spectrometric technique at the Pohang accelerator laboratory (PAL), Korea. The isomeric yield ratios of ^95m,gNb from the ^natZr(p, xn) reactions were also determined in eight different proton energies within 19.4–44.7 MeV by a stacked-foil activation and an off-line γ-ray spectrometric technique using the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences (KIRAMS), Korea. The measured isomeric yield ratios of ^95m,gNb from the present work and the literature data in the ^natMo(γ, pxn) and ^natZr(p, xn) reactions were compared with the similar literature data in the ^natMo(p, αxn) reactions. It was found that the isomeric yield ratio of ^95m,gNb increases with projectile energy, which indicate the effect of excitation energy. However, at the same excitation energy, the isomeric yield ratios of ^95m,gNb in the ^natZr(p, xn) and ^natMo(p, αxn) reactions are higher than those in the ^natMo(γ, pxn) reaction, which indicates the role of input angular momentum. The isomeric yield ratios of ^95m,gNb in the ^natMo(γ, pxn), ^natZr(p, xn), and ^natMo(p, αxn) reactions were also calculated using computer code TALYS 1.4. The calculated isomeric yield ratios of ^95m,gNb from three reactions increase with excitation energy. However, in all the three reactions, the calculated values are significantly higher than the experimental data.