Cu(I)-catalyzed one-pot synthesis of 1,4-disubstituted 1,2,3-triazoles via nucleophilic displacement and 1,3-dipolar cycloaddition

An efficient method is described for the regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles in high yields from a variety of Baylis-Hillman acetates and terminal alkynes with sodium azide using CuI as a catalyst, in either water or polyethylene glycol (PEG). This procedure is operationally simple and environmentally benign. Polyethylene glycol (PEG) serves as an efficient reusable solvent with higher efficiency.     

Novel synthesis of 5-iodo-1,2,3-triazoles using an aqueous iodination system under air

A novel aqueous iodination system was developed for the synthesis of 5-iodo-1,2,3-triazoles under air. This reaction system has high efficiency and excellent chemo-selectivity with wide functional group tolerance. In addition, this method can be utilized for the modification of biomolecules such as riboses and nucleosides, and for the double labeling of biomolecules when coupled with other reaction types such as the Sonogashira reaction.     

Design and Synthesis of New 5-aryl-4-Arylethynyl-1H-1,2,3-triazoles with Valuable Photophysical and Biological Properties

Cu-catalyzed 1,3-dipolar cycloaddition of methyl 2-azidoacetate to iodobuta-1,3-diynes and subsequent Suzuki-Miyaura cross-coupling were used to synthesize new triazoles derivatives: 5-aryl-4-arylethynyl-1H-1,2,3-triazoles. Investigation of their optical properties by using UV absorption and fluorescence emission spectroscopies revealed that all molecules possess fluorescence properties with the values of the Stokes shift more than 100 nm. The photophysical behavior of the two most promising triazoles in polar and non-polar solvents was also studied.     

On the lead tetraacetate oxidation of 4-amino-1,2,4-triazoles, 1-amino- and 2-amino-1,2,3-triazoles

Lead tetraacetate oxidation of 4-amino-1,2,4-triazoles, 1-amino- and 2-amino-1,2,3-triazoles affords mainly fragmentation to nitriles or acetylenes, even in the presence of intramolecularly attached double bonds.

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Über die Bleitetraacetatoxidation von 4-Amino-1,2,4-triazolen, 1-Amino- und 2-Amino-1,2,3-triazolen (Kurze Mitteilung)

Zusammenfassung Bei der Oxidation von 4-Amino-1,2,4-triazolen, 1-Amino- und 2-Amino-1,2,3-triazolen mit Bleitetraacetat entstanden hauptsächlich Nitrile bzw. Acetylene durch Fragmentierung — trotz der Gegenwart von intramolekularen Doppelbindungen.

     

Click chemistry approach for the regioselective synthesis of iso-indoline-1,3-dione-linked 1,4 and 1,5 coumarinyl 1,2,3-triazoles and their photophysical properties

Copper-catalyzed reaction of N-propargyl isoindoline-1,3-dione and 4-azidomethyl coumarins / 4-azidomethyl-1-aza coumarins under click chemistry conditions afforded 1,4-disubstituted 1,2,3-triazoles, whereas ruthenium catalysis yielded isomeric 1,5-disubstituted 1,2,3-triazoles. The two regioisomers have been distinguished by NOE studies. UV absorption for a given pair of isomers exhibited similar trend, whereas fluorescence measurements showed considerable differences. Photo physical studies on the interaction of azides with copper and ruthenium have also been performed.     

6-Aryl-2,2-dimethyl-1,3-dioxin-4-ones: Synthesis and Chemical Characteristics. (Review)

Methods for the production of 6-aryl-2,2-dimethyl-1,3-dioxin-4-ones and their thermolysis in the presence of nucleophiles and dienophiles are discussed     

4-芳亚甲基-4,5-二氢-1,3-二苯基吡唑-5-酮的一锅法合成

报道了以乙酸为催化剂,由苯甲酰乙酸乙酯、苯肼和芳香醛经三组分一锅法缩合制备4-芳亚甲基-4,5-二氢-1,3-二苯基吡唑-5-酮衍生物的新方法.该方法缩短了反应时间,得到了中等产率.产物结构经MS,1HNMR,IR和元素分析确证.     

Synthesis of new 1-substituted 4-perfluoroalkyl tetrazol-5-ones

1,3-Dipolar cycloaddition of perfluoroalkyl ethyle azides 1 with isocyanates 2 afforded 1-perfluoroalkyl-4-(n-Bu, phenyl or mesitylsulfonyl) tetrazol-5-ones 3 in good yields. The use of perfluoroalkyl ethyl azides extends the reaction to the less reactive n-butyl isocyanate.     

Facile synthesis,characterization, and antimicrobial studies of some disubstituted 1,2,3-triazoles with sulfonamide functionality

An expedient synthesis of some 1,4-disubstituted 1,2,3-triazoles (3a–3x) having sulfonamide functionality from various terminal alkynes and aromatic azides through Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition has been reported. The structures of newly synthesized compounds were confirmed by IR, ¹H NMR, ¹³C NMR, high-resolution mass spectra and screened for in vitro antimicrobial activity against Staphylococcus aureus (Gram-positive bacteria), Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes (Gram-negative bacteria), Candida albicans, and Aspergillus niger (fungi). Some of the synthesized compounds were found to exhibit good potency against above-tested microbial strains. Moreover, to study the binding interactions, docking simulation of broadly active compound 3x was also performed against E. coli dihydropteroate synthase enzyme.     

Synthesis and properties of nitro-1,2,3-triazoles (Review)

Published data on methods for the synthesis of substituted 4(5)-nitro-1,2,3-triazoles and their properties are reviewed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 3–25, January, 2008.     

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.     

Quantum-chemical investigation of certain physicochemical properties of C-nitro-1,2,3-triazole and N-alkyl-4(5)-nitro-1,2,3-triazoles

Quantum-chemical calculations have been carried out on molecular electrostatic potentials, proton affinity in the gas phase, gas phase basicity, and pK _BH+ values in aqueous solution for C-nitro- and N-alkyl-4(5)-nitro-1,2,3-triazoles, and the relative stability of the isomeric N-alkyl-4(5)-nitrotriazoles (alkyl = Me, Et, i-Pr, t-Bu) in the gas phase and in aqueous solution. For all the studied substances in the gas phase the 2H-tautomer and the N(2)-isomers were considerably more stable than the corresponding N(1) compounds, and the 3H-tautomer and N(3)-isomer were the least stable. In aqueous solution 1- and 3-isomers had close values of energies, but in the case of C-nitro-1,2,3-triazole the 1H form became even more stable than the 2H-form. It was established which ring nitrogen atoms of 1,2,3-triazoles are protonated in the gas phase and in solution. The obtained data correlate well with the results of experimental investigations on the alkylation of 1,2,3-triazoles in acidic and basic media and of the experimental investigation on the alkylation of C-nitro-1,2,3-triazoles with diethyl sulfate carried out in the present work. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1816–1828, December, 2008.     

A novel class of 1,4-disubstituted 1,2,3-triazoles: Regioselective synthesis,antimicrobial activity and molecular docking studies

A Novel class of 1,4-disubstituted 1,2,3-triazoles have been synthesized in good to excellent yields via Cu(I) accelerated azide-alkyne click chemistry reaction strategy. The newly synthesized compounds were assessed for their in vitro antimicrobial activity against five Gram-positive, seven Gram-negative bacteria and three fungi. Most of the synthesized compounds displayed significant activity against the tested Gram-positive and Gram-negative bacteria. Molecular docking study revealed that all docked compounds are bound efficiently with the active site of Topoisomerase IV (4EMV) receptor with the observed the free energy of binding from −7.79 to −9.44 kcal/mol. Interestingly, compound 13a forms four hydrogen bonds and displayed high binding energy (−9.44 kcal/mol) with the Topoisomerase IV (4EMV) receptor which correlated with their in vitro antimicrobial assays.     

Synthesis of 1,4-diazepin-5-ones under microwave irradiation and their reduction products

A new efficient access to 1,4-diazepane derivatives is described via a microwave assisted synthesis of 7-substituted-1,4-diazepin-5-ones, which proceeds rapidly in good yields. Catalytic reduction gave 1,4-diazepan-5-ones and 1,4-diazepanes whereas a ring opening was observed by hydride reduction when a phenyl group occupies the N-benzylic position.     

Sulfated tungstate a heterogeneous acid catalyst for synthesis of 4-aryl-NH-1,2,3-triazoles by 1,3-dipolar cycloaddition of nitroolefins with NaN3

A facile and new method for the synthesis of 4-aryl-NH-1,2,3-triazoles from nitroolefins and NaN₃ by 1,3-dipolar cycloaddition reaction, employing a mild solid inorganic acid sulfated tungstate as a heterogeneous catalyst, has been developed. The protocol emphasizes broad substrate scope with many functionalities, less reaction time, stability to open air, easy work-up, and with good to excellent yields.     

Arylhydrazononitriles as precursors to 2-substituted 1,2,3-triazoles and 4-amino-5-cyano-pyrazole derivatives utilizing microwave and ultrasound irradiation

Abstract

Cyanoacetamides 3a–d were prepared by reacting ethyl cyanoacetate with primary aliphatic amines 2a–d. The formed cyanoacetamides 3a–d were coupled with aromatic diazonium salts to give the corresponding arylhydrazones 4a–i which were used as precursors to title triazoles and pyrazoles by reacting with hydroxylamine and chloroacetonitrile. Yields of products formed by conventional heating are compared with those of microwave and ultrasound irradiation     

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.     

Efficient One-Pot,Four-Component Synthesis of 1,2,3-Triazole-Linked Tetrahydrobenzo[b]pyrans

A one-pot procedure has been developed for the synthesis of (1,2,3-triazolyl) methoxyphenyl tetrahydro-5-oxo-4H-chromene derivatives by concurrent reaction of aryloxy propargylated aldehydes, various azides, active methylene compounds, and 1,3-cyclohexanediones using catalytic amounts of Cu(OAc)₂ / sodium ascorbate and diammonium hydrogen phosphate in aqueous ethanol media. Excellent conversion of starting materials was achieved to the desired (1,2,3-triazolyl) methoxyphenyl tetrahydro-5-oxo-4H-chromene products.     

Regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles via three-component coupling of secondary alcohols, TMSN3 and alkynes

1,4-Disubstituted 1,2,3-triazoles are obtained in excellent yields via a three-component coupling of secondary alcohols, alkynes and trimethylsilyl azide (TMSN₃). This one-pot reaction occurs through in situ generation of an azide from the alcohol and TMSN₃, followed by 1,3-dipolar cycloaddition of the terminal alkyne to afford the corresponding disubstituted triazoles.