Simple Copper Salt Research Articles

Scope and reaction mechanism of an aerobic oxidative alkyne homocoupling catalyzed by a di-copper-substituted silicotungstate

The di-copper-substituted γ-Keggin-type silicotungstate TBA 4[γ-H 2SiW 10O 36Cu 2(μ-1,1-N 3) 2] ( I, TBA = tetra- n-butylammonium) could act as an efficient reusable homogeneous catalyst for the aerobic oxidative alkyne homocoupling. Various kinds of structurally diverse terminal alkynes including aromatic, heteroaromatic, aliphatic, double bond-containing, silylacetylene, propargylic alcohol, and propargylic amine derivatives could selectively be converted into the corresponding diynes in the presence of I. The catalytic activity of I was much higher than those of the mono-copper-substituted silicotungstate, monomeric copper complexes, and simple copper salts, showing that the di-copper core in I plays an important role in the present alkyne homocoupling. The reaction mechanism involving the formation of the di-copper(II)-alkynyl intermediate, reductive elimination of a diyne, and re-oxidation of reduced copper species by O 2 has been proposed.

Homogeneous and Heterogeneous Performances of Pyridinium Ionic Liquids in the Allylic Oxidation of Ionone-like Dienes

The combination of relatively low-cost ionic liquids, simple copper salt, and terminal oxidant tert-butyl hydroperoxide provided an efficient and environmentally friendly approach to the preparation of ionone-like dienones. Six pyridinium ionic liquids were evaluated in allylic oxidation of α-ionone and β-ionone. The 60%–70% yields of 3-oxo-α-ionone were obtained with 0.02–0.20 mmol of CuCl 2·2H 2O as catalyst, 3–5 mmol of tert-butyl hydroperoxide as oxidant and 1 g of [Bpy]PF 6 as solvent for 4–20 h at 60°C. The facile recovery and recycle of catalyst were also achieved. More significantly, peculiar phase behaviors of [Bpy]PF 6 and [Epy]PF 6 offered the catalytic system advantages of homogeneous reaction and heterogeneous separation. Scanning electron microscope (SEM) images of [Bpy]PF 6 provided evidences for the behaviors. Transmission electron microscope (TEM) micrographs showed copper salt nanoparticles catalyst formed and stabilized in pyridinium ionic liquids.

Enzyme‐Free Quinone Crosslinking Reaction for Proteins: A Macromolecular Characterization Study Using Gelatin

To mimic the quinone hardening of extracellular proteins in invertebrates, we investigated an enzyme-free crosslinking of gelatin by HQ in a neutral aqueous phase. The mixture was rapidly transformed to a yellowish brown, thermally and mechanically stable hydrogel in the presence of a simple copper(II) salt. A dehydrated thin film made of the mixture was flexible, tough, and showed a large ultimate breaking force. Physicochemical examination of the gel suggested that the basic amino acid residues (lysine, hydroxylysine, and histidine) of the protein were modified by the quinone ring to form 2-6 crosslinks per protein. The enzyme-free crosslinking reaction is discussed with consideration of a copper(II) ion-catalyzed oxidation of HQ and the hydroquinone/protein adducts.

ChemInform Abstract: Catalyzed Imidation of Tertiary Amines by Simple Copper Salts.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Thieme Chemistry Journal Awardees - Where Are They Now? Aerobic Oxidative Coupling of Tertiary Amines with Silyl Enolates and Ketene Acetals

Cyclic tertiary amines can be oxidatively coupled with a variety of silyl enol ethers or ketene acetals to furnish tertiary Mannich bases. The reactions are catalyzed by simple copper salts employing elemental oxygen as the oxidant.

Catalyzed Imidation of Tertiary Amines by Simple Copper Salts

AbstractCopper salt catalyzed imidation of tertiary amines by using sulfonyl azides as the nitrogen source was achieved with moderate to high yields. Formation of the carbon–nitrogen bond occurred chemoselectively with the use of a simple and inexpensive catalyst under moderate conditions, with a simple workflow, and with easy preparation of the nitrogen precursors.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Highly efficient Cu-catalyzed oxidative coupling of tertiary amines and siloxyfurans

A mild, selective, and efficient protocol for the synthesis of γ-aminoalkyl butenolides via the oxidative coupling between tertiary amines and siloxyfurans catalyzed by simple copper salts was developed. Compared with the reported method, our method employs copper catalyst instead of the expensive rhodium catalyst. Besides TBHP, both O 2 and H 2O 2 can also be utilized as oxidant to effect the coupling.

A Mild and Efficient Method for N‐Arylnucleobase Synthesis via the Cross‐Coupling Reactions of Nucleobases with Arylboronic Acids Catalyzed by Simple Copper Salts

AbstractA simple and efficient copper‐salt catalyzed N‐arylation of nucleobases is reported. In a mixed solvent of MeOH and H2O, the coupling products were obtained in moderate to excellent yields at room temperature within a short time. A variety of substituted N‐aryl nucleobases can be prepared through this procedure.

Synthesis of tetrasubstituted furans via In-catalyzed propargylation of 1,3-dicarbonyl compounds-cyclization tandem process

An efficient method to synthesize tetrasubstituted furans using simple starting materials such as propargylic alcohols and 1,3-dicarbonyl compounds has been developed. It was discovered that InCl 3 could catalyze this transformation efficiently while other simple iron, copper and silver salts were proven to be ineffective.

α‐Amidation of Cyclic Ethers Catalyzed by Simple Copper Salt and a Mild and Efficient Preparation Method for α,ω‐Amino Alcohols.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

α-Amidation of Cyclic Ethers Catalyzed by Simple Copper Salt and a Mild and Efficient Preparation Method for α,ϖ-Amino Alcohols

Copper(II) trifluoromethanesulfonate catalyzed the amidation of cyclic ethers with iminoiodanes under mild conditions (CH2Cl2, 40 degrees C) with good yields (up to 86% based on 97% conversion) and selectivity (only alpha-amino products were found). Subsequently, the tosylamidated products could undergo a reductive ring-opening reaction to give alpha,omega-amino alcohols.

Structural analysis of Cu(II) ligation to the 5′-GMP nucleotide by pulse EPR spectroscopy

Simple copper salts are known to denature poly d(GC). On the other hand, copper complexes of substituted 1,4,7,10,13-pentaazacyclohexadecane-14,16-dione are able to convert the right-handed B form of the same DNA sequence to the corresponding left-handed Z form. A research program was started in order to understand why Cu(II) as an aquated ion melts DNA and induces the conformational change to Z-DNA in the form of an azamacrocyclic complex. In this paper, we present a continuous wave and pulse electron paramagnetic resonance study of the mononucleotide model system Cu(II)-guanosine 5'-monophosphate . Pulse EPR methods like electron-nuclear double resonance and hyperfine sublevel correlation spectroscopy provide unique information about the electronic and geometric structure of this model system through an elaborate mapping of the hyperfine and nuclear quadrupole interactions between the unpaired electron of the Cu(II) ion and the magnetic nuclei of the nucleotide ligand. It was found that the Cu(II) ion is directly bound to N7 of guanosine 5'-monophosphate and indirectly bound via a water of hydration to a phosphate group. This set of experiments opens the way to more detailed structural characterization of specifically bound metal ions in a variety of nucleic acids of biological interest, in particular to understand the role of the metal-(poly)nucleotide interaction.

Synthesis, X-ray crystal structures and biomimetic and anticancer activities of novel copper(II)benzoate complexes incorporating 2-(4′-thiazolyl)benzimidazole (thiabendazole), 2-(2-pyridyl)benzimidazole and 1,10-phenanthroline as chelating nitrogen donor ligands

Cu(BZA) 2(EtOH) 0.5 ( 1) was generated by the reaction of copper(II) hydroxide with benzoic acid (BZAH). [Cu(TBZH) 2(BZA)](BZA) · 0.5TBZH · H 2O ( 2) and [Cu(2-PyBZIMH)(2-PyBZIM)(BZA)] · 1.66EtOH ( 3) were obtained when 1 reacted with Thiabendazole (TBZH) and 2-(2-pyridyl)benzimidazole (2-PyBZIMH), respectively. [Cu(BZA) 2(phen)(H 2O)] ( 4) was isolated from the reaction of benzoic acid and 1,10-phenanthroline (phen) with copper(II)acetate dihydrate. Molecular structures of 2, 3 and 4 were determined crystallographically. 2 and 3 are hydrogen bonded dimers and trimers, respectively. The copper centres in complexes 2 and 3 are bis-chelate derivatives that have N 4O ligation and their geometry is very similar being approximately square-pyramidal. However whereas in complex 2 both TBZH ligands are neutral in 3 one of the 2-PyBZIMH chelators is deprotonated on each copper. The structural results for 4 represent a re-examination of this crystallographically known compound for which no hydrogen atom coordinates have been previously reported. It crystallises as a hydrogen bonded dimmer and is a mono-chelate of phen with each copper centre possessing N 2O 3 ligation and square pyramidal geometry. The catalase and superoxide dismutase (SOD) activities of the four complexes along with those of the known phenanthroline complexes [Cu(mal)(phen) 2] and [Cu(phendione) 3](ClO 4) 2 (malH 2 = malonic acid and phendione = 1,10-phenanthroline-5,6-dione) were investigated. Complexes 1– 4, the metal free ligands and a simple copper(II) salt were assessed for their cancer chemotherapeutic potential against the hepatocellular carcinoma (Hep-G 2) and kidney adenocarcinoma (A-498) cell lines. TBZH, 2-PyBZIMH and benzoic acid when uncoordinated to a metal centre offer poor chemotherapeutic potential. copper(II) benzoate is significantly more active than the free acid. The bis-chelate derivatives [Cu(TBZH) 2(BZA)](BZA) · 0.5TBZH · H 2O ( 2) and [Cu(2-PyBZIMH)(2-PyBZIM)(BZA)] · 1.66EtOH ( 3) elicit a significant cytotoxic response to the cancer cell lines tested. Replacing TBZH and 2-PyBZIMH with phen to give [Cu(BZA) 2(phen)(H 2O)] ( 4) does not significantly increase the anti-cancer activity.

The Allylic Oxidation of Ionone-Like Dienes by Nanoscale Copper Catalyst in Imidazolium Ionic Liquids

The catalytic system generated from ionic liquids, simple copper salts and terminal oxidant tertbutyl hydroperoxide provided an efficient protocol for the allylic oxidation of ionone-like dienes to corresponding enones. Optimal conditions, short reaction time, and good yields were obtained. Copper nanoparticles were found to be effective catalysts for the oxidation by TEM. Keywords: Allylic oxidation, ionone-like dienes, copper salt, nanoparticles, tert-butyl hydroperoxide, imidazolium ionic liquids

A Simple Copper Salt Catalyzed Synthesis of Unsymmetrical Diaryl Selenides and Tellurides from Arylboronic Acids with Diphenyl Diselenide and Ditelluride.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Copper‐Catalyzed Cross‐Coupling Reactions of Nucleobases with Arylboronic Acids: An Efficient Access to N‐Arylnucleobases

AbstractAn efficient avenue for the direct N‐arylation of nucleobases with arylboronic acids that is catalyzed by simple copper salts was discovered. The N‐arylnucleobases were obtained in excellent yields at room temperature within 45 min when methanol and water were used as a mixed solvent. Under these conditions, the coupling reaction tolerates both electron‐donating and electron‐withdrawing substituents at the o‐, m‐, or p‐positions of phenylboronic acid and gives the corresponding coupling products in moderate to excellent yields. Experimental results show that this route is the most efficient, facile, and mild method for the synthesis of N‐arylnucleobases. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

The structural definition of adducts of stoichiometry MX:dpex (2:3) (∞), M = Cu I, Ag I, X = simple anion, dpex = Ph 2E(CH 2) xEPh 2, E = P, As

Single crystal X-ray structural characterizations are recorded for a number of adducts of MX:dpex (2:3) stoichiometry (MX = simple univalent copper or silver salt; dpex = Ph 2E(CH 2) x EPh 2 (E = P, As)). CuX:dppe (2:3) (X = Cl, Br, I, CN) are binuclear [(dppe- P, P′)CuX( P-dppe- P′)CuX( P, P′-dppe)], all centrosymmetric. AgX:dpex (2:3) (dpex = ‘dpae’ (Ph 2As(CH 2) 2AsPh 2), X = Br, F 3CCO 2 (= ‘tfa’), F 3CSO 3 (≡ ‘tfs’); dpex = ‘dpape’ (Ph 2As(CH 2) 2PPh 2), X = CN, SCN, OClO 3) are one-dimensional polymers ⋯– E′) 1AgX( E-dpex- E′) 2-AgX( E-dpex- E′) 1AgX⋯, P, As sites scrambled in the latter. AgNO 3:dpam (2:3) is also a one-dimensional polymer, ⋯Ag O·NO· OAg( As-dpam- As)Ag O·NO· OAg⋯ (‘dpam’ ≡ Ph 2As(CH 2) 2AsPh 2). AgX:dpae (2:3) (X = I, CN, ClO 4, NO 3) and AgX:dpape (2:3) (X = Br, I, NO 3) are two-dimensional polymers with large 30-membered macrocyclic rings; similar webs are found for dppx ligands in AgOH:dppb (2:3) and AgNCO, Agtfa:dpph (2:3) with 42- and 54-membered rings. Complexes AgX:dpape (1:3) (X = Cl, Br) are defined as mono-nuclear [XAg(Ph 2 P(CH 2) 2AsPh 2) 3] arrays, the unidentate ligands predominantly P-bound. Synthetic procedures for the adducts are reported, selected compounds being characterized both in solution ( 1H, 31P NMR, ESI MS) and in the solid state (IR).

Aerobic Oxidative Coupling of 2‐Naphthols by Simple Copper Salts: A Highly Efficient Catalytic System in the Absence of Ligand or Carrier.

ChemInformVolume 36, Issue 48 Isocyclic Compounds Aerobic Oxidative Coupling of 2-Naphthols by Simple Copper Salts: A Highly Efficient Catalytic System in the Absence of Ligand or Carrier. Shi-Yong Zhang, Shi-Yong Zhang Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorJing-Bo Lan, Jing-Bo Lan Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorXiao-Yu Su, Xiao-Yu Su Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorSheng-Jin Guo, Sheng-Jin Guo Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorLi Chen, Li Chen Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorJing-Song You, Jing-Song You Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorRu-Gang Xie, Ru-Gang Xie Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this author Shi-Yong Zhang, Shi-Yong Zhang Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorJing-Bo Lan, Jing-Bo Lan Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorXiao-Yu Su, Xiao-Yu Su Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorSheng-Jin Guo, Sheng-Jin Guo Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorLi Chen, Li Chen Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorJing-Song You, Jing-Song You Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this authorRu-Gang Xie, Ru-Gang Xie Dep. Chem., Sichuan Univ., Chengdu 610064, Sichuan, Peop. Rep. ChinaSearch for more papers by this author First published: 02 November 2005 https://doi.org/10.1002/chin.200548109Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume36, Issue48November 29, 2005 RelatedInformation

Aerobic Oxidative Coupling of 2-naphthols by Simple Copper Salts: A Highly Efficient Catalytic System in the Absence of Ligand or Carrier

A ligand-free or carrier-free copper salt system that catalysed aerobic oxidative coupling of 2-naphthols has been established. 1,1′-Bi-2-naphthols were afforded in excellent yields in methanol in the presence of 5 mol % copper (| or ||) salts. The coupling reaction could also be performed very well in aqueous solvents.

14-Hydroxylation of Opiates: Catalytic Direct Autoxidation of Codeinone to 14-Hydroxycodeinone

Codeinone (3) was efficiently and directly converted to 14-hydroxycodeinone (1) by catalytic air oxidation in aqueous solution. A number of simple manganese and copper salts were identified to be effective catalysts, including MnSO4, KMnO4, and CuSO4. An appropriate reducing agent, such as sodium thiosulfate, is required in the reaction mixture presumably for the reduction of a detrimental peroxide intermediate. This discovery allows the more abundant codeine to be employed as the starting material for the synthesis of 14-hydroxylated opiate drugs without recourse to a thebaine-like intermediate. These discoveries were inspired from our study of microbial transformation of codeine to 14-hydroxycodeine by Mycobacterium neoaurum, where we found the actual 14-hydroxylation step is a chemical reaction rather than an enzymatic reaction, as previously believed.