Coupling Reaction Of Terminal Alkynes Research Articles

Synthesis of Multinuclear Copper Complexes Bridged by Diquinolylamidinates and Their Application to Copper-Catalyzed Coupling of Terminal Alkynes and Aryl, Allyl, and Benzyl Halides

A dinuclear copper complex containing N,N′-diquinolylformamidinate and a tetranuclear copper complex containing N,N′-diquinolylacetamidinate were synthesized. The structure of complexes was confirmed by X-ray analysis, showing that copper atoms were bridged by amidinates and hydroxo or oxo ligands. The multinuclear copper complexes were effective for the coupling reactions of terminal alkynes and aryl, allyl, and benzyl halides.

Cu-modified hydroxy-apatite as catalyst for Glaser–Hay C[sbnd]C homo- coupling reaction of terminal alkynes

The oxidative Glaser–Hay coupling reaction of terminal alkynes is a very important reaction in organic chemistry to achieve the synthesis of diyne compounds. In general the reaction is performed under homogeneous conditions using Cu(I) or Cu(II) salts in the presence of a reagent such as tetramethylethylenediamine (TMEDA), which can bind to copper ions, an organic base and dioxygen. Although this reaction is known for a long time, the mechanism is still under discussion. Pursuing our investigations on the use of apatites as catalysts for organic reactions we highlight in this work how it is possible to catalyze the Glaser–Hay reaction under heterogeneous conditions using a Cu-modified hydroxyapatite (Cu–HAp). With several para-substituted phenyl-acetylenes and alkynols we show that Cu–HAp acts as catalyst for CC coupling reactions leading to diyne derivatives in high yields without using auxiliary chelating molecules and organic bases. These heterogeneous conditions allow an easy recovery of the catalyst and simplify the purification work-up.

2,5‐Bis(2‐(diphenylphosphino)phenyl)‐1,3,4‐oxadiazole ligands and their Cu(I) complexes for Sonogashira coupling reaction

Two diphosphane ligands – 2,5‐bis(2‐(diphenylphosphino)‐5‐R)phenyl)‐1,3,4‐oxadiazole (L1, R = H, L2, R = OMe) and their binuclear complexes, L1Cu and L2Cu, were prepared and characterized. The molecular structures of L1Cu and L2Cu, as perchlorate salts, were established by X‐ray crystallography, which showed them to be binuclear complexes with each Cu atom tetrahedrally coordinated by two P atoms and two N atoms. The ligands and their Cu(I) complexes catalyzed Sonogashira coupling reactions of iodobenzene with phenylacetylene in the presence of K2CO3 under Pd‐free conditions. Coupling reactions catalyzed by L1 or L2 with Cu(MeCN)4ClO4 in situ exhibited better yields than those by the corresponding Cu(I) complexes L1Cu or L2Cu. Detailed studies showed L1 or L2 with Cu(MeCN)4ClO4 to be suitable catalysts for the coupling reaction of terminal alkynes and aryl halides. The coupling reactions of aryl iodides with electron‐withdrawing groups showed better results. Copyright © 2014 John Wiley & Sons, Ltd.

Nano copper(i) oxide–zinc oxide catalyzed coupling of aldehydes or ketones, secondary amines, and terminal alkynes in solvent-free conditions

A simple, efficient, and environmentally benign method has been described for the synthesis of propargylamines through a one-pot three-component coupling reaction of terminal alkynes, aldehydes or ketones, and secondary amines in excellent isolated yields, under solvent-free conditions, using a catalytic amount of nano Cu2O–ZnO as the recyclable, and heterogeneous catalyst. The catalyst can be reused in further catalytic reactions, and it was found that its activity remained largely unchanged for ten successive runs. The catalyst was characterized by using powder X-ray diffraction (XRD), a transmission electron microscopy (TEM), a scanning electron microscopy (SEM), BET surface area measurement and FT-IR spectroscopy.

Silica nanospheres supported diazafluorene iron complex: an efficient and versatile nanocatalyst for the synthesis of propargylamines from terminal alkynes, dihalomethane and amines

A novel silica nanosperes supported diazafluorene iron complex has been fabricated and found to be effective in three-component coupling reaction of terminal alkynes, dichloromethane and amines.

ChemInform Abstract: Palladium Chloride—Cryptand‐22 Complex: An Efficient Catalyst for the Copper‐, Phosphorus‐, and Solvent‐Free Synthesis of Ynones.

The palladium chloride–cryptand-22 complex was found to be an efficient catalyst for the copper-, phosphorus-, and solvent-free coupling reaction of terminal alkynes with different acyl chlorides in the presence of triethylamine as base, at room temperature and under aerobic conditions. The simple, mild, and green procedure, short reaction times, and moderate to excellent yields make this method well-suited for ynone synthesis. .

Nickel‐catalyzed three‐component coupling reaction of terminal alkynes, dihalomethane and amines to propargylamines

Direct C―H and C―halogen activation is an important and practical task in C―C, C―N bond formation reactions using alkynes. Propargylic amines are synthetically versatile intermediates for the preparation of many nitrogen‐containing biologically active motifs. Herein, a 15 mol% Ni(py)4Cl2/bipyridine‐catalyzed three‐component coupling reaction of alkynes, halomethane and amines through C―H and C―halogen activation was developed for the facile synthesis of propargylic amines. Tetramethylguanidine shows excellent basicity in acetonitrile and works under mild conditions. The reaction has very good functional group tolerance to aliphatic and aromatic alkynes. Copyright © 2013 John Wiley & Sons, Ltd.

A novel copper-catalyzed synthesis of functionalized alkynyl imidates and alkynyl thioimidates

A copper-catalyzed one-pot synthesis of alkynyl imidates and alkynyl thioimidates via coupling reactions of terminal alkynes with trichloroimidates, generated in situ from trichloroacetonitrile and benzyl alcohols or thiols, is reported.

Enaminone ligand-assisted homo- and cross-coupling of terminal alkynes under mild conditions

Abstract Copper-catalyzed oxidative coupling reactions of terminal alkynes have been performed at room temperature by using enaminone as effective ligand. Both symmetrical and unsymmetrical 1,3-diynes bearing various functional groups have been synthesized in moderate to excellent yields via homo- and cross-coupling reactions.

A Facile Synthesis of 4,6,7,8,8a,9‐Hexahydropyrrolo[1,2‐a][1,2,3]triazolo[1,5‐d]pyr­azines by a Three‐Component Coupling Reaction Followed by Intramolecular 1,3‐Dipolar Cycloaddition

AbstractA practical and efficient two‐step protocol for the synthesis of several new 4,6,7,8,8a,9‐hexahydropyrrolo[1,2‐a][1,2,3]triazolo[1,5‐d]pyrazines is described. The first step involves the AuBr3‐catalyzed three‐component coupling reaction of terminal alkynes, aldehydes, and amines under solvent‐free conditions to provide the requisite propargylamines. The reaction tolerates a high structural diversity, requires only short reaction times, gives high diastereoselectivities, and is environmentally benign. Furthermore, the propargylamine products undergo catalyst‐free intramolecular azide–alkyne [3 + 2] dipolar cycloaddition reactions to give the 4,6,7,8,8a,9‐hexahydropyrrolo[1,2‐a][1,2,3]triazolo[1,5‐d]pyrazines in excellent yields and with excellent diastereoselectivities.

Palladium chloride–cryptand-22 complex: an efficient catalyst for the copper-, phosphorus-, and solvent-free synthesis of ynones

The palladium chloride–cryptand-22 complex was found to be an efficient catalyst for the copper-, phosphorus-, and solvent-free coupling reaction of terminal alkynes with different acyl chlorides in the presence of triethylamine as base, at room temperature and under aerobic conditions. The simple, mild, and green procedure, short reaction times, and moderate to excellent yields make this method well-suited for ynone synthesis. .

CuSO4·5H2O-catalyzed alkynylphosphonates formation — An efficient coupling reaction of terminal alkynes with H-phosphonates

It was recently discovered that easily available CuSO4·5H2O could be employed as an efficient catalyst towards the coupling reactions of terminal alkynes with H-phosphonates, which finally led to the formation of a large variety of novel alkynylphosphates.

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.

ChemInform Abstract: An Efficient and Recyclable Silica‐Supported Carbene—Cu(II) Catalyst for the Oxidative Coupling Reaction of Terminal Alkynes with H‐Phosphonates under Base‐Free Reaction Conditions.

AbstractTitle reaction proceeds smoothly for a variety of aromatic and aliphatic terminal alkynes to give the corresponding alkynylphosphonates (III) and (V) in good yields.

C-C and C-O Coupling Reactions of Terminal Alkynes by a Water Soluble Organoiridium Electron-transfer Mediator in Thin Layer of Water on Gold Electrode

An electrochemical reduction process is described for the rapid and efficient conversion of terminal alkynes into useful products. Terminal alkynes (HC≡CR; R = C 6 H 5 , p -C 6 H 4 CH 3 , CH 2 C 6 H 5 , C 6 H 9 ) were hydrated and dimerized by cathodic reduction of catalytic amount (5 %) of [Cp * Ir(NCMe) 2 (PAr 3 )](OTf) 2 , 1 , ( E pc = −620 mV vs Ag/AgCl) through an aqueous/nonaqueous interface. Thin aqueous layer containing water-soluble compound 1 was formed on gold electrode. The cathodic reduction current height of 1 increases as increasing the concentration of terminal alkynes. The electrolysis of 1 while contacting with terminal alkynes containing organic solvent produced ketones, aldehydes and dimerized enyne products from terminal alkyne/water reaction systems. A new micro-scale electrocatalysis technique is depicted.

An efficient and recyclable silica‐supported carbene–Cu(II) catalyst for the oxidative coupling reaction of terminal alkynes with H‐phosphonates under base‐free reaction conditions

The oxidative coupling reactions of terminal alkynes with H‐phosphonates were explored using SiO2−NHC−Cu(II) (5.0 mol%) as catalyst at room temperature under base‐free reaction conditions. The reactions of a variety of terminal alkynes with H‐phosphonates generated the corresponding alkynylphosphonate products in good to excellent yields. In addition, SiO2−NHC−Cu(II) could be recovered and recycled for six consecutive trials without significant loss of its reactivity. Copyright © 2011 John Wiley & Sons, Ltd.

Environmentally Benign Microwave-Assisted Sonogashira Preparation of Aromatic Compounds

An efficient Sonogashira-type coupling reaction of terminal alkynes and aryl bromides by microwave activation with short reaction time under mild conditions are presented. It is illustrated herein that the traditional Sonogashira coupling reaction can be achieved with a much more efficient yet environmentally friendly condition. In contrary to the usually required 10 mol% Pd loading and the use of conventional heating at 60 °C for 24 h in order for a reaction to proceed satisfactorily, with a 100 W microwave activation, the reaction of terminal alkynes with substituted aryl bromides can be achieved with only a 2.5 mol% Pd in 10 min. The yield was improved with microwave irradiation.

Copper(II) chloride-catalyzed Glaser oxidative coupling reaction in polyethylene glycol

Polyethylene glycol was shown to be an environmentally benign reaction medium for the copper(II) salt -catalyzed Glaser coupling reaction of terminal alkynes. In particular, oxygen as the sole oxidant worked very well for arylacetylenes even in short reaction time. The product was easily separated by extraction and the catalytic system could be reused four times without significant loss of reactivity.

Ligand-Free Copper Oxide Nanoparticle-Catalyzed Sonogashira Coupling Reaction

The catalytic Sonogashira coupling reaction of terminal alkynes and aryl halides is developed using copper(II) oxide nanoparticles as catalyst in dimethyl sulfoxide. The procedure is experimentally simple, general, efficient, and free from addition of external cocatalysts or chelating ligands.

ChemInform Abstract: Using Pd‐Salen Complex as an Efficient Catalyst for the Copper‐ and Solvent‐Free Coupling of Acyl Chlorides with Terminal Alkynes under Aerobic Conditions.

Abstract The palladium–salen complex palladium(II) N,N′-bis{[5-(triphenylphosphonium)-methyl]salicylidene}-1,2-ethanediamine chloride was found to be a highly active catalyst for the copper- and solvent-free coupling reaction of terminal alkynes with different acyl chlorides in the presence of triethylamine as base, giving excellent ynones under aerobic conditions.