Polymer-supported Copper Research Articles

C–N Coupling Reaction with a Quinoxaline-Based Porous Organic Polymer-Supported Copper Catalyst

C–N Coupling Reaction with a Quinoxaline-Based Porous Organic Polymer-Supported Copper Catalyst

Corrigendum to “Fiber-polyquaterniums@Cu(I) as recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions” [J. Ind. Eng. Chem. 69 (2019) 387–396

Corrigendum to “Fiber-polyquaterniums@Cu(I) as recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions” [J. Ind. Eng. Chem. 69 (2019) 387–396

Triazinetriamine-derived porous organic polymer-supported copper nanoparticles (Cu-NPs@TzTa-POP): an efficient catalyst for the synthesis of N-methylated products via CO2 fixation and primary carbamates from alcohols and urea

Copper nanoparticles incorporated triazinetriamine derived porous organic polymer based catalyst was synthesized for catalytic production N-methylated amines and primary carbamates.

Fiber-polyquaterniums@Cu(I) as recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions

Herein, a newly designed and synthesized fiber-supported polyquaterniums@Cu(I) served as efficient and recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions, is reported. The fiber-supported copper complex catalyst was prepared systematically from commercially available polyacrylonitrile fiber, and characterized detailedly by elemental analysis, FTIR spectroscopy, mechanical properties, and SEM during both of the preparation and utilization processes. Moreover, the fiber-supported polyquaterniums@Cu(I) has been verified to possess high catalytic activities for the homocoupling of terminal alkyne in ethyl acetate (10 samples yields 83–99%, 10 cycles from 98% to 95%), A3 coupling of alkyne, aldehyde and amine in toluene (10 samples yields 81–94%, 10 cycles from 94% to 90%), and click chemistry of CuAAC reactions in water (10 samples yields 82–99%, 21 cycles from 97% to 96%). Furthermore, the newly developed fiber catalyst in spinning basket reactor displayed excellent stability and recyclability, and the concise and effective gram-scalable operation has extensive application prospect on chemical productions.

Coupling of Acid Chlorides with Alkynes on Polymer-Supported Copper Nanoparticles

Key words acid chlorides - alkynes - Sonogashira coupling - nanoparticles - mesoporous materials - copper catalysis

Application of the polyacrylonitrile fiber as a novel support for polymer-supported copper catalysts in terminal alkyne homocoupling reactions

A commercially available synthetic polyacrylonitrile fiber, capable of acting as a novel support for polymer-supported copper catalyst in terminal alkyne homocoupling reactions, is presented. Detailed characterization by inductively coupled plasma (ICP) analysis, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) confirmed the changes and stability of the fiber catalyst during the modification and utilization processes. Moreover, the catalytic reactions proceeded at room temperature using air as a green oxidant to afford nearly quantitative yields (95–99%); the fiber catalyst has shown excellent activity and superior recyclability (over 16 cycles); and the procedure is operationally simple and amenable to the gram scale in continuous-flow processing. Furthermore, the prominent features (high strength, good flexibility, etc.) of the polyacrylonitrile fiber make the fiber-supported catalyst very attractive for fixed-bed reactors in the chemical industry.

Huisgen Cycloaddition on a Polymer-Supported Copper Catalyst

Key words cross-linked polymers - Huisgen cycloaddition - ionic liquids - copper

ChemInform Abstract: Polymer‐Anchored Copper(II) Complex: An Efficient Reusable Catalyst for the Synthesis of Propargylamines

Abstractvia a three‐component coupling reaction

A Polymer-Supported Copper Complex for Asymmetric Henry Reaction

Key words asymmetric Henry reaction - copper complexes - copolymers - heterogeneous catalysis

Recyclable Porous Polymer‐Supported Copper Catalysts for Glaser and Huisgen 1,3‐Diolar Cycloaddition Reactions

A family of polymer-attached phenanthrolines was prepared from solvothermal copolymerization of divinylbenzene with N-(1,10-phenanthroline-5-yl)acrylamide in different ratios. The polymer-supported copper catalysts were obtained through typical impregnation with copper(II) salts. The polymers and supported copper catalysts have been characterized by N2 adsortion, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TG); they exhibit a high surface area, hierarchical porosity, large pore volume, and high thermal and chemical stabilities. The copper catalyst has proved to be highly active for Glaser homocoupling of alkynes and Huisgen 1,3-diolar cycloaddition of alkynes with benzyl azide under mild conditions at low catalyst loading. The heterogeneous copper catalyst is more active than commonly used homogeneous and nonporous polystyrene-supported copper catalysts. In particular, the catalyst is easily recovered and can be recycled at least ten times without any obvious loss in catalytic activity. Metal leaching was prevented due to the strong binding ability of phenanthroline and products were not contaminated with copper, as determined by ICP analysis.

Liquid-phase catalytic oxidation of organic substrates by a recyclable polymer-supported copper(II) complex

Chloromethylated polystyrene beads cross-linked with 6.5 % divinylbenzene were functionalized with 2-(2′-pyridyl) benzimidazole (PBIMH) and on subsequent treatment with Cu(OAc)2 in methanol gave a polymer-supported diacetatobis(2-pyridylbenzimidazole)copper(II) complex [PS-(PBIM)2Cu(II)], which was characterized by physicochemical techniques. The supported complex showed excellent catalytic activity toward the oxidation of industrially important organic compounds such as phenol, benzyl alcohol, cyclohexanol, styrene, and ethylbenzene. An effective catalytic protocol was developed by varying reaction parameters such as the catalyst and substrate concentrations, reaction time, temperature, and substrate-to-oxidant ratio to obtain maximum selectivity with high yields of products. Possible reaction mechanisms were worked out. The catalyst could be recycled five times without any metal leaching or much loss in activity. This catalyst is truly heterogeneous and allows for easy work up, as well as recyclability and excellent product yields under mild conditions.

Modification of poly(vinyl chloride) with pendant metal complex for catalytic applications

Abstract Poly(vinyl chloride) was modified to develop an alternative support for the preparation of polymer-supported catalysts. Commercially available poly(vinyl chloride) was synthetically modified to a polymer containing pendant primary amino groups. The Schiff-base of salicylaldehyde and the amino polymer were prepared and were used as the ligands in the synthesis of a polymer-supported copper complex. The polymer-supported ligand and catalysts were characterized by various physical methods. The polymer with the pendant copper complex was able to catalyze the one-pot three-component Mannich reaction between aldehydes, ketones and anilines under mild and environmentally friendly conditions. The catalyst can be recovered by simple filtration and is reusable.

Polymer-Supported Azide and Copper(I): Green Reusable Reagent and Catalyst for Click Cyclization

In this work, polymer-supported copper(I) iodide catalyst and macroporous polymer-supported azide reagent were used to simplify the synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from α-bromo ketones/amides/esters following green chemistry principles. This new one-pot protocol facilitates the workup of the reaction and provides the products in short times and excellent yields. Heterogeneous catalyst and reagent can be reused at least for five runs without significant yield decreases.

Terminal alkyne homocoupling reactions catalyzed by an efficient and recyclable polymer-supported copper catalyst at room temperature under solvent-free conditions

A highly efficient protocol for terminal alkyne homocoupling reaction to 1,4-disubstituted 1,3-diynes using a polymer-supported copper catalyst at room temperature under solvent conditions is presented. The reaction proceeds smoothly to provide the corresponding products in excellent to high yields within 10–20 min.

Olefin epoxidation with tert-butyl hydroperoxide catalyzed by functionalized polymer-supported copper(II) Schiff base complex

A new polymer-supported Cu(II) Schiff base complex has been synthesized and characterized by elemental (including metal) analysis, FT-IR spectroscopy, UV–Vis diffuse reflectance spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The catalytic performance of this complex was evaluated in the epoxidation of styrene in acetonitrile/N,N-dimethylformamide (9:1) mixture with 70% tert-butyl hydroperoxide as an oxidizing agent under liquid phase reaction conditions for selective synthesis of styrene oxide. Suitable reaction conditions have been optimized by considering the effects of various reaction parameters such as temperature, reaction time, solvent, oxidant, catalyst amount, and styrene to hydroperoxide molar ratio for the maximum conversion of styrene as well as selectivity of styrene oxide. We have also investigated the epoxidation reaction of various olefins under the optimized reaction conditions. Comparison between catalytic activities of the polymer-supported Cu(II) Schiff base complex and its homogeneous analogue showed that the polymer-supported catalyst was more active. This heterogeneous complex was reused for five times. The selectivity of the heterogeneous catalyst does not change even after five times of reusing.

An efficient polymer-supported copper(II) catalyst for the N-arylation reaction of N(H)-heterocycles with aryl halides as well as arylboronic acids

Immobilization of copper onto polystyrene provided a polymer-supported copper(II) catalyst, which was effective in cross-coupling reactions between N-containing substrates and arylboronic acids using methanol as a solvent in air under base-free conditions. This catalyst was also effective in N-arylation of imidazole with aryl halides in DMSO using K2CO3 as a base under nitrogen atmosphere. The catalyst was characterized by physico-chemical and spectroscopic techniques. The product N-arylimidazoles and N-arylbenzimidazoles were isolated in good to excellent yields. This copper catalyst was air stable and could be recycled with minimal loss of activity.

Synthesis, characterization, and catalytic activity of a polymer-supported copper(II) complex with a thiosemicarbazone ligand

A thiosemicarbazone Cu(II) complex anchored to a polystyrene framework has been synthesized and characterized by analytical and spectroscopic techniques. The complex was found to be a highly active catalyst for the oxidation of various organic substrates including alkenes and alcohols using H2O2 as oxidant. The reaction conditions were optimized with respect to temperature, solvent, oxidant, catalyst amount, and substrate to peroxide ratio. The heterogeneous catalyst was reused five times without significant loss of activity. A comparison between the catalytic activities of this polymer-supported Cu(II) complex and its homogeneous analogue was carried out.

Chemoselective preparation of disymmetric bistriazoles from bisalkynes

Best of both worlds, molecules bearing two alkyne groups, activated and unactivated, can selectively react on the activated one in a copper-free version of Huisgen’s reaction to form a first triazole ring, with a good selectivity toward the 1,4-isomer, which is solely isolated by a simple trituration procedure. The other alkyne function is then submitted to the selective reaction using a polymer-supported copper(I) catalyst to form a second triazole ring. This gave access to disymmetric bistriazoles without the need of protection using simple, easy, and fast procedures.

Asymmetric cyanosilylation of ketones catalyzed by recyclable polymer-supported copper(II) salen complexes

Various ketones have undergone asymmetric trimethylsilylcyanation at room temperature with (CH 3) 3SiCN (TMSCN) in the presence of a chiral-supported Cu(salen) complex and Ph 3PO as the catalyst. Aromatic, aliphatic, and heterocyclic ketones have been converted into the corresponding cyanohydrin trimethylsilyl ethers in 83−96% yields with 52−84% ee. Several factors concerning the reactivity and enantioselectivity have been discussed. A double activation where Cu(salen) plays the role of Lewis acid and Ph 3PO acts as a Lewis base is reported. Poly(ethylene glycol) monomethyl ether (MeO-PEG) has been used as a soluble support while Janda Jel (JJ) and Merrifield (MF) resins served as insoluble supports. Each polymer is linked to the salen catalyst through a glutarate spacer. The soluble catalysts were recovered by precipitation with a suitable solvent while the insoluble catalysts were simply filtered from the reaction mixture. The Janda Jel-attached Cu(salen) catalyst could be used for five cycles with the retention of efficiency and the Merrifield-bound Cu(salen) catalyst was found to loose activity with each use.

Reusable polymer-supported copper catalyst for one-pot synthesis of 1-alkyl- and 1-aryl-1,2,3-triazoles: green, simple, and effective

Polymer-supported copper-catalyzed one-pot synthesis of 1,4-disubstituted 1-alkyl- and 1-aryl-1,2,3-triazoles via 1,3-dipolar cycloaddition of alkyl halides or arylboronic acids, sodium azide, and phenylacetylene has been developed. Reactions went smoothly at room temperature using PEG/H2O or methanol as solvent to afford the corresponding triazoles in good to excellent yields. The catalyst could be recovered by simple filtration and reused several times with slightly decrease in its activity.