Presence Of CuCl Research Articles

ChemInform Abstract: Synthesis and Reactivity of Oxygen Chelated Ruthenium Carbene Metathesis Catalysts.

AbstractSix NHC Ru complexes are prepared by etherification of 4‐substituted 2‐(propen‐1‐yl)phenols with either ethyl alpha‐bromopropionate or 2‐bromo‐gamma‐butyrolactone followed by reaction with Grubbs 2nd generation catalyst in the presence of CuCl.

ChemInform Abstract: Copper‐Catalyzed Chan—Lam Coupling Between Sulfonyl Azides and Boronic Acids at Room Temperature.

AbstractAn efficient coupling of a variety of sulfonyl azides with arylboronic acids proceeds in the presence of CuCl as catalyst and gives generally good yields of the corresponding N‐aryl sulfonamides.

ChemInform Abstract: CuCl‐Catalyzed Ring‐Opening Isomerization of gem‐Chlorofluorocyclopropanes with the Formation of Chlorofluoroalkenes and Chlorofluoroalkadienes.

AbstractTitle reactions are easily effected in the presence of CuCl with phenyl‐, alkyl‐, vinyl‐, and cyclopropyl‐substituted cyclopropanes.

Nitrone‐Mediated Radical Coupling of Polymers Derived from Reverse Iodine‐Transfer Polymerization

The current study describes the synthesis of iodine‐end‐capped polystyrene (PS) and poly(methyl methacrylate) (PMMA) precursors using reverse iodine‐transfer polymerization, which, in a second step, are used in nitrone‐mediated radical coupling (NMRC) reactions. Initially, the reverse iodine polymerization of both monomers is studied and optimized in order to obtain iodine‐end‐capped materials with controlled molecular weights and low dispersities. Subsequently, NMRC of both PS and PMMA precursors is carried out in the presence of CuCl as a halide‐exchange agent. Coupling efficiencies of xc = 0.754 for PS‐I and 0.84 for PMMA‐I are observed; however, the addition of 10 equivalents of styrene is required to promote the coupling in the case of methacrylate. The presence of the desired alkoxyamine functionality in mid‐chain position of the products is evidenced via quenching experiments. image

Effects of some Abiotic Factors on Brassica Oleracea Var. Capitata Sprouts

Nowadays there is a continuous increase of sprouts consumption. The white cabbage is known as a resistant plant at different abiotic factors. It has the capacity to accumulate heavy metals without visible phytotoxicity symptoms, when the concentration is not excessively high. The morphological and biochemical modifications induced in cabbage sprouts by two heavy metals (Cu and Mn) were analysed comparing with the effects of salt stress. The metal accumulation in sprouts was measured, because over a certain level, it may become dangerous for the consumers health. The sprouts were grown in a germinator in specific conditions for 10 days, in the presence of CuCl2, MnCl2, NaCl or water respectively. For each treatment, we used three concentrations. It was analyzed the accumulation of each metal in the cabbage sprouts (by AAS method), the influence of each metal concentration on the seeds germination and on the sprouts growth (by biological determination) and photosynthetic pigments concentration (by spectrophotometric method). The treatment with Mn and Na at the studied concentrations is not inhibiting the sprouts growth (only Cu does) and is not inducing phytotoxicity symptoms (contrary, is stimulating the growth in some cases). The accumulation of the heavy metals in sprouts is significant and may become dangerous for the consumer health, if the quantity of the ingested sprouts is important.

Synthesis and Characterization of 3-Chloropropyl-substituted o- Carboranes: Crystal Structures of 1,2-(1,3-Propanediyl)-o-carborane, 1-(3-Chloropropyl)-o-carborane and 1,2-Bis(3-chloropropyl)-ocarborane

The reactions of the lithio-o-carborane Li2C2B10H10 with ClCH2CH2CH2Br were studied under various conditions. While the main product is the known exo-polyhedrally cyclized 1,2- (1,3-propanediyl)-o-carborane (2), the expected 3-chloropropyl-substituted carborane products 1- (ClCH2CH2CH2)C2B10H11 (3) and 1,2-(ClCH2CH2CH2)2C2B10H10 (4) can be obtained in a total yield of 22%. In the presence of CuCl, the same reaction proceeded rather slowly and gave compound 3and bis(o-carborane) (5) in small yields, with the recovery of the starting o-C2B10H12. Compounds 2- 4were characterized by means of IR and NMR spectroscopy and mass spectrometry, as well as by single-crystal X-ray diffraction.

Synthesis and reactions of trinitro-9,10-phenanthrenequinone derivatives

The reaction of 2,4,7-trinitro-9,10-phenanthrenequinone with CuCl in aqueous dimethylformamide or dimethyl sulfoxide at room temperature, followed by acidification, gave a stable red complex of 2,4,7-trinitro-9,10-dihydroxyphenanthrene with a solvent molecule. On heating in a polar aprotic solvent in the presence of CuCl or other metal salt, 2,4,7-trinitro-9,10-phenanthrenequinone underwent benzilic acid rearrangement with formation of 2,4,7-trinitrofluorenone. The nitration of 9,10-sulfuryldioxyphenanthrene and subsequent decomposition of cyclic sulfates afforded previously unknown 1,3,6-trinitro- and 1,8-dinitro-9,10-phenanthrenequinones.

1,2,3,4‐Tetrasubstituted Cyclopentadienes and Their Applications for Metallocenes: Efficient Synthesis through Zirconocene‐ and CuCl‐Mediated Intermolecular Coupling of Two Alkynes and One Diiodomethane

1,2,3,4-Tetrasubstituted cyclopentadienes and indene derivatives with identical or different substituents were obtained in good to excellent isolated yields through a zirconocene- and CuCl-mediated intermolecular coupling process. This synthetic procedure involved three organic partners, including one CH2 I2 , and two different or identical alkynes. Two alkynes or one diyne undergo Cp2Zr(II)-mediated (Cp = η(5)-C5H5) pair-selective reductive coupling to afford the corresponding zirconacyclopentadiene derivatives, which react, in the presence of CuCl and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1 H)-pyrimidinone (DMPU), with CH2I2 through intermolecular followed by intramolecular coupling to afford the cyclopentadiene derivatives. An application of the prepared tetrasubstituted cyclopentadiene derivatives was demonstrated by the facile synthesis of the corresponding zirconocene complexes [((4R)Cp)2ZrCl2] and [((4R)Cp)2ZrR'2] (R' = Me, Et, or nBu). The unique 1,2,3,4-tetrasubstituted cyclopentadiene ligands and the corresponding metallocenes are expected to have further applications in organometallic chemistry and organic synthesis.

Synthesis of Isocoumarin Derivatives by Copper-Catalyzed Addition of o-Halobenzoic Acids to Active Internal Alkynes

The addition of o-halobenzoic acids to active internal alkynes proceeds efficiently in the presence of CuCl(2) as a catalyst to give the corresponding isocoumarin derivatives in moderate to good yields. This strategy offers a simple, efficient route to synthesis of the isocoumarin derivatives.

The fabrication of controlled coral-like Cu2O films and their hydrophobic property

In this paper, we report on the nanostructured Cu2O film with controllable coral-like morphology in the presence of CuCl2 by electrodeposition without using any performed template. Four types of patterned Cu2O films including grains-like, agaric-like, frutex-like and coral-like films were achieved by governing the time or additive. The coral patterned Cu2O film is for the first time found here. Additionally, possible growth mechanism for multi-patterned Cu2O is discussed via preferential growths induced by selective absorption of Cl− ions in the present reaction system. The resulting pattered films displayed tunable hydrophobic and even superhydrophobic properties owing to their special surface with micro-/nanostructures after simple surface modification. These experimental results prove a versatile and facile strategy for Cu2O films with special and complex architectures which may highlights their potential applications in self-cleaning equipment due to the improved surface activity.

Pd-Catalyzed β-Selective Direct C–H Bond Arylation of Thiophenes with Aryltrimethylsilanes

Direct arylation of thiophenes and benzothiophenes with aryltrimethylsilanes was effectively catalyzed by PdCl(2)(MeCN)(2) in the presence of CuCl(2) as an oxidant. The reaction preferentially occurred at the β-position of both thiophenes and benzothiophenes.

A Mild and Practical Synthesis of Biphenyl Compounds

A mild and practical synthetic route for biphenyls is established. Isopropyl nitrite was prepared from sodium nitrite, isopropanol and hydrochloric acid. The biphenyl compounds were obtained from the diazotisation of aniline derivatives with the generated isopropyl nitrite and the coupling reaction with benzene derivatives in the presence of CuCl as a catalyst in good yields.

N-(1-Azanidyl-2,2,2-trichloroethylidene)-2,2,2-trichloroethanimidamide]copper(II)

The title compound, [Cu(C4H2Cl6N3)2], was obtained by the reaction of CCl3CN with ammonia in presence of CuCl. The CuII atom is located about an inversion centre. The mol­ecule consists of three planar units (one central square CuN4 and two C2N3 fragments), adopting a staircase-like structure. The six-membered metallocycles have a sofa conformation with the Cu atom out of the plane of the 1,3,5-triaza­penta­dienyl ligands by 0.246 (5) Å. The ipso-C atoms of the CCl3 substituents are slightly out of the 1,3,5-triaza­penta­dienyl planes by 0.149 (6) and −0.106 (6) Å. The CCl3 groups of each 1,3,5-triaza­penta­dienyl ligand are practically in the energetic­ally favourable mutually eclipsed conformation. In the crystal, the mol­ecules are packed in stacks along the a axis. The mol­ecules in the stacks are held together by two additional axial Cu⋯Cl inter­actions of 3.354 (2) Å. Taking the axial Cu⋯Cl inter­actions into account, the CuII atom exhibits a distorted [4 + 2]-octa­hedral coordination environment. The stacks are bound to each other by weak inter­molecular attractive Cl⋯Cl [3.505 (2)–3.592 (3) Å] inter­actions.

ChemInform Abstract: Asymmetric α‐Hydroxy Ketone Synthesis by Direct Ketone Oxidation Using a Bimetallic Palladium(II) Complex.

Abstract The oxidation of ketones by a chiral bimetallic palladium(II) complex in the presence of CuCl 2 in THF–water solvents gave an enantioselective synthesis of α-hydroxyketones in catalytic oxidation utilizing an atmosphere of oxygen. The ee’s ranged from 61% to 92%. The reaction was accelerated by addition of strong acid that presumably increases the rate of enolization.

Pentafluorophenylammonium triflate-CuCl2: A mild, efficient and reusable heterogeneous catalyst system for facile synthesis of 4(3H)-quinazolinones under solvent-free conditions

Pentafluorophenylammonium triflate (PFPAT) was found to be highly efficient, and recyclable heterogeneous catalyst for the synthesis of 4(3H)-quinazolinones by cyclocondensation reaction of 2-aminobenzamide with aryl aldehydes in the presence of CuCl2 as co-catalyst in good to excellent yields under solvent-free conditions. The present methodology offers several advantages, such as simple procedure with an easy work-up, high yields, short reaction times, and the absence of any volatile or hazardous organic solvents. Moreover, the catalyst can be easily recovered and reused at least three times with only slight reduction in its catalytic activity.

Copper(I)-Catalysed Deacetylenative Cross-Coupling Reaction of Terminal Alkynes with Propargylic Amines via C(sp)-C(sp3) Bond Cleavage

The catalytic deacetylenative coupling reaction of terminal alkynes with various N-substituted propargylic amines proceeded in the presence of CuCl (10 mol%) and Na 2 HPO 4 (4 equiv) in THF at 130 °C to give the corresponding substituted propargylic amines in good to high yields.

Asymmetric α-hydroxy ketone synthesis by direct ketone oxidation using a bimetallic palladium(II) complex

The oxidation of ketones by a chiral bimetallic palladium(II) complex in the presence of CuCl2 in THF–water solvents gave an enantioselective synthesis of α-hydroxyketones in catalytic oxidation utilizing an atmosphere of oxygen. The ee’s ranged from 61% to 92%. The reaction was accelerated by addition of strong acid that presumably increases the rate of enolization.

Ammonia borane thermolytic decomposition in the presence of metal (II) chlorides

In the present work, we studied the effect of metal chlorides, MCl2, on the thermal decomposition of ammonia borane NH3BH3 (AB). Some metals from row n=4 of the periodic table were chosen and used as MCl2: namely, FeCl2, CoCl2, NiCl2, CuCl2, and ZnCl2. In addition, three metals from column VIII of the periodic table were considered: NiCl2, PdCl2 and PtCl2. The AB decomposition was followed by TGA and DSC; the decomposition gases analyzed by μGC/MSD coupling, and the solid by-products identified by XRD, IR and XPS. We observed that the presence of CuCl2 in AB is beneficial, making the decomposition occur in much milder conditions than for pristine AB; for example, the dehydrogenation of CuCl2-doped AB started at 25°C, with the sample losing about 14 wt% at 85°C. However, MCl2 does not hinder the evolution of the undesired borazine; it only contributes to a decrease in its content compared to pristine AB. To rationalize the better performance of CuCl2, we propose that Cu offers an optimal doping activity with intermediate binding energies for the intermediates: i.e. with H not too strongly bonded but optimally bonded to the N of AB. The germ Cu⋯NH2–BH2, then formed, acts as a Lewis acid through B and has an optimized reactivity towards a new AB molecule (head-to-tail dehydrocoupling). This is discussed herein.

Copper-mediated synthesis of N-fused heterocycles via Csp–S coupling reaction and 5-endo-dig cyclization sequence

A novel method was developed for the preparation of N-fused heterocycles via a Csp–S coupling reaction and a sequence of 5-endo-dig cyclization. This method involves the reaction of –NHC(S)NH-containing compounds and alkynes in the presence of CuCl and N,N′-dicyclohexylimidazolium chloride.

Mechanochemistry: A review of surface reactions and environmental applications

Mechanochemistry is the study of physico-chemical transformations generated by mechanical force. This force may break down crystals, thus exposing fresh, active surfaces and enhance the mass transfer required for reaction partners in the solid state to make the contact required for initiating a chemical reaction. Application of mechanical force may facilitate sorption-induced steric enhancement of transformations catalyzed by ions of transition metals (e.g., cations of such metals serving as counter ions in exchange complexes of clays). The formation of mixed Cu–Na–montmorillonite from Na–montmorillonite ground with CuCl2 in the presence of imazaquin and the resultant breakdown of imazaquin is one example of this phenomenon. Reported mechanochemical reactions which involve minerals, include redox reactions, polymerization and polymer rearrangements, recrystallization and dehydration. The more widespread methods for removing organic contaminants from soils are based on biological degradation. Biological processes, however, have certain shortcomings such as the substantial time they require, or the significant concentrations of harmful residues that are left in the soil. Alternative soil remediation schemes are, therefore, needed and mechanochemical procedures may be part of such innovative cleanup protocols. Mechanochemistry can be applied at the field scale and mechanochemical techniques were already suggested as a clean and cheap approach to hazardous waste management and destruction. Furthermore, soil tillage is actually a process in which mechanical force is applied to the soil and hence, it may induce a variety of mechanochemical reactions.Clays and metal (especially iron and manganese) oxides catalyze numerous transformations of organic compounds when such compounds are sorbed on the minerals' surfaces. The catalytic efficiency of these minerals is, at least in part, due to their strong acidity, both Bronsted and Lewis, and to the large specific surface area they may possess. Manganese and iron are redox active and their minerals are thus capable of supporting both electron and proton transfer reactions. Since iron oxides are abundant in soils, transformations augmented by these minerals are of considerable environmental importance. In the present review, case studies of mechanochemically induced transformations of pollutants are presented. The breakdown of pesticides (2,4-D, imazaquin and atrazine) and of other organic pollutants such as DCP and PAHs achieved by light grinding for short durations (a few minutes) in a mixture with minerals which are soil components or the derivatives of such components is described. Among the tested minerals, Al– and Cu–montmorillonite, iron oxides and Mn oxides were the most effective heterogeneous catalysts. The effectiveness of the minerals depended strongly on the degraded pollutant and on the conditions (e.g., the moisture content) under which the mechanochemical reaction took place. Although the presence of water often hinders the degradation, in some cases the reverse is true. Na–montmorillonite in the presence of CuCl2 was effective in degrading imazaquin when the mixture was ground wet. This demonstrates a detoxification process applicable to real-world systems which are often wet.