A3 Coupling Reaction Research Articles

Synthesis, Structure and Catalytic Properties of a Cu(II) Coordination Polymer Constructed from Paddle-Wheel Building Blocks

A novel dinuclear Cu(II) coordination polymer, [Cu(BCPPO)H2O]n (1) [H2BCPPO = bis -4-carboxyphenyl phenyl phosphine oxide], has been synthesized and structurally characterized by single crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, elemental analysis and infrared spectroscopy. As revealed by the single crystal X-ray diffraction, in complex 1, two paddle-wheel-type Cu2 units were connected by two BCPPO ligands to form one-dimensional infinite chain. The A3 coupling reaction of phenylacetylene, aldehyde and amine (piperidine) in the presence of the dinuclear Cu(II) coordination polymer as an efficient heterogeneous catalyst has also been studied. Complex 1 displayed high activity and afforded the corresponding propargylamines with moderate yields.

Amino acid ionic liquid bound copper Schiff base catalyzed highly efficient three component A3-coupling reaction

Amino acid ionic liquid Schiff base derived from dl-threonine and salicylaldehyde was complexed with copper (II) ions and used as an efficient and reusable catalyst for multicomponent synthesis of propargylamines via A3 coupling of aldehydes, amines, and alkynes. The ionic liquid derived catalyst was readily synthesized, reusable and exhibited superior catalytic activity. The synthesized catalyst showed consistent activity for several runs without any significant loss in activity and importantly, no leaching had occurred during this course.

In-situ immobilization of silver nanoparticles on ZSM-5 type zeolite by catechol redox chemistry, a green catalyst for A3-coupling reaction

For the first time in literature, we used a mussel-inspired surface chemistry for the production of propargylamines by the immobilization of silver nanoparticles (AgNPs) on the surface of mesoporous ZSM-5 zeolite. The ZSM-5 zeolite has a large surface area with a porous structure and provides a sufficient reaction space for monodisperse silver nanoparticles, resulting in high catalytic activity for the production of propargylamines with a shorter reaction time. The catalyst was recovered easily and could be used for three cycles without any significant loss in catalytic activity. N2 adsorption/desorption, ICP-AES, XRD, XPS, FE-SEM, TEM and FT-IR experiments were carried out to characterize the heterogeneous catalysts of this study.

Synthesis, structure and multifunctional catalytic properties of a Cu(i)-coordination polymer with outer-hanging CuBr2

A 1D Cu(I)-coordination polymer [(CuL1)(CuBr2), 1] carrying external copper bromide moieties was synthesized. The outer-hanging [CuBr2]− moiety is attached to the 1D Cu(I)-CP backbone via a Cu⋯Cu bonding interaction, which makes it look like a coordination polymer supported CuBr2 species. 1 exhibits excellent multifunctional catalytic activity for phenol acetylation, A3-coupling (aldehyde–alkyne–amine) and styrene oxide methanolysis reactions. Its heterogeneous catalytic nature was confirmed by solution leaching experiment and it can be reused without significant loss of its catalytic activity and selectivity for the above reactions.

Highly efficient three-component coupling reaction catalysed by atomically precise ligand-protected Au38(SC2H4Ph)24 nanoclusters.

The catalytic potential of atomically precise quantum-sized gold nanoclusters (Au38(SC2H4Ph)24) is explored for the three-component coupling of an aldehyde, an alkyne and an amine to synthesize propargylamines. A high catalytic efficiency with a very low loading (0.01 mol%) is achieved. Furthermore, the synergistic effect of the electron-deficient surface (i.e. Auδ+, 0 < δ+ < 1) and the electron-rich Au23 core of the ligand-protected nanoclusters is critical for this catalytic reaction.

Copper nanoparticles supported on starch micro particles as a degradable heterogeneous catalyst for three-component coupling synthesis of propargylamines

Starch supported Cu NPs as a degradable heterogeneous catalyst for A3 coupling reaction.

Silver(I) complexes as efficient source for silver oxide nanoparticles with catalytic activity in A3 coupling reactions

New silver(I) complexes [Ag7(μ4-Cl)(μ3-Cl)2(μ2-Cl)3(MPI)6] (1), and [Ag(μ3-I)(BI)]n (2) [MPI=1-(4-methoxyphenyl)-1H-imidazole; BI=1-Benzylimidazole] have been prepared starting with AgX (X=Cl, I) and 1-(4-methoxyphenyl)-1H-imidazole/1-Benzylimidazole. The complexes have been characterized by elemental analysis, IR, 1H NMR, and electronic absorption spectroscopy. Molecular structure of the complexes 1 and 2 were determined crystallographically. Complex 1 has a twofold axis with Ag3 in special position and bisecting the Ag4–Ag4′ vector. It contains six 1-(4-methoxyphenyl)-1H-imidazole molecules and seven chlorine atoms bridging the seven silver atoms. Complex 2 exists as a one-dimensional (1D) polymeric chain of [(μ3-I)Ag(μ3-I)Ag] fragments bridged via the 1-Benzylimidazole ligand. The weak argentophilic Ag⋯Ag interaction distances in complexes 1 and 2 are 3.1014(4)Å–3.2998(15)Å, respectively. The complexes 1 and 2, yielded silver oxide nanoparticles on pyrolysis and were characterized by PXRD and TEM. The catalytic properties of the resulting silver oxide nanoparticles and the silver(I) complexes have also been studied for A3-coupling of amines, alkynes and aldehydes in microwave which gave moderate to good yields of propargylamines. Silver(I) complexes exhibit higher catalytic activity compared to silver oxide nanoparticles. The silver oxide nanoparticles as well as silver(I) complexes could be separated easily from the reaction mixture and reused at least four to five times without significant loss of the catalytic activity.

ChemInform Abstract: Synthesis of 4‐Alkylidene‐Substituted 1,2,3,4‐Tetrahydroisoquinolines via Palladium‐Catalyzed Carbopalladation/C—H Activation of 2‐Bromobenzyl‐N‐propargylamines.

Tetrasubstituted alkene-based 1,2,3,4-tetrahydroisoquinolines are synthesized via the formation of a cyclic carbopalladation complex followed by C–H bond activation of the sp2 carbon in arenes. This domino reaction proceeds with good selectivity and provides good yields of the products. The requisite starting materials are synthesized by copper(I) iodide catalyzed A3-coupling reactions.

One-Pot Synthesis of Aminoindolizines and Chalcones Using CuI/CSP Nanocomposites with Anomalous Selectivity under Green Conditions

CuI/CSP nanocomposites were found to be efficient and recyclable nanocatalysts for one-pot synthesis of aminoindolizines via A3 coupling reaction in the presence of ethylene glycol (EG) as a recyclable solvent. In contrast, chalcones were isolated when the reaction was performed in the presence of secondary amines such as piperidine, 3-methylpiperidine, pyrrolidine, and piperazine under solvent free conditions. The CuI/CSP was recycled for five times without significant loss in its catalytic activity. The anomalous selectivity in the formation of aminoindolizines and chalcones was dependent on solvents and secondary amines used for the reaction. The present methodology is facile and follows green principles with higher atom economy (94%) and smaller E-factor (0.06).

Sustainable and Versatile CuO/GNS Nanocatalyst for Highly Efficient Base Free Coupling Reactions

A CuO nanoparticles (CuO NPs)/graphene nanosheet (GNS) hybrid was prepared by a very simple method and employed as a nanocatalyst (CuO/GNS) for base free coupling reactions, namely, A3-coupling and aza-Michael reactions. TEM shows that CuO NPs of below ∼35 nm size are homogeneously dispersed on the GNS. Strong adhesion between CuO NPs and GNS was acknowledged by a high Raman ID/IG ratio and XPS result. The BET surface area of CuO/GNS was found to be 66.26 m2 g–1. The EDS and XPS investigations revealed that the weight percentage and chemical state of Cu in CuO/GNS were 4.46% and +2, respectively. Under mild reaction conditions, CuO/GNS exhibited an outstanding catalytic activity in terms of yield, turnover number (TON) and turnover frequency (TOF) toward A3-coupling reaction. A small amount of catalyst (10 mg, 0.7 mol % of Cu) is enough to carry out the reactions with a wide range of substrates. The CuO/GNS is stable, heterogeneous in nature and reusable for at least five times without any significant los...

Green synthesis of CuO nanoparticles by aqueous extract of Anthemis nobilis flowers and their catalytic activity for the A3 coupling reaction

CuO nanoparticles (NPs) were prepared by Anthemis nobilis flowers extract as a reducing and stabilizing agent and employed in catalyzing an aldehyde–amine–alkyne coupling reaction. The synthesized CuO NPs was characterized by SEM, EDS, XRD, FT-IR and UV–visible techniques. A diverse range of propargylamines were obtained in a good to high yield. Furthermore, the separation and reuse of CuO NPs was very simple, effective and economical.

Development of gold nanoparticle-fungal hybrid based heterogeneous interface for catalytic applications

Unsupported and free gold nanoparticles (Au NPs) represent great potential in the field of catalysis. However, shortcomings like agglomeration and loss of the precious catalyst has encouraged the development of supported Au NPs as catalyst with increased activity, selectivity, ease of separation from the reaction mixture and recyclability. The present work demonstrates an eco-friendly, rapid and facile synthesis of catalytically active bio-supported Au NPs using a soil fungus, Aspergillus japonicus AJP01. The dual role of the fungal isolate in synthesis as well as immobilization of Au NPs is the remarkable feature of the study. The fungus successfully reduced Au(III) into Au NPs containing principally Au(0) with a small percentage of Au(I) as revealed by X-ray photoelectron spectroscopy. The particles were spherical in shape and well distributed on fungal mycelia with size ranging predominantly between 15 and 20nm. The as-synthesized nanoparticle-fungal hybrid was found to be highly efficient in catalyzing sodium borohydride mediated reduction reactions of 4-nitrophenol and hexacyanoferrate(III). The versatility of the bionanocatalyst was further demonstrated by catalyzing the A3 coupling reactions for the synthesis of propargylamines.

Synthesis of 4-Alkylidene-Substituted 1,2,3,4-Tetrahydroisoquinolines via Palladium-Catalyzed Carbopalladation/C–H Activation of 2-Bromobenzyl-N-propargylamines

Tetrasubstituted alkene-based 1,2,3,4-tetrahydroisoquinolines are synthesized via the formation of a cyclic carbopalladation complex followed by C–H bond activation of the sp2 carbon in arenes. This domino reaction proceeds with good selectivity and provides good yields of the products. The requisite starting materials are synthesized by copper(I) iodide catalyzed A3-coupling reactions.

ChemInform Abstract: Copper(I)‐Catalyzed Decarboxylative Coupling of Propiolic Acids with Secondary Amines and Aldehydes.

An efficient microwave-assisted synthesis of tertiary propargylamines has been developed by copper(I)-catalyzed decarboxylative A3-coupling reaction of an alkynylcarboxylic acid with a secondary amine and an aldehyde. A wide range of diversely substituted propargylamines could be synthesized in high yields. The optimal reaction conditions are also effective for 3-alkylpropiolic acids and for terminal propiolic acid.

Synthesis, Crystal Structure of Mg(II) Complex Material and its Application as Catalysts for A3 Coupling Reaction

The ligand of 1, 2-phenylenedioxydiacetic acid (HL) has been employed to react with MgCl2·6H2O in water/ethanol solution (v:v = 1:1), to yield a novel Mg(II) complex [MgL(H2O]3·3.5H2O. The complex was characterized by infrared spectroscopy and single crystal X-ray diffraction structural analysis. The results show that the Mg(II) complex belongs to monoclinic, space group C2/c with a = 2.9160(6) nm, b = 0.67617(14) nm, c = 1.7319(4) nm, β = 109.06(3)°, V= 3.2275(11) nm, Z = 8, Dc= 1.562 µg·m-3, µ = 0.184 mm, F (000) = 1560, and final R1 = 0.0703, ωR2= 0.2256. The complex molecules form a 3D network structure through hydrogen bonds and π-π stack. The A3 coupling reaction of phenylacetylene, aldehyde and amine (piperidine) in the presence of Au@Mg(II) complex as an efficient heterogeneous catalyst has been studied.

Covalently immobilized indium(III) composite (In/SiO2) as highly efficient reusable catalyst for A3-coupling of aldehydes, alkynes and amines under solvent-free conditions

We describe the synthesis and application of a silica-xerogel-supported indium(III) composite (In/SiO2). Using X-ray photoelectron spectroscopy, by the first time it was possible to identify that the indium is bonded to the silica through covalent InOSi bonds. The N2 adsorption/desorption isotherms revealed that the In/SiO2 composite presents pores with diameters between 1 and 4nm, which allows it to be used as a heterogeneous catalyst. Thus, this composite was used as catalyst in an A3-coupling reaction with several aldehydes, amines and acetylenes, leading to the formation of propargylamines in good-to-excellent yields in solvent-free conditions, using both conventional heating and microwave irradiation (MW). The recyclability was evaluated under both conditions and no considerable reduction in the yields was observed after four cycles.

Gold immobilized onto poly(ionic liquid) functionalized magnetic nanoparticles: a robust magnetically recoverable catalyst for the synthesis of propargylamine in water

Supported gold(iii) on poly(ionic liquid) coated on magnetic nanoparticles produced a highly active, stable, recoverable and high loading for the synthesis of propargylamines (A3 coupling reaction) under green conditions.

Lanthanum loaded CuO nanoparticles: synthesis and characterization of a recyclable catalyst for the synthesis of 1,4-disubstituted 1,2,3-triazoles and propargylamines

A click and three component A3coupling reactions were achieved by lanthanum loaded CuO NPs under ultrasonication. 1,4-Disubstituted 1,2,3-triazoles and propargylamines were synthesized in a short reaction time with high regioselectivity and yields.

Aldehyde–alkyne–amine (A3) coupling catalyzed by a highly efficient dicopper complex

A dicopper(i) complex was developed as highly efficient catalyst for A3 coupling reactions, which led to the formation of propargylamines.

Excellent catalytic activity of magnetically recoverable Fe3O4–graphene oxide nanocomposites prepared by a simple method

An Fe3O4-graphene oxide nanocomposite has been synthesized via a chemical reaction with a magnetite particle size of 18-25 nm. The resulting nanocomposite can be easily manipulated by an external magnetic field, exhibits excellent catalytic activity and may be reused for several cycles with marginal loss of activity. This recyclable nanocomposite provides an efficient, economic, novel route for multi-component A(3) coupling reactions of aldehydes, amines and alkynes and gives the propargylamine in excellent yields.