Presence Of Copper Chloride Research Articles

Copper Loading-Controlled Selective Synthesis of 2,5-Bis(trifluoromethyl) and Monotrifluoromethyl-Substituted Oxazoles.

A general domino annulation reaction of sulfonylmethyl isocyanide with trifluoroacetic anhydride in the presence of copper chloride as an additive is developed. The reaction affords 2,5-bis(trifluoromethyl)oxazoles in modest to good yields under mild conditions. A wide variety of sulfonylmethyl isocyanide and perfluorocarboxylic anhydride substrates are amenable to this transformation. Under a higher copper salt loading conditions, the reaction led to the formation of monotrifluoromethyl-substituted oxazole product.

Synthesis of functionalized alkenes via Cu(I)-catalysed allylation of acetanilides using Morita-Baylis-Hillman bromides.

An easy access to functionalized alkenes has been developed by the C-H functionalization of anilides with Morita-Baylis-Hillman (MBH) bromides in the presence of copper chloride, TBHP and acetic acid. Unsubstituted as well as ortho/meta-substituted anilides exclusively give rise to the para-allylated products, whereas para-substitution brings about the formation of ortho-allylated anilides.

Secondary metabolite from <em>Pseudomonas aeruginosa</em> LV strain exhibits antibacterial activity against <em>Staphylococcus aureus</em>

This study aimed to evaluate the antibacterial activity of the dichloromethane/ethyl acetate fraction (named F4a), obtained from the culture of Pseudomonas aeruginosa LV strain in presence of copper chloride, against planktonic and sessile cells of Staphylococcus aureus, including those presenting multidrug resistance. First, the minimal inhibitory concentrations (MIC) of F4a for twenty-six clinical isolates were determined and the values ranged from 1.56 to 6.25 µg/mL. Minimal bactericidal concentration (MBC) of 3.13 µg/mL was detected in 84.6% of the isolates. The time-kill curve analysis revealed a significant decreased in colony-forming unit counts after 4 h of treatment with the MIC/MBC of F4a. Moreover, the MIC/MBC of the fluopsin C, a copper-containing compound present in F4a, were 1.56/3.13 µg/mL, indicating that this compound seems to be one of the active components related to the antibacterial activity against S. aureus. Images of transmission electron microscopy showed significant ultrastructural alterations in planktonic cells treated with the MIC/MBC of F4a. A significant reduction in the metabolic activity of established biofilms of all S. aureus isolates was observed after treatment with F4a. No hemolytic activity to human erythrocytes was detected for F4a, and the cytotoxic concentration to LLC-MK2 cells was 3.44 µg/mL. In conclusion, F4a exhibited a bactericidal activity against planktonic cells and inhibited the metabolic activity of biofilms of S. aureus. F4a can be promising for the development of new strategies for the treatment of infections caused by S. aureus.

Synthesis, characterization and evaluation of optical band gap of new semiconductor polymers with N-aryl- 2,5-diphenyl-pyrrole units

• New polymers containing pyrrole fragments were synthesized and fully characterized. • Pyrrole fragments of polymers obtained have electron withdrawing groups. • New polymers were obtained by chemical modification by the reisch-Shulte reaction. • The polymers obtained are potential organic materials with semiconductor behavior. We used chemical modification to obtain new polymers that contain pyrrole units in the main chain, with electron-withdrawing groups acting as potential organic semiconductors, by means of chemical modification of the diacetylene-containing precursors. These were prepared by oxidative coupling of terminal diacetylenes or by superelectrophilic polycondensation of diphenoxydiacetylene with isatin. Diacetylenic fragments in the precursors reacted with aromatic amines that bore electron-withdrawing substituents in the presence of copper chloride, in order to yield the corresponding diphenyl-pyrrole polymers. These were then fully characterized by NMR, IR and thermal analysis. The molecular weights of the polymers were also determined by GPC. We used UV–vis spectroscopy to derive the optical band gap of the polymers. The band gap values of synthetized polymers can be modulated by modifying the position and type of substituent. Band gaps obtained in wafer form range from 1.35 to 2.8 eV; the range required for polymer semiconductors, if they are to be employed in optoelectronic devices.

Notoginseng-derived B/N co-doped porous carbon with high N-doped content and good electrochemical performance

Biomass is regarded as the ideal carbon sources for the preparation of porous carbons owing to its abundance, environmental friendliness, and facile availability. Herein a novel biomass, notoginseng, is used as the carbon source for synthesizing a novel B/N co-doped porous carbon (BNC) via one-step carbonization/activation procedure with the presence of copper chloride and boric acid. It is found that utilization of copper chloride and boric acid to fulfill one-step activation not only promotes the fixation of heteroatom-containing species but also facilitates formation of abundant micropores and mesopores in the carbon matrix. The as-prepared BNC sample thus exhibits developed porosity, large specific surface area (982 m2 g–1), and plentiful heteroatom dopants (e.g., N, 10.51 at.%; O, 15.38 at.%; B, 0.7 at.%). Investigation of supercapacitive performance reveals that the BNC electrode holds a delightful capacitance of 261 F g–1 at 0.5 A g–1 and a good rate capacitance of 172.8 F g–1 at 10 A g–1 in 6 M KOH electrolyte; and its symmetric supercapacitor exhibits excellent cyclic performance (capacitance retention, 93.2%) during 10,000 cycles at 5 A g–1, and a moderate energy output of 6.16 W h kg–1 at 100.12 W kg–1. These findings indicate that the notoginseng-derived porous carbon is a promising electrode material for supercapacitors due to its simple preparation method and superior electrochemical performance.

Copper catalyzed N-arylation of sulfoximines with aryldiazonium salts in the presence of DABCO under mild conditions

N-Arylation of sulfoximines with aryldiazonium tetrafluoroborates is demonstrated in the presence of copper chloride and DABCO. A wide range of aryl and alkyl sufoximines are participated in the coupling reaction with different aryldiazonim salts bearing electron donating and withdrawing groups and provided the desired products in 67–88% yields. The reaction proceeds through a radical mechanism.

Synthesis of norbornene/divinylbenzene copolymers catalyzed by anilinonaphthoquinone‐ligated nickel complexes and their applications for the synthesis of graft polymers

AbstractThe copolymerization of norbornene (NB) and divinylbenzene (DVB) was carried out using anilinonaphthoquinone‐ligated nickel complexes of the type [Ni(C10H5O2NAr)(Ph)(PPh3)] (1a: Ar = C6H3‐2,6‐ iPr; 1b: Ar = C6H2‐2,4,6‐Me; 1c: Ar = C6H5) with modified methylaluminoxane (MMAO) as a cocatalyst. The DVB content was varied (5–25 mol%) and the resulting copolymers exhibited number‐average molecular weights (Mn) of 40,000–69,000 g/mol with polydispersities (PDI = 1.5–1.8). The styryl group of the NB/DVB copolymer was used for grafting poly(methyl methacrylate) by reverse atom transfer radical polymerization using azobisisobutyronitrile in the presence of copper chloride and bipyridine.

Arylsulfonylation of phenylacetylene. Synthesis a-chlorostyrylarylsulfones

One-step method for the synthesis of a-chlorostyryl arylsulfones by the interaction of phenylacetylene with arenediazonium salts and sulfur dioxide(IV) in the presence of copper chloride(II) have been presented. The yields of 1-chloro-1-phenyl-2-arylsulfonylethene are 50–73 %. In the case of using equimolar quantities of reagents, the degree of conversion of the monomer does not exceed 50 %. Ar = C 6 H 5 ; 4-CH 3 C 6 H 4 ; 4-CH 3 OC 6 H 4 ; 4-NO 2 C 6 H 4 ; 4-BrC 6 H 4 It was investigated the role of solvents in this reaction. Conducting the reaction in aqueous acetic acid leads to the formation of a mixture of E - and Z -isomeric products. It was founded that in water – acetone medium reaction is stereoselective as a trans -addition of arylsulfonyl-group and chloro-atom to triple bound. E -α-chlorostyrylarylsulfonts are formed. 1 H NMR data for E -a-chlorostyrylarylsulfones were obtained. It was proposed a SET mechanism of this reaction which include participation Cu + D Cu 2+ catalityc redox system. Under the action of a catalyst, the cation-radical of phenylacetylene formed and reacted with arylsulfonyl-radical, generated in the catalytic reaction of aryldiazonium-cation with SO 2 . This leads to formation of arylsulfovinyl-cation. The latter stabilization is possible through complexation with a catalyst. The complex fixes the configuration of the ethylene fragment, which leads to the chloride-ion rear attack, and provides a high stereoselectivity of the reaction of arylsulfonylation of phenylacetylene with aryldiazonium salts and SO 2 and the formation of E-α-chlorostyrylsulfones. It is obvious that the use of acetone-water (1 : 1) as a solvent contributes to the stabilization of the complex. The intermediate complex formation provide the stereoselectivity of this reaction. Keywords : chlorostyrylarylsulfones, arylsulfonylation, aryldiazonium salts, phenylacetylene, copper-catalysis.

Advanced panel training on visual Gestalt evaluation of biocrystallization images: ranking wheat samples from different extract decomposition stages and different production systems

ABSTRACTBiocrystallization images are formed in reaction with foods; in the course of the evaporation of the water from food extracts in presence of copper chloride, crystalline structures are formed. The structures are known to reflect food quality, such as degree of decomposition. Individual expert evaluators have suggested that crystallization images of samples from organic production contain fewer signs of decomposition and that this feature can distinguish organic foods from their conventional counterparts. To further assess the scientific merits of this methodology, a panel of nine evaluators was trained in the visual assessment of biocrystallization images and asked to rank the visual Gestalt decomposition level of encoded images of wheat extracts from i) the same production system at five different decomposition stages and ii) organic production systems vs. conventional production systems aged for the same amount of time. The panel was trained by supervised classification on the basis of defined criteria and intra- and inter-personal variation was assessed. Statistical evaluation showed that the panel was highly reliable, and that the method was appropriate for ranking biocrystallization images of five different decomposition levels. Furthermore, images of samples from organic or conventional production systems could be distinguished with high agreement according to their Gestalt decomposition level with fewer signs of decomposition in the images of organic samples. The rank order between the organic systems vs. the conventional systems was significant.

Development of a sp2-sp3 Stille Cross-Coupling for Rapid Synthesis of HIV NNRTI Doravirine Analogues.

The development of a C(sp2)-C(sp3) cross-coupling reaction for rapid, parallel synthesis of analogues of two HIV NNRTI clinical candidates is described. This method allowed easy access to the C-ring space using a practical alkylation with commercially available tributyl(iodomethyl)stannane followed by a palladium-catalyzed coupling with a variety of aryl halides (I, Br) in the presence of copper chloride. Optimization and scope of this method are reported.

Phosphorus removal from aqueous solution by nanoscale zero valent iron in the presence of copper chloride

This study investigates the adsorption of phosphorus by nanoscale zero valent iron (NZVI) in the presence of copper chloride. The NZVI used for the experiments was synthesized under optimum conditions using the chemical reduction method. The NZVI was characterized by transmission electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller surface characterization and particle size analysis. Batch experiments were performed under different conditions to study the effect of parameters such as initial phosphorus concentration, copper chloride load, aerobic, anaerobic, pH and recovery. The results indicated that the presence of copper chloride effectively enhanced the adsorption capacity of phosphorus as it produced copper ferrite spinel on NZVI particles’ surface which can adsorb phosphorus and increase its rate of adsorption, and also it stimulated NZVI corrosion. The adsorption capacity of phosphorus reached 50mg PO43−-P/g NZVI in the presence of copper chloride while NZVI without copper chloride reached the maximum adsorption capacity of 28mg PO43−-P/g NZVI. Phosphorus recovery batch experiments results showed that the maximum phosphorus recovery achieved at pH 12 was 60%. But the recovery of phosphorus increased by increasing the molarity of the alkaline medium (NaOH) solution used for recovery. A complete recovery of phosphorus was gained using 1M NaOH solution.

Insertion of phosphinidene complexes into the P-H bond of secondary phosphine oxides: a new version of the phospha-Wittig synthesis of P=C double bonds.

Terminal phosphinidene complexes [RP-W(CO)5], as generated at 60 °C in the presence of copper chloride from the appropriate 7-phosphanorbornadiene complexes, react with secondary phosphine oxides Ar2P(O)H to give the insertion products into the P-H bonds. After metalation with NaH, these products react with aldehydes to give the corresponding phosphaalkenes which are trapped by dimethylbutadiene.

ChemInform Abstract: Nanocrystalline Magnesium Oxide‐Stabilized Palladium(0): An Efficient and Reusable Catalyst for Synthesis of N‐(2‐Pyridyl)indoles.

AbstractA heterogeneous catalyst system of magnesia supported palladium nanoparticles furnishes N‐pyridylindoles in the presence of copper chloride as an oxidant.

ChemInform Abstract: Copper Chloride‐Catalyzed Efficient Three‐Component One‐Pot Synthesis of Carbamatoalkyl Naphthols under Solvent‐Free Conditions.

A highly efficient synthesis of carbamatoalkyl naphthols by a one-pot three-component condensation of 2-naphthol, aldehydes, and methyl/ethyl/benzyl carbamates in the presence of copper chloride under thermal solvent-free conditions has been performed. The suitable solvent, amounts of raw materials and catalyst, and reaction temperature were investigated. Experimental results show that only 1 mol% catalyst was enough to induce the conversion. All new products were characterized by mp, IR, 1 H NMR, 13 C NMR and mass spectrum. A mechanism to rationalize the reaction was proposed.

Effects of cementation factors on the Cu nanoparticle deposit of Cu-multi-wall carbon nanotubes composites.

Copper (Cu) coated carbon nanotubes (CNTs) were prepared and investigated by chemical reduction or cementation method. The morphology changes of Cu nanoparticles deposited onto the multiwall carbon nanotubes with metallic zinc (Zn) as a reducing agent have been examined at different cementation factors. The precipitated Cu nanoparticles from the copper ion in the reaction solution were deposited onto and entangled with the CNT substrates. CNTs used were multi-wall carbon nanotubes with average diameter of 10-20 nm and length of 10-50 μm. As-prepared CNTs products were purified by nitric acid solution, and then the CNTs were washed several times with distilled water, and dried in vacuum. The pre-treated CNTs were suspended in solvent. Then, the copper salt was dissolved in the suspension containing the CNTs. The deposited morphology and distribution of copper particles on the CNTs substrate were investigated by changing the solute, solvent and reducing agent. The Cu/CNTs agglomerates were obtained in the presence of copper chloride and copper sulphate salts, and water and ethanol were used as the solvents. And the raw CNTs were pretreated with glacial acetic acid for increasing the coverage rate of copper particles over the CNTs surface at different acid concentrations. The Cu deposited CNTs were characterized in respect of morphology and distribution of CNTs and Cu particles with field emission scanning electron microscopy (FESEM). The copper crystals were identified by X-ray diffraction patterns.

Novel Hyperbranched Molecules Containing Pyrrole Units from Diacetylene Compounds and their Electronic Properties

ABSTRACTNovel hyperbranched molecules containing pyrrole units were obtained from ortho-, meta- and para-diaminodiphenyldiacetylenes, as AB2 type monomers by one-step polymerization. Diacetylenic fragments reacted with terminal amino groups in the presence of copper chloride to give pyrrole units. Diaminodiphenyldiacetylene monomers have been synthesized from ethynilanilines in three steps. The novel monomers and hyperbranched molecules were characterized by NMR, IR and thermal analysis. Some conductivity proofs were also carried out and this behavior was assessed.The electronic behavior of some of these molecules was studied by means of theoretical methods. DFT optimization processes were carried out for three structures derived from the generation growing. There are at least two conformational isomers of the structure (meta- and para-) which show conductivity properties, the meta-isomer shows semiconductor nature but this species is hard to modeling because the steric hindrances cause optimization problems and indeed the third generation species was not achieved. In other context, the para-isomer allows the calculation of three generations and shows clearly a tendency to narrow the energy gap between the frontier orbitals but besides the behavior of the HOMO-1 seems reinforce the conductivity phenomenon.

Simple Access to Tungsten-Stabilized Disecondary Diphosphines

Transient terminal phosphinidene complexes [RP-W(CO)5] dimerize in the presence of copper chloride, and the dimers react in situ with triphenylphosphine–borane to give the disecondary diphosphine complexes [RPH–PHR][W(CO)5]2. When R = CH2CH2Cl, a cyclization takes place to give the diphosphirane complex. A 1,2-diphospholane is obtained for R = Ph by further reaction with 1,3-dibromopropane in the presence of aqueous K2CO3.

ESI–MS study of copper chloride/phase-transfer catalytic systems for oxidation of cumene with 1-methyl-1-phenylethyl hydroperoxide

Oxidation of cumene with 1-methyl-1-phenyl- ethyl hydroperoxide in the presence of copper chloride/ phase transfer catalytic systems was investigated by ESI- MS. For catalytically active copper(II) chloride/crown ethers, copper(II) chloride/crown ethers/alkaline metal salts, and copper(II) chloride/tetrabutylammonium chloride systems, the presence of a few kinds of copper complexes in the organic phase was detected by use of ESI-MS. When copper(II) chloride/podand systems were used, the con- version of hydroperoxide and the yield of oxidation product were close to zero, although the concentration of copper complexes in the organic phase was high. Addition of bis(2-hydroxyethyl) ether to the catalytically active copper(II) chloride/18-crown-6 system resulted in an inhibition effect.

Novel hyperbranched molecules containing pyrrole units from diacetylene compounds

Novel hyperbranched molecules containing pyrrole units were obtained from ortho-, meta-, and para-diaminodiphenyldiacetylenes, as AB2 type monomers by one-step polymerization. Diacetylenic fragments reacted with terminal amino groups in the presence of copper chloride to give pyrrole units. Diaminodiphenyldiacetylene monomers have been synthesized from ethynilanilines in three steps. The novel monomers and hyperbranched molecules were characterized by NMR, IR and thermal analysis.

Identification of Iodine-Induced Morphological Transformation of Gold Nanorods

The morphological transformation process resulting from the reaction between Au nanorods (NRs) and iodine in situ produced from the redox between potassium iodide and copper chloride was monitored by virtue of the transmission electron microscope (TEM) images and the plasmon resonance absorption (PRA) spectra. It was found that the presence of copper chloride or potassium iodide could make the longitudinal PRA band of Au-NRs shift without any change of morphological transformation owing to the change of the refractive index of the medium. Different from that, iodine, which was in situ produced from the redox of potassium iodide and copper chloride, could fuse Au-NRs in the side-by-side mode, resulting in morphological transformation of Au-NRs to sphericity with the characteristics of the decrease of aspect ratio, blue-shift of the longitudinal PAR band, red-shift of transverse PRA band, and broadening of both longitudinal and transverse PRA bands of Au-NRs. The blue-shifted wavelength of the longitudinal ...