Presence Of CuCl Research Articles

Study of the Effect of Zn, Sn, and Pb Additives on the Direct Mechanochemical Synthesis of Tetramethoxysilane in the Presence of CuCl and CuO Catalysts

Study of the Effect of Zn, Sn, and Pb Additives on the Direct Mechanochemical Synthesis of Tetramethoxysilane in the Presence of CuCl and CuO Catalysts

Copper‐Catalyzed Stepwise Aerobic Oxidation/N‐Arylation from Benzothiazole

AbstractWe report herein an efficient synthesis of 3‐arylbenzothiazolin‐2‐one compounds. First, substituted benzothiazoles can be smoothly oxidized to benzothiazolin‐2‐one derivatives in the presence of CuCl2 and trifluoroacetic anhydride. Secondly, the Cu2S‐catalyzed N‐arylation of benzothiazolin‐2‐one with arylboronic acids yields a series of novel 3‐aryl benzothiazolin‐2‐one derivatives. The method provides good yields for a variety of substrates and shows good compatibility with functional groups. The usefulness of the skeleton was further illustrated by the derivatization of 3‐aryl‐benzothiazolin‐2‐one. Mechanistic studies suggest that the oxidation of benzothiazole may undergo a free radical reaction process.

Copper‐Enabled Photo‐Sulfonylation of Aryl Halides Using Alkylsulfinates

AbstractA photochemical synthetic method to access sulfones from aryl halides and sodium alkylsulfinates in the presence of CuCl is reported. Regio‐ and chemoselectivity for the sulfonylation is observed for polyhalogenated arenes. Mechanistic studies indicate that a copper sulfinate reagent is formed in situ from CuCl and sodium sulfinate based on NMR experiments. Potential reaction intermediates, including excited state aryl halides are studied using density functional theory calculations and reveal energetically accessible non‐planar triplet geometries.

Synthesis and Characterization of Some New Uracil Derivatives and their Biological Activity

This research includes the synthesis of thirty derivatives of uracil. 
 Nucleophilic substitution reaction (thiol, alkylthio, hydrazino, 
 thioacid,.. etc) of 4-chlorouracil afforded the corresponding 
 derivatives. The 4-(2`-thiol-1` ,3`,4`-oxadiazole-5`-thiomethyl) uracil 
 (12), ( N` - phenyl – 2` - thio -1` ,3`,4`-triazole-5`-methyl)-(2,6-
 dihydroxy-4-pyrimidinyl) sulphide (14) and 5-(2`,6`-dihydroxy-4`-
 pyrimidinyl thioacetamido)-1,3,4-thiadiazole-2-thiol (15), were 
 synthesized by treatment of 4-thioacetichydrazide uracil (11) with 
 carbon disulfide in the presence of a base or phenylisothiocyanate in 
 the presence of base. Mannich bases of alkynyl thio derivativeis (3a & 
 10) were synthesized by the reaction of paraformaldehyde and 
 secondary amine in the presence of CuCl (19a,b & 20a,b). 
 These compounds were characterized by spectroscopic methods (IR & 
 UV), by their elemental analysis (C,H,N) and Rf values. 
 Biological activity of the synthesized compounds was determined

Cations Modulated Assembly of Triol-Ligand Modified Cu-Centered Anderson-Evans Polyanions.

Counter-cations are essential components of polyoxometalates (POMs), which have a distinct influence on the solubility, stabilization, self-assembly, and functionality of POMs. To investigate the roles of cations in the packing of POMs, as a systematic investigation, herein, a series of triol-ligand covalently modified Cu-centered Anderson-Evans POMs with different counter ions were prepared in an aqueous solution and characterized by various techniques including single-crystal X-ray diffraction. Using the strategy of controlling Mo sources, in the presence of triol ligand, NH4+, Cu2+ and Na+ were introduced successfully into POMs. When (NH4)6Mo7O24 was selected, the counter cations of the produced POMs were ammonium ions, which resulted in the existence of clusters in the discrete state. Additionally, with the modulation of the pH of the solutions, the modified sites of triol ligands on the cluster can be controlled to form δ- or χ-isomers. By applying MoO3 in the same reaction, Cu2+ ions served as linkers to connect triol-ligand modified polyanions into chains. When Na4Mo8O26 was employed as the Mo source to react with triol ligands in the presence of CuCl2, two 2-D networks were obtained with {Na4(H2O)14} or {{Na2(H2O)4} sub-clusters as linkers, where the building blocks were δ/δ- and χ/χ-isomers, respectively. The present investigation reveals that the charges, sizes and coordination manners of the counter cations have an obvious influence on the assembled structure of polyanions.

Producing Methyl p-Coumarate from Herbaceous Lignin via a "Clip-Off" Strategy.

As the most abundant renewable aromatic resource on Earth, lignin is a preferred starting material for producing bulk chemicals via a sustainable route. In this study, we provide a novel and efficient "clip-off" approach for producing methyl p-coumarate, an important and versatile fine chemical by selective cleavage of the ester linkage in herbaceous lignin in the presence of commercial metal chlorides. When bagasse lignin was depolymerized at 155 °C for 4 h, a 12.7% yield of aromatic chemicals was obtained in the presence of CuCl2, 71.7% of which was identified as methyl p-coumarate (the yield was 9.1%). Further investigation of the structural evolution of lignin revealed that the ester linkages in lignin were efficiently broken via intensive transesterification with methanol accompanied by the simultaneous weakening of the inter-/intramolecular hydrogen bonds. Moreover, this observation of selective cleavage of ester linkages could be further confirmed by the conversion of model compounds with characteristic bonds under identical reaction conditions. Therefore, this work provides a new insight into the production of value-added chemicals from renewable resources.

Pd-Catalyzed desulfitative arylation of olefins by N-methoxysulfonamide.

A novel Pd-catalyzed protocol for the desulfitative Heck-type reaction of N-methoxy aryl sulfonamides with alkenes was reported. The cross-coupling reaction was performed successfully with a variety of olefins to obtain aryl alkenes. Different substituents on the aromatic ring of N-methoxysulfonamides were also found to be compatible with the reaction conditions. Expectedly, the reaction proceeds through CuCl2-promoted generation of the nitrogen radical and subsequent desulfonylation under thermal conditions to afford the aryl radical for the Pd-catalyzed coupling reaction. N-Methoxysulfonamide was further exploited for the synthesis of symmetrical biaryls in the presence of CuCl2.

CuCl2·2H2O/TBHP mediated synthesis of β-enaminones via coupling reaction of vinyl azides with aldehydes.

A facile and efficient oxidative functionalization of vinyl azides with aldehydes furnishing a diverse array of β-acylated enaminones was developed. The cross coupling was accomplished in the presence of CuCl2·2H2O/TBHP and produced the desired β-acylated enaminones in a (Z)-stereo-selective and atom-economic manner, which make this protocol particularly attractive. In the transformation, the new C-C and C-N bonds were formed via a one-pot strategy including the process of radical addition and recombination.

A mixed-valence CuII/CuI coordination polymer based on bridged thiocyanate and in situ formed di(N-heterocyclic) sulfide: Synthesis, structure, and magnetic properties

A mixed-valence CuII/CuI coordination polymer {CuIICuI2[S(PIP)2](μ-SCN)4}n (1) has been generated via the reaction of KSCN, CuCl2·2H2O, and 3-(pyridin-2-yl)imidazo[1,5-a]pyridine (HPIP) under solvothermal conditions. The di(N-heterocyclic) sulfide ligand [S(PIP)2] (S(PIP)2 = bis(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl)sulfane) was formed in situ by the reaction of HPIP and KSCN in the presence of CuCl2·2H2O. The structure of compound 1 was determined by X-ray single crystal diffraction. In the structure of 1, one CuII ion, which is chelated by one neutral [S(PIP)2] ligand, and two CuI ions are connected by end-to-end thiocyanates to generate an infinite 2D coordination polymer. Complex 1 was also characterized by IR, PXRD, XPS and ESR. The magnetic properties of 1 have been investigated.

Synthesis of (+)-Muconin via Diastereoselective Oxypalladation.

Synthesis of (+)-muconin isolated from Rollinia mucosa (Annonaceae) was achieved. Stereoselective construction of a tetrahydrofuran-terahydropyran (THF-THP) ring moiety was performed using diastereoselective oxypalladation in the presence of CuCl2. The cross-coupling reaction of the THF-THP moiety with the γ-lactone portion followed by reduction of the enyne and removal of the protecting groups afforded (+)-muconin.

Spermatozoa Transcriptional Response and Alterations in PL Proteins Properties after Exposure of Mytilus galloprovincialis to Mercury.

Mercury (Hg) is an environmental pollutant that impacts human and ecosystem health. In our previous works, we reported alterations in the properties of Mytilus galloprovincialis protamine-like (PL) proteins after 24 h of exposure to subtoxic doses of toxic metals such as copper and cadmium. The present work aims to assess the effects of 24 h of exposure to 1, 10, and 100 pM HgCl2 on spermatozoa and PL proteins of Mytilus galloprovincialis. Inductively coupled plasma–mass spectrometry indicated accumulation of this metal in the gonads of exposed mussels. Further, RT-qPCR analyses showed altered expression levels of spermatozoa mt10 and hsp70 genes. In Mytilus galloprovincialis, PL proteins represent the major basic component of sperm chromatin. These proteins, following exposure of mussels to HgCl2, appeared, by SDS-PAGE, partly as aggregates and showed a decreased DNA-binding capacity that rendered them unable to prevent DNA damage, in the presence of CuCl2 and H2O2. These results demonstrate that even these doses of HgCl2 exposure could affect the properties of PL proteins and result in adverse effects on the reproductive system of this organism. These analyses could be useful in developing rapid and efficient chromatin-based genotoxicity assays for pollution biomonitoring programs.

Selective Synthesis of Pyrano[3,2-b]indoles or Cyclopenta[b]indoles Tethered with Medium-Sized Rings via Cascade C-C σ-Bond Cleavage and C-H Functionalization.

Highly atom-economical tandem reactions have been developed for the synthesis of pyrano[3,2-b]indoles or cyclopenta[b]indoles tethered with 7-, 8-, or 9-membered rings. These reactions first undergo a carbon-carbon σ-bond cleavage reaction of cyclic β-ketoesters. Next, in the presence of CuCl2 and Ag2CO3, intramolecular O-H/C-H coupling occurs to give pyrano[3,2-b]indoles. This is the first example for capture of the enoloxyl radical of the intramolecular C-O bond formation reaction, whereas C3 nucleophilic addition afforded cyclopenta[b]indoles using TsOH·H2O.

Molecular Alterations in Spermatozoa of a Family Case Living in the Land of Fires—A First Look at Possible Transgenerational Effects of Pollutants

In our previous work, we reported alterations in protamines/histones ratio, in DNA binding of these proteins and their involvement in DNA oxidative damage in 84% of the young men living in the Land of Fires. In the present work, we extended our findings, evaluating any alterations in spermatozoa of a family case, a father and son, living in this area, to also give a first look at the possibility of transgenerational inherited effects of environmental contaminants on the molecular alterations of sperm nuclear basic proteins (SNBP), DNA and semen parameters. In the father and son, we found a diverse excess of copper and chromium in the semen, different alterations in SNBP content and low DNA binding affinity of these proteins. In addition, DNA damage, in the presence of CuCl2 and H2O2, increased by adding both the father and son SNBP. Interestingly, son SNBP, unlike his father, showed an unstable DNA binding and were able to produce DNA damage even without external addition of CuCl2, in line with a lower seminal antioxidant activity than the father. The peculiarity of some characteristics of son semen could be a basis for possible future studies on transgenerational effects of pollutants on fertility.

Petroleum Coke Combustion in Fixed Fluidized Bed Mode in the Presence of Metal Catalysts.

Petroleum coke is one of the waste products generated in the oil refining industry that can be used as fuel in energetics. However, the low volatile matter content and graphite-like structure of petroleum coke are the reasons for its high ignition temperature and combustion complexity. In this research, petroleum coke combustion and oxidation kinetics in the presence of metal catalysts were investigated. To evaluate the effect of the catalyst on the ignition temperature and the apparent activation energy, a new approach of a “fixed fluidized bed” was proposed. In this mode, petroleum coke particles spaced from each other by inert quartz powder kind of “freeze” in the porous layer. This regime allows us to determine the ignition temperature of petroleum coke particles in the static mode by differential thermography and calculate the activation energy by gas analysis. Organic and inorganic salts of copper, iron, and cerium are used as catalysts for petroleum coke combustion. A series of experiments were carried out in the porous media thermo-effect cell (PMTEC) and on a thermogravimetric (TG) analyzer. The kinetics of the combustion processes was calculated by Kissinger–Akahira–Sunose and Ozawa–Flynn–Wall methods. The results obtained in the “fixed bed” mode showed that the ignition temperature and the average apparent activation energy significantly decreased in the presence of CuCl2 and FeCl3. The results obtained by the new approach were compared with the results of the thermogravimetric analysis.

Copper-Mediated Cascade Synthesis of Open-Cage Fullerenes

An open-cage fullerene bearing an eight-membered ring orifice has been synthesized in one pot by the reaction of C60 with propargylic phosphate in the presence of CuCl. The reaction cascade involves the transformation of the phosphate to the 1,3-dienyl phosphate, which enables the reaction with C60 by [4 + 2] cycloaddition to form the cyclohexene-annulated intermediate, and subsequent intramolecular syn-elimination of the phosphodiester affords the cyclohexadiene-annulated fullerene derivative as the precursor for the open-cage fullerene.

Cu(ii) salen and 1,2,4-triazole complexes from thiosemicarbazone: synthesis, physicochemical and structural properties and cytotoxic activities

The complexes were synthesized from reaction of salicylaldehydethiosemicarbazone and ethylenediamine in the presence of CuCl2.

Tetrazole Based Porous Metal Organic Framework (MOF): Topological Analysis and Dye Adsorption Properties

A tetrazole based metal organic framework [Cu(Metet)]n (MOF-1) (MetetH = 5-methyl-1H-tetrazole) has been prepared under solvothermal condition using sodium azide and nitrile in presence of CuCl2·2H2O. The crystalline product thus obtained was characterized by spectral (FTIR, UV–visible and fluorescence) and single crystal X-ray diffraction analysis. Tetrazole ligand is formed in situ by the reaction of azide and nitrile used. X-ray data confirm the tetrahedral geometry around the Cu(II) ion where all the four coordination sites are provided by four N of the four different ligand (Metet). MOF-1 has trigonal crystal system with R-3 m space group. Topological analysis of MOF-1 shows 4,4-c binodal net with uncommon ptr topology and stoichiometry, (4-c)(4-c). The detailed structural analysis reveals the porous nature of the MOF with channel of dimensions, Rf = 0.6 A and Rfi = 2 A. Further, the present MOF shows excellent adsorption properties towards organic dye, Methylene blue (MB) and thus can be employed as a good adsorbent for organic pollutants to remove MB from waste water. The possible rationale behind the dye adsorption is the porous nature of the MOF-1.

Synthesis, crystal structure and biological activity of new phosphoester-p-substituted-methylparabens

Bis(4-(methoxycarbonyl)phenyl)phosphonate and bis(4-(methoxycarbonyl)phenyl) phosphate were prepared from the reaction of p-hydroxybenzoate with phenyl phosphonic dichloride and with phenyl dichlorophosphate, respectively, in the presence of CuCl as catalyst. The structure of the synthesized compounds was elucidated by FTIR, 1H NMR,13C NMR and 31P NMR spectroscopy. The assignments for the 1H, 13C and 31P chemical shifts are based on 1D and 2D NMR homo- and heteronuclear correlations (H,H-COSY (Correlation Spectroscopy), H,C-HMQC (Heteronuclear Multiple Quantum Correlation and H,C-HMBC (Heteronuclear Multiple Bond Correlation)) and 31P-13C couplings. The synthesized compounds revealed good solubility in common organic solvents. The crystal structure of the products was investigated by single-crystal X-ray diffraction, while the purity of the bulk product was confirmed by powder X-ray diffraction. The antimicrobial effect of the non-phosphoester-functionalized and phosphoester-functionalized p-hydroxybenzoate disc samples was investigated. Antimicrobial activities were evaluated against bacterial strains of Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and fungi Candidaalbicans ATCC 10321 used in this research. The non-phosphoester-functionalized p-hydroxybenzoate exhibit good antibacterial and antifungal effect compared to phosphoester-functionalized p-hydroxybenzoates. The synthesized compounds were screened in vitro for their cytotoxicity on primary Albino Rabbit dermal fibroblasts, by the 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) protocol. The results showed clearly that the synthesized phosphoesters promote cell viability and they have the potential to be developed into economical and reliable additives for skin cosmetics and pharmaceuticals.

One pot multicomponent synthesis of Novel Bis‐N‐(1,2,3‐ triazolylacetyl) as Potent Antioxidant and Antibacterial Agents

AbstractA new series of bis‐triazoles has been synthesized through cycloaddition of prepared bis‐azides and diethyl acetylenedicarboxylate in the presence of CuCl2 under solvent‐free condition. Antioxidant activity of products at the concentration of 2000‐62.5 μg/mL using ABTS method was studied and products showed good antioxidant activity. Moreover, IC50 values of products were ranged from 2.00 to 0.06 mM and products 5f‐g and 5i possessed high antioxidant activity and lower IC50 values than ascorbic acid (vitamin C). Also, products 5g and 5e showed the lowest and highest antioxidant activities, respectively. Moreover, in vitro minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) of bis‐triazoles were screened against Gram‐positive bacteria strains including Micrococcus luteus and Staphylococcus Gram‐negative bacteria strains including Escherichia coli and Pseudomonas aeruginosa. Most of the products showed a lower MIC than penicillin against tested bacterial strains and also most of the products were active against negative bacterial strains.

Effects of different metabolic pathways and environmental parameters on Cr isotope fractionation during Cr(VI) reduction by extremely thermophilic bacteria

Abstract Chromium isotopes are promising for monitoring and quantifying the extent of microbial Cr(VI) reduction. However, the mechanisms and factors that influence Cr isotope fractionation are not well understood. In the present study, we investigated the effects of different metabolic pathways and various environmental parameters on Cr isotope fractionation during Cr(VI) reduction by the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus. The Cr isotopic compositions were measured on unreacted Cr(VI) in the remaining solution. The reaction product is isotopically lighter than the reactant. The Cr isotope composition for remaining Cr(VI) in the solution followed a Rayleigh fractionation trend and thus became increasingly isotopically heavier as the reduction of Cr(VI) proceeded. Cr(VI) reduction mainly occurs on the cell surface by Ni–Fe hydrogenase; however, in the presence of CuCl2, the activity of Ni–Fe hydrogenase was inhibited, and Cr(VI) was reduced inside the cells. We found that despite different Cr(VI) reduction locations, Cr isotope enrichment factors (e = (α − 1) × 1000, where α is the fractionation factor) were identical within uncertainty for experiments with and without CuCl2 (−2.72 ± 0.67‰ and −2.92 ± 0.14‰, respectively). When added to the cell cultures, neutral red (NR) functioned as an electron carrier that enabled bacteria to drive the electron transfer processes. The e values were also similar for experiments with and without NR (−2.53 ± 0.40‰ and −2.92 ± 0.14‰, respectively). We compared these e values to investigate the effects of different electron transport pathways and cellular Cr(VI) transfer processes, including Cr(VI) transport across the cell envelope and binding to reacting enzymes, on Cr isotope fractionation. Furthermore, the effects of various environmental parameters on Cr isotope fractionation were tested, including temperature (50 °C and 70 °C), hydrogen concentration, and different electron donors (glucose and hydrogen). The e values were similar at both tested temperatures and stayed within the previously observed range for mesophiles; changes in hydrogen concentration also did not affect the e values. However, the e values were slightly higher with hydrogen as the electron donor (−3.64 ± 0.24‰) than those with glucose as the electron donor (−2.92 ± 0.14‰). In short, the Cr enrichment factors remained unchanged despite of changing microbial Cr (VI) reduction pathways and changing temperature conditions, but may be sensitive to the electron donor type.