Synthesis of novel 1,4-disubstituted 1,2,3-triazoles bearing organosilicon-sulfur groups via the click reaction sonocatalyzed by LaCuxMn1-xO3 nanoparticles

A highly efficient and environmentally friendly one-pot procedure for the synthesis of 1,2,3-triazoles by 1,3-dipolar cycloaddition of benzyl halides, terminal alkynes, and sodium azide over LaCu_xMn_1-xO₃ perovskite oxides was developed. LaCu_0.7Mn_0.3O₃ was found to be active with low catalyst loading under ultrasonic irradiation in aqueous media. The reaction was performed efficiently in the presence of the nanocatalyst in the absence of any additive or base with a noticeable reduction in the reaction time. The catalyst could be recycled and reused at least five times without any significant effect on the results of the reaction. Moreover, a series of novel organosilicon-sulfur substituted 1,2,3-triazole derivatives was synthesized using carbon disulfide and tris(trimethylsilyl)methylithium.     

An easy access to unsymmetrically substituted 4,4′-bi-1,2,3-triazoles

A convenient synthesis of 4-alkynyl-1,2,3-triazoles and novel unsymmetrically substituted 4,4′-bi-1,2,3-triazole derivatives has been devised starting from easily available 1-trimethylsilyl-1,3-butadiyne. The starting compound was reacted with several azides, leading to 4-(silylalkynyl)-1,2,3-triazoles, which were easily transformed into 4-arylalkynyl-1,2,3-triazoles by a Pd catalyzed coupling reaction with aryl halides, or into novel 4,4′-bi-1,2,3-triazole derivatives by a subsequent cyclization reaction with azides.     

Pd-catalyzed regioselective C-H chlorination of disubstituted 1,2,3-triazoles

This paper mainly studied Pd-catalyzed regioselective chlorination of disubstituted 1,2,3-triazoles directed by the 1,2,3-triazole ring. A series of regioselective chlorinated products were synthesized in 47–86% yields using Pd(OAc)₂ as a catalyst and CuCl₂ as a chlorinated reagent. This method provides a new mean for the synthesis of 1,2,3-triazole halides which combines the formation of C-X bond with C-H activation.     

First Synthesis of Some New 1-Aryl-4-ethoxycarbonyl- 5-dimethylaminomethyleneamino-1,2,- 3-triazole Under Vilsmeier Conditions

Abstract

Some new 1 - aryl - 4 - ethoxycarbonyl - 5 - dimethylaminomethyleneamino-1,2,3-triazoles were first prepared from 1-aryl-4-ethoxycarbonyl-5-amino-1,2,3-triazoles and N,N-dimethylformamide in the presence of phosphorus oxychloride under mild condition in excellent yields. Their structures were characterized by IR, ¹H NMR, MS, and elemental analysis, and their inhibiting effects on various bacteria were also screened.     

One-pot three-component synthesis of 1,4-disubstituted 1H-1,2,3-triazoles using green and recyclable cross-linked poly(4-vinylpyridine)-supported copper sulfate/sodium ascorbate in water/t-BuOH system

Cross-linked poly(4-vinylpyridine)-supported copper sulfate, [P₄-VP]CuSO4 as a green and recyclable, heterogeneous catalyst in the presence of sodium ascorbate (NaAsc), is reported for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles from benzyl halides, sodium azide and terminal alkyne in water/t-BuOH (1/1:V/V) at 70 °C. Various alkyl halides and benzyl halides, with electron-withdrawing groups as well as electron-donating groups, were used for synthesis of various 1,4-disubstituted-1,2,3-triazoles in high yields. The present procedure offers as short reaction time and simple reaction work up. This catalyst can be recovered by simple filtration and recycled several consecutive runs without any loss of its efficiency.     

Applications of solid supported azide anion: a one-pot, two-step preparation of functionalized 1,2,3-triazoles

Functionalized 1,2,3-triazoles were prepared in a one-pot, two-step synthesis from alkyl halides and alkynes using a polymer supported azide. Two different base resins were examined. The chemistry is suitable for the preparation of combinatorial libraries.     

Solid-phase synthesis of 1,2,3-triazoles via 1,3-dipolar cycloaddition

The solid-phase synthesis of 1,2,3-triazoles via 1,3-dipolar cycloaddition of polymer-bound azides to various alkynes is reported. Polymer-bound azides were synthesized from polymer-bound halides and sodium azide and reacted with alkynes to produce polymer-bound 1,2,3-triazoles. Cleavage of the triazoles was performed with trifluoroacetic acid. A traceless synthesis of 1,2,3-triazoles was developed using 2-methoxy-substituted resin (polymer-bound 4-hydroxy-2-methoxybenzyl alcohol). In addition, a synthesis of 4-hydroxybenzyl-substituted 1,2,3-triazoles from the bromo-Wang resin (4-(bromomethyl)phenoxymethyl polystyrene) was achieved.     

One-pot synthesis of 1,2,3-triazoles from boronic acids in water using Cu(II)-β-cyclodextrin complex as a nanocatalyst

We report here the one-pot synthesis of 1,2,3-triazoles of arylboronic acids in water. An efficient method has been developed for the synthesis of 1,2,3-triazoles via a one-pot reaction of an arylboronic acid with sodium azide in the presence of Cu(2)-β-CD (CD = Cyclodextrin) as a nanocatalyst in water followed by a click cyclization reaction with an alkyne at room temperature in air without any additives. This method is simple, rapid, and high yielding.     

CuI-Catalyzed,One-Pot,Three-Component Huisgen Cycloaddition Reaction of Conjugated Enynes and In Situ–Generated Azides

A novel and efficient copper(I)-catalyzed three-component Huisgen cycloaddition reaction of conjugated enynes, alkyl halides, and sodium azide has been developed. These reactions were performed in the absence of amide ligands at room temperature, and the corresponding mono- and bis-1,2,3-triazoles were obtained in good to excellent yields in a one-pot procedure.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

One-pot synthesis of 4,5-disubstituted 1,2,3-(NH)-triazoles using terminal acetylenes, carbon monoxide, aryl iodides, and sodium azide

A one-pot method for the synthesis of 4,5-disubstituted-1,2,3-(NH)-triazoles via carbonylative Sonogashira reaction/1,3-dipolar cycloaddition of terminal acetylenes, carbon monoxide, aryl iodides, and sodium azide was developed. A series of new 4,5-disubstituted-1,2,3-(NH)-triazoles were prepared readily under mild conditions.     

1,2,3-Triazole N(2)-chelated C–S coupling: Access to ortho methylthiolated 1,2,3-triazoles

CuF₂-mediated selective C-S coupling of 1,4-disubstituted 1,2,3-triazole halides using the widely available DMSO as the methylthiolation reagent were achieved through the chelation of N(2) atom in triazole ring. The ortho- C-halogen bond in N(1) aryl was selectively coupled, while other C-halogen bonds remained, generating 1,4- disubstituted 1,2,3-triazoles bearing aryl methyl thioether fragment.     

Efficient synthesis of 1,4-disubstituted 1,2,3-triazoles in ionic liquid/water system

A copper(I) catalyst in a mixture of the ionic liquid [bmim][BF₄] and water, can effect three-component reaction of halides, sodium azide and alkynes to form 1,4-disubstituted 1,2,3-triazoles in good to high yields. The method is efficient and environmentally friendly.     

Synthesis of 2(5H)-Furanone Derivatives with Symmetrical and Unsymmetrical Bis-1,2,3-triazole Structure

The interesting bioactivities of 2(5H)-furanone, 1,2,3-triazole, and amino acid derivatives have promoted their combination into one multifunctional molecule. The symmetrical bis-1,2,3-triazoles and mono-1,2,3-triazoles with one free azide group are synthesized respectively by controlling the molar ratio of reactants, N-[5-alkoxy-2(5H)-furanonyl] amino acid propargyl ester and 1,4-diazidobutane. The unsymmetrical bis-1,2,3-triazoles are afforded by the subsequent reaction of mono-1,2,3-triazoles with other terminal alkynes with good to excellent yields in a short time under the same mild “click” reaction conditions. The 32 new compounds obtained in the reactions are characterized by Fourier transform infrared, ¹H NMR, ¹³C NMR, mass spectrometry, and elemental analysis. Because of the diversity of four or five basic units in molecule, this methodology provides easy access to different chiral 2(5H)-furanone compounds with polyheterocyclic structure, especially with unsymmetrical bis-1,2,3-triazole moiety. Importantly, a simple approach is provided for the synthesis of unsymmetrical bis-1,2,3-triazoles using common diazides.     

Design of a palladium nanocatalyst produced from Schiff base modified dialdehyde cellulose and its application in aryl halide cyanation and reduction of nitroarenes

In this paper, a versatile heterogeneous catalyst system (Pd-DAC-Sch) based on stabilization of palladium nanoparticles on dialdehyde cellulose Schiff base (DAC-Sch) was developed and characterized thoroughly by a variety of spectroscopic (FT-IR, XRD, ¹³C CPMAS, and TG) and microscopic (SEM/EDS and TEM) methods. Then the prepared Pd-DAC-Sch system was evaluated as a heterogeneous nanocatalyst for aryl halide cyanation in the presence of K₄[Fe(CN)₆] and for reduction of nitroarenes to amines using NaBH₄ in water at room temperature. Pd-DAC-Sch nanocatalyst efficiently cyanated various aryl halides by providing satisfactory reaction yields of 87–98%. Moreover, Pd-DAC-Sch catalyzed 4-nitrophenole (4-NA), 2-nitroaniline (2-NA), and 4-nitroaniline (4-NA) reductions in short reaction time. More importantly, Pd-DAC-Sch nanocatalyst was reapplied up to six successive runs by giving a yield of 86% without any important changes in its morphology and structure. This paper shows that Pd-DAC-Sch is a highly effective, reusable, chemically stable, and therefore a useful nanocatalyst.

     

One-pot synthesis of 1,4-disubstituted 1,2,3-triazoles from in situ generated azides

[reaction: see text] 1,4-Disubstituted 1,2,3-triazoles are obtained in excellent yields by a convenient one-pot procedure from a variety of readily available aromatic and aliphatic halides without isolation of potentially unstable organic azide intermediates.     

One-pot three-step synthesis of 1,2,3-triazoles by copper-catalyzed cycloaddition of azides with alkynes formed by a Sonogashira cross-coupling and desilylation

A microwave-assisted, one-pot, three-step Sonogashira cross-coupling-desilylation-cycloaddition sequence was developed for the convenient preparation of 1,4-disubstituted 1,2,3-triazoles starting from a range of halides, acyl chlorides, ethynyltrimethylsilane, and azides.     

Practical one-pot synthesis of 5-alkynyl-1,2,3-triazoles via heterogeneous copper(I)-catalyzed tandem three-component click/alkynylation reaction

An efficient and practical route to 5-alkynyl-1,2,3-triazoles has been developed via heterogeneous tandem CuAAC/alkynylation reaction of organic azides, alkynes and 1-bromoalkynes by using an L-proline-functionalized MCM-41-anchored copper(I) complex [L-Proline-MCM-41-CuCl] as catalyst under mild conditions. The reaction produces a wide variety of 5-alkynyl-1,2,3-triazoles in mostly good to excellent yields. The new immobilized copper(I) complex can be readily prepared from commercially available and inexpensive reagents and displays the same catalytic activity as CuCl. The L-Proline-MCM-41-CuCl catalyst is also easy to recover via a simple filtration process and can be reused at least seven times without apparent loss of activity.     

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

Abstract

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.     

Copper immobilized on biomimetic assembled calcium carbonate/carboxymethylcellulose hybrid: a highly active recoverable catalyst for CuAAC reactions

A novel copper immobilized on biomimetic assembled carboxymethylcellulose/calcium carbonate hybrid (Cu^II@CMC/CaCO₃) as an efficient heterogeneous catalyst for the synthesis of 1,2,3-triazoles has been described herein. The fabrication of Cu^II@CMC/CaCO₃ is accomplished through a bioinspired mineralization process using sodium carboxymethylcellulose (CMC-Na) as the template and ion exchange agent, while the metathesis, nucleation, assemble, hybridization, and immobilization of Cu(II) occurred by successful treatment with CaCl₂, Na₂CO₃, and CuSO₄ in water at room temperature. The resultant Cu^II@CMC/CaCO₃ hybrid was well characterized by various analyses such as FT-IR, XRD, SEM, EDX, EDX-mapping, TEM, and TGA techniques. In the presence of low copper loading of Cu^II@CMC/CaCO₃ hybrid, benzylic halides, azide, and alkynes proceeded smoothly to afford 1,4-disubstituted 1,2,3-triazoles in high yields. The catalyst can be conveniently recovered from the reaction mixture by filter and reused for at least 5 consecutive runs with a slight drop in its catalytic activity. The remarkable activity and stability of the catalyst may be attributed to the coordination of both carboxyl and hydroxyl groups of the hybrid of CMC/CaCO₃.