Copper-catalyzed azide-alkyne cycloaddition reaction in water using cyclodextrin as a phase transfer catalyst

1,4-Disubstituted-1,2,3-triazoles were obtained in excellent yields from azides and terminal alkynes in H(2)O in the presence of catalytic amount of β-cyclodextrin as a phase transfer catalyst. Also, a one-pot CuAAC reaction was carried out successfully, affording 1,4-disubstituted-1,2,3-triazoles in good to high yields starting from an alkyl bromide, sodium azide, and terminal alkyne.     

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.     

Oxidation of 1,4-disubstituted-1,2,3-triazoles with H2O2–CF3CO2H: efficient synthesis of 1,2,3-triazole 3-oxides

A collection of 1,2,3-triazole-3-oxides was obtained from oxidation of the corresponding 1,4-disubstituted-1,2,3-triazoles mediated by a H₂O₂–CF₃CO₂H system through a simple protocol in good yields showing high efficiency.     

Click synthesis of 1,4-disubstituted-1,2,3-triazoles catalyzed by melamine-supported CuO nanoparticles as an efficient recyclable catalyst in water

Melamine-supported CuO nanoparticles (M-CuO nanocatalyst) are prepared as a new and efficient recyclable nanocatalyst for the regioselective synthesis of 1,2,3-triazoles in water. This new nanocatalyst was prepared by co-precipitation method and characterized by FT-IR spectral study, TGA, DSC, XRF, ICP-OES, XRD, SEM, EDS and BET analysis. A wide range of 1,4-disubstituted-1,2,3-triazoles were synthesized from reaction of benzyl halides or alkyl halides with phenyl acetylene and sodium azide in high yields. M-CuO nanocatalyst could be reused more than 6 times without considerable loss of its initial activity.

     

Nano-copper catalyzed three-component reaction to construct 1,4-substituted 1,2,3-triazoles

Three-component reaction of alkyl halides, sodium azide with terminal alkynes can be catalyzed by nano-copper particles under ambient conditions. A series of 1,4-disubstituted-1,2,3-triazoles were obtained regioselectively by this one-pot strategy. Nano copper can be reused at least three times without significant deactivation.     

Synthesis of 6-amino-5-cyano-1,4-disubstituted-2(1H)-pyrimidinones via copper-(I)-catalyzed alkyne-azide 'click chemistry' and their reactivity

In this paper we present the room temperature synthesis of a novel serie of 1,4-disubstituted-1,2,3-triazoles 4a-l by employing the (3+2) cycloaddition reaction of pyrimidinones containing alkyne functions with different model azides in the presence of copper sulphate and sodium ascorbate. To obtain the final triazoles, we also synthesized the major precursors 6-amino-5-cyano-1,4-disubstituted-2(1H)-pyrimidinones 3a-r from ethyl 2,2-dicyanovinylcarbamate derivatives 2a-c and various primary aromatic amines containing an alkyne group. The triazoles were prepared in good to very good yields.     

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.     

A recyclable/reusable hydrotalcite supported copper nano catalyst for 1,4-disubstituted-1,2,3-triazole synthesis via click chemistry approach

Using hydrotalcite as solid support, copper nano particles were synthesized and used in azide-alkyne cycloaddition reaction en route to the synthesis of 1,4-disubstituted-1,2,3-triazoles. The catalyst is heterogeneous and can be recycled and reused easily. Room temperature reaction condition and the use of ethylene glycol as solvent make it an environment friendly system.     

A microwave-assisted click chemistry synthesis of 1,4-disubstituted 1,2,3-triazoles via a copper(I)-catalyzed three-component reaction

A microwave-assisted three-component reaction was used to prepare a series of 1,4-disubstituted-1,2,3-triazoles from corresponding alkyl halides, sodium azide, and alkynes. This procedure eliminates the need to handle organic azides, as they are generated in situ, making this already powerful click process even more user-friendly and safe.     

Synthesis of azide-alkyne fragments for ‘click’ chemical applications; formation of oligomers from orthogonally protected trialkylsilyl-propargyl azides and propargyl alcohols

A series of orthogonally protected 1,4-disubstituted-1,2,3-triazoles were prepared from the corresponding alkynols and trialkylsilyl-propargyl azides via 1,3-dipolar cycloaddition. These cycloadducts were selectively deprotected and extended in a stepwise fashion via further ‘click’ reactions to form oligomeric peptidomimetic compounds. This methodology gives access to triazole-based peptidomimetics in a controlled fashion and lays the foundation for a fragment-based approach to drug discovery.     

Copper iodide nanoparticles on poly(4-vinyl pyridine) as new and green catalyst for multicomponent click synthesis of 1,4-disubstituted-l,2,3-triazoles in water

Poly(4-vinyl pyridine) supported nanoparticle of copper(Ⅰ) iodide is reported as a green and recyclable catalyst for the regioselective synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from benzyl halides,sodium azide and terminal alkynes in water. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any loss of its efficiency.     

A ditopic calix[6]arene ligand with N-methylimidazole and 1,2,3-triazole substituents: synthesis and coordination with Zn(II) cations

The first member of a new class of ditopic calix[6]arene has been synthesized, which is decorated with three N-methylimidazoles at the small rim and three 1,4-disubstituted-1,2,3-triazoles at the large rim. The coordination of a first Zn(II) cation selectively takes place at the small rim. Addition of a second equivalent results in the complexation of the three triazoles, providing a rare example of 1,2,3-triazole ligands embedded within a supramolecular system.     

Synthesis of 5-Iodo-1,4-disubstituted-1,2,3-triazoles Mediated by in Situ Generated Copper(I) Catalyst and Electrophilic Triiodide Ion

Mixing copper(II) perchlorate and sodium iodide solutions results in copper(I) species and the electrophilic triiodide ions, which collectively mediate the cycloaddition reaction of organic azide and terminal alkyne to afford 5-iodo-1,4-disubstituted-1,2,3-triazoles. One molar equivalent of an amine additive is required for achieving a full conversion. Excessive addition of the amine compromises the selectivity for 5-iodo-1,2,3-triazole by promoting the formation of 5-proto-1,2,3-triazole. Based on preliminary kinetic and structural evidence, a mechanistic model is formulated in which a 5-iodo-1,2,3-triazole is formed via iodination of a copper(I) triazolide intermediate by the electrophilic triiodide ions (and possibly triethyliodoammonium ions). The experimental evidence explains the higher reactivity of the in situ generated copper(I) species and triiodide ion in the formation of 5-iodo-1,2,3-triazoles than that of the pure forms of copper(I) iodide and iodine.     

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.     

Synthesis of a polyprenyl-type library containing 1,4-disubstituted-1,2,3-triazoles with anti-biofilm activities against Pseudoalteromonas sp.

A terpenoid-like library containing 1,4-disubstituted-(1H)-1,2,3-triazoles was prepared by means of 1,3-dipolar cycloaddition of geranyl and farnesyl azides with a set of terminal alkynes, in order to design a new class of potentially active anti-biofilm compounds. Reactions were optimized to proceed under mild conditions and in high yields. Two compounds were found to possess interesting activity against Pseudoalteromonas sp. biofilm. This process is suitable for combinatorial chemistry of marine natural product-like compounds.     

Synthesis of 5-alkynyl-2,2,6-trimethyl-1,3-dioxin-4-ones and 1,4-disubstituted-1,2,3-triazoles

Herein we report an approach to the formation of 5-alkynyl-1,3-dioxin-4-ones using Suzuki-Miyaura cross-coupling reaction of potassium alkynyltrifluoroborate salts with 2,2,6-trimethyl-5-iodo-1,3-dioxin-4-one. The resulting 5-ethynyltrimethylsilyl-1,3-dioxin-4-ones obtained through the Sonogashira reaction were further reacted in a Cu(I)-catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition to form functionalized 1,4-disubstituted-1,2,3-triazoles in good yields, using mild conditions and ultrasonic radiation to expedite the reaction.     

Direct synthesis of 1,5-disubstituted-4-magnesio-1,2,3-triazoles, revisited

After revisiting earlier works reporting the regioselective synthesis of 1,5-disubstituted-1,2,3-triazoles via the addition of bromomagnesium acetylides to azides, much improved yields of the products were obtained for a wide array of azides and alkynes. The intermediates of that reaction can be trapped with different electrophiles to regioselectively form 1,4,5-trisubstituted 1,2,3-triazoles. [reaction: see text]     

A facile and regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles using click chemistry

The reaction of α-tosyloxy ketones, sodium azide, and terminal alkynes in presence of copper(I) in aqueous polyethylene glycol afforded regioselectively 1,4-disubstituted 1,2,3-triazoles in good yield at ambient temperature. The one-pot exclusive formation of 1,4-disubstituted 1,2,3-triazoles involves in situ formation of α-azido ketones, followed by cycloaddition reaction with terminal alkyne. The generality of this one-pot method was demonstrated by synthesizing an array of diverse 1,4-disubstituted 1,2,3-triazoles.     

One step cascade synthesis of 4,5-disubstituted-1,2,3-(NH)-triazoles

A Lewis base-catalyzed three-component cascade reaction was developed for the synthesis of 4,5-disubstituted-1,2,3-(NH)-triazoles. More than 25 new (NH)-triazoles were prepared in good to excellent yields under mild conditions. The availability of the C-4 vinyl group allows easy conversion into other triazole derivatives.     

Convenient and efficient Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions catalyzed by 1,3,4-trisubstituted-1,2,3-triazolium iodide and palladium salt systems

A series of 1,3,4-trisubstituted-1,2,3-triazolium iodide salts (4a–c) were synthesized via a three-step reaction sequence. Corresponding anilines (1a–c) were converted to azides (2a–c) which were then treated with phenylacetylene with “Click” chemistry to access 1,4-disubstituted-1,2,3-triazoles (3a–c). Subsequent methylation of 1,4-disubstituted-1,2,3-triazoles (3a–c) yielded 1,3,4-trisubstituted-1,2,3-triazoliumiodide salts (4a–c) in appreciable yields. All the synthesized compounds were characterized by ¹H and ¹³C NMR, ATR–IR spectroscopic techniques and elemental analyses. Additionally, the structure of 1-(4-chlorophenyl)-4-phenyl-1,2,3-triazole (3b) was confirmed by single crystal X-ray diffraction analysis. The catalytic activity of 4a–c in a catalytic system consisting of 1,3,4-trisubstituted-1,2,3-triazoliumiodide salt/palladium(II) acetate/base were investigated toward Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions. The Suzuki–Miyaura cross-coupling reactions were carried out under mild reaction conditions with good to excellent yields, whereas Heck–Mizoroki cross-coupling reactions were performed at elevated temperature with moderate yields. Further, in situ method skips the synthetic procedure of preparing the palladium(II) complexes and hence is more economical and less tedious.