Synthesis of 1,2,3-triazole nucleosides via the acid-catalyzed fusion procedure

The acid-catalyzed fusion of methyl 1,2,3-triazole-4-carboxylate, 4-cyano-1,2,3-triazole, and 4-nitro-1,2,3-triazole with an acylated ribofuranose provided the corresponding 2-β-D-ribo-furanosyl-4-substituted-1,2,3-triazoles along with the isomeric 1-β-D-ribofuranosyl-4-substituted-1,2,3-triazoles. The structures of these nucleosides were assigned on the basis of their nmr spectra. The synthesis of 2-β-D-ribofuranosyl-1,2,3-triazole-4-carboxamide from both the corresponding methyl ester and cyano nucleosides is described. The cyano nucleosides were utilized to prepare 2-β-D-ribofuranosyl-1,2,3-triazole-4-thiocarboxa?ide and 1-β-D-ribofuranosyl-1,2,3-triazole-4-thiocarboxamide. Reduction of the 4-nitro-1,2,3-triazole nucleosides provided 4-amino-2-β-D-ribofuranosyl-1,2,3-triazole and the isomeric 4-amino-1-β-D-ribofuranosyl-1,2,3-triazole. The acid-catalyzed fusion procedure with 1,2,3-triazole afforded 1-β-D-ribofuranosyl-1,2,3-triazole and 2-β-D-ribofuranosyl-1,2,3-triazole.     

Synthesis of 5-functionalized-1,2,3-triazoles via a one-pot aerobic oxidative coupling reaction of alkynes and azicles

In this paper, an efficient synthesis of 5-alkynyl-1,2,3-triazoles through a one-pot aerobic oxidative coupling reaction of various alkynes and azides has been developed. Further derivatization of 5-alkynyl-1,2,3-triazoles readily yielded 5-carbonyl-1,2,3-triazoles, 5-carboxylic-1,2,3-triazole, 5-hydroxyalkyl-1,2,3-triazoles and 5-quinoxaline-1,2,3-triazole, which provided an entry into structurally diverse 5-functionalized-1,2,3-triazoles.     

Synthesis of 5-functionalized-1,2,3-triazoles via a one-pot aerobic oxidative coupling reaction of alkynes and azides

In this paper, an efficient synthesis of 5-alkynyl-1,2,3-triazoles through a one-pot aerobic oxidative coupling reaction of various alkynes and azides has been developed. Further derivatization of 5-alkynyl-1,2,3-triazoles readily yielded 5-carbonyl-1,2,3-triazoles, 5-carboxylic-1,2,3-triazole, 5-hydroxyalkyl-1,2,3-triazoles and 5-quinoxaline-1,2,3-triazole, which provided an entry into structurally diverse 5-functionalized-1,2,3-triazoles.     

Metal-free and azide-free synthesis of 1,2,3-triazoles derivatives

1,2,3-Triazoles, significant five-membered ring N-heterocycles, are main structural moieties in well-designed materials, pharmaceutical agents, bioactive products, and synthetic intermediates. In the research of life sciences and pharmaceuticals, by seeing the spacious applications of 1,2,3-triazoles, the progress of metal-free method is exceedingly desirable to evade the heterocyclic product metal contamination. Moreover, on a larger scale, the toxicity and explosiveness of azides makes azides discommode and hard to hold, to synthesize 1,2,3-triazoles. The need to steer the development of the synthesis of 1,2,3-triazoles toward more maintainable synthesis is a pressing issue. There are rare methods to construct 1,2,3-triazoles under azide-free and metal-free environments. These rare methods are compiled in this review. The afford of the collection and compilation of azide-free and metal-free synthesis methodologies of 1,2,3-triazole in single podium is supportive and crucial for synthetic chemist to extend the diversity of the synthesis of 1,2,3-trizoles through green protocol.     

1,2,3-三唑化合物的合成研究进展

1,2,3-三唑化合物是重要的N-杂环化合物, 近年来被广泛应用于工业生产、药物研发、材料科学等多个领域. 因此1,2,3-三唑的合成受到越来越多的关注. 从合成不同取代类型的1,2,3-三唑化合物入手对近年来研究发现的合成方法的进展进行了综述.     

Selenium heterocycles. XXXV . Synthesis and pyrrolysis of aryloxy-, arylthio-, and arylseleno-1,2,3-selenadiazoles

A series of 4-substituted-5-arylthio-1,2,3-selenadiazoles, 4-substituted-5-arylseleno-1,2,3-selenadiazoles and 4-aryloxymethyl-1,2,3-selenadiazoles were synthesized. Pyrrolysis of these compounds afforded the corresponding acetylenes XI, XIII (X = S, Se) and XII, respectively. Oxidation of 4-substituted-5-arylthio-1,2,3-selenadiazoles (XIV) with m-chloroperbenzoic acid gave 4-substituted-5-arylsulfinyl-1,2,3-selenadiazoles (XV) and 4-substituted-5-arylsulfonyl-1,2,3-selenadiazoles (XVI).     

Click-chemistry-based multicomponent condensation approach for design and synthesis of spirochromene-tethered 1,2,3-triazoles as potential antitubercular agents

Research on Chemical Intermediates - A series of spirochromene-tethered 1,2,3-triazoles (1,2,3-triazolylspirochromenes) were designed and synthesized via click-chemistry-based one-pot...     

Catalytic Conversion of 1,2,3-Trimethylbenzene Over HY Zeolite

The reaction of 1,2,3-trimethylbenzene (1,2,3-TMB) over HY zeolite was investigated in a fixed-bed flow reactor at 200-300 °C under atmospheric pressure. The reaction products include toluene, pentamethylbenzene and isomers of xylene, 1,2,3-TMB and tetramethylbenzene. Based on the time-on-stream theory, the types and initial selectivities of these products were determined from plots of product selectivity. 1,2,4-TMB is initially produced from 1,2,3-TMB via isomerization whereas o-xylene, m-xylene, 1,2,3,4- and 1,2,3,5-tetramethylbenzene were primarily formed by disproportionation of 1,2,3-TMB. Isomerization and disproportionation obeyed first- and second-order kinetics, respectively; both reactions proceeded via a carbonium ion mechanism with the former occurring by methyl transfer on the benzene ring whereas the latter proceeded through the diphenylmethane transition state. The activation energies are 31.6 and 37.2 kJ mol^?1 for isomerizaion and disproportionation, respectively.     

Materials Chemistry of 1,2,3-Selenadiazoles

Abstract

The organic chemistry of 1,2,3-selenadiazoles has been explored to a greater extent due to the fact that the chemistry of 1,2,3-selenadiazoles mostly is driven by its facile decomposition via elimination of a nitrogen molecule and formation of selenaketocarben and/or its dimerization to 1,4-diselenin. The reactions of 1,2,3-selenadiazoles directly with various transition metal compounds have resulted in unique organo-selenium transition metal complexes. However, the materials chemistry of 1,2,3-selenadiazoles has not appeared in literature prior to the first publication on the subject from our laboratory in 2003. To, the best of our knowledge, no research group is engaged in such an activity. We, have exclusively explored the potential of 1,2,3-selenadiazoles for their effective utilization in synthesis of semiconductor nano particles or nano powder and in this lecture, the results and methodology for the same would be discussed.     

Reactions of 1,2,3-Triazoles with Trifluoromethanesulfonyl Chloride and Trifluoromethanesulfonic Anhydride

Reactions of 4,5-dibromo-1,2,3-triazole, 1H-1,2,3-benzotriazole, and 2-phenyl-2H-1,2,3-triazole-4-carbonyl chloride with trifluoromethanesulfonyl chloride and trifluoromethanesulfonic anhydride were studied. 4,5-Dibromo-1,2,3-triazole sodium salt reacted with CF₃SO₂Cl in tetrahydrofuran to give 4,5-dibromo-2-(2-tetrahydrofuryl)-2H-1,2,3-triazole rather than expected 4,5-dibromo-2-trifluoromethylsulfonyl-2H-1,2,3-triazole. The latter was synthesized by treatment of 4,5-dibromo-1,2,3-triazole sodium salt with trifluoromethanesulfonic anhydride. The reaction of benzotriazole with (CF₃SO₂)₂O afforded 1-trifluoromethylsulfonyl-1H-1,2,3-benzotriazole and 1,2,3-benzotriazolium trifluoromethanesulfonate. 2-Phenyl-2H-1,2,3-triazole-4-carbonyl chloride reacted with trifluoromethanesulfonamide sodium salt in DMF, yielding N-(dimethylaminomethylene)trifluoromethanesulfonamide. Possible ways for formation of the unexpected products were proposed.     

含1,2,3-三氮唑结构的1,5-苯并硫氮杂[艹卓]的合成及其抑真菌活性

设计合成了三类含1,2,3-三氮唑结构的1,5-苯并硫氮杂[艹卓]化合物3-(1H-1,2,3-三氮唑)-4-芳基-2,5-二氢-1,5-苯并硫氮杂[艹卓](5a^5f)、3-(2H-1,2,3-三氮唑)-4-芳基-2,3-二氢-1,5-苯并硫氮杂[艹卓](6a^6f)和3-(1H-1,2,3-三氮唑)-4-芳基-2,3,4,5-四氢-1,5-苯并硫氮杂[艹卓](7a^7f).研究了中间体及目标产物的合成条件,分离出其中两个副产物并进行了结构确定.目标产物的抑真菌活性测试表明,化合物5a^5f对真菌具有良好的抑制作用,对新生隐球菌的抑制效果尤为突出.初步抑真菌构效关系研究表明, 1H-1,2,3-三氮唑环和C=C双键是化合物5a^5f抑真菌活性的关键官能团.     

Selenium heterocycles XXV. Synthesis of thieno[3,4-d][1,2,3]-thiadiazole,selenolo[3,4-d][1,2,3]thiadiazole and pyrrolo[3,4-d][1,2,3]-thiadiazole. Three novel ring systems

Starting from the readily available 4-bromomethyl-5-benzoyl-1,2,3-thiadiazole and 5-bromomethyl-4-benzoyl-1,2,3-thiadiazole; thieno[3,4-d][1,2,3]thiadiazole, selenolo[3,4-d][1,2,3]-thiadiazole and pyrrolo[3,4-d][1,2,3]thiadiazole were synthesized in good yield.     

Homocoupling of bromotriazole derivatives on metal complex catalysts

Russian Chemical Bulletin - Homocoupling of 4-bromo-1,2,3-triazoles upon treatment with stoichiometric amount of bis(pinacolato)diboron on a palladium catalyst gives 4,4´-bi-1,2,3-triazoles in...     

Surface enhanced Raman scattering investigation of the halide anion effect on the adsorption of 1,2,3-triazole on silver and gold colloidal nanoparticles

The halide anion effect on the adsorption of 1,2,3-triazole on Ag and Au colloidal nanoparticles has been investigated by means of surface enhanced Raman scattering (SERS), UV-visible absorption spectroscopy, and scanning electron microscopy. To interpret the SERS spectra, the vibrational spectra of 1,2,3-triazole were assigned with the help of density functional theoretical (DFT) calculations of the two tautomers of 1,2,3-triazole, both free and bound to Ag and Au adatoms. Upon addition of halide anions, both tautomers interact with the Ag surface through one nitrogen atom. Analogous behavior is observed in the case of basified Au colloids, whereas at the usual pH of these hydrosols (approximately 6) the adsorption of 1,2,3-triazole is the same of that observed in halide-free colloids.     

Reactions of cycloalkeno -1,2,3-selenadiazole with nucleophiles

Reactions of cycloalkeno-1,2,3-selenadiazole and various nucleophiles were studied. In the case of 5-membered ring fused 1,2,3-selenadiazole, nucleophilic attack on selenium atom exclusively resulted in a formation of vinyl selenide derivatives.     

Reaction of benzo-1,2,3-dithiazolium salts with aromatic amines

The character of a displaceable group depends substantially on the rate of reaction of substituted 6-chloro and 6-methoxy derivatives of benzo-1,2,3-dithiazolium salts, which gives the corresponding 6-phenylaminobenzo-1,2,3-dithiazolium salts. In 4,6-disubstituted benzo-1,2,3-dithiazolium salts, an aniline residue displaces only the substituent in the 6 position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 183–185, February, 1976.     

Reaction of 1,2,3-Selenadiazoles with Phosphines

Nucleophilic attack of tributyl- and triphenylphosphines on 4-phenyl- and 5-ethoxycarbonyl-4-methyl-1,2,3-selenadiazoles leads to the quantitative formation of selenophosphoranes and substituted acetylenes. The molecular structure of 4-phenyl-1,2,3-selenadiazole was confirmed by X-ray crystallography.     

Synthesis and spectroscopic characterisation of 4,5-dihydro-[1,2,3]triazolo[5,1-f][1,2,4]triazines. A novel condensed heterocyclic ring system

The reaction of the 5-bromomethyl-1-dibenzoylamino-1,2,3-triazole ( 5 ) with aromatic amines gave the corresponding 5-arylaminomethyl-1-benzoylamino-1,2,3-triazoles 9 , which on treatment with phosphorus pentachloride gave the [1,2,3]triazolo[5,1-f][1,2,4]triazine derivatives 10 . Hydrolysis of the amide bond in 9 gave the 1-aminotriazoles 11 , which with ethyl orthoformate gave the [1,2,3]triazolo[5,1-f][1,2,4]triazines 12 , whereas with phosgene the triazolotriazinones 13 were obtained. The spectroscopic characteristics of all the new compounds are also given.     

Ion chemistry of 1H-1,2,3-triazole

A combination of experimental methods, photoelectron-imaging spectroscopy, flowing afterglow-photoelectron spectroscopy and the flowing afterglow-selected ion flow tube technique, and electronic structure calculations at the B3LYP/6-311++G(d,p) level of density functional theory (DFT) have been employed to study the mechanism of the reaction of the hydroxide ion (HO-) with 1H-1,2,3-triazole. Four different product ion species have been identified experimentally, and the DFT calculations suggest that deprotonation by HO- at all sites of the triazole takes place to yield these products. Deprotonation of 1H-1,2,3-triazole at the N1-H site gives the major product ion, the 1,2,3-triazolide ion. The 335 nm photoelectron-imaging spectrum of the ion has been measured. The electron affinity (EA) of the 1,2,3-triazolyl radical has been determined to be 3.447 +/- 0.004 eV. This EA and the gas-phase acidity of 2H-1,2,3-triazole are combined in a negative ion thermochemical cycle to determine the N-H bond dissociation energy of 2H-1,2,3-triazole to be 112.2 +/- 0.6 kcal mol-1. The 363.8 nm photoelectron spectroscopic measurements have identified the other three product ions. Deprotonation of 1H-1,2,3-triazole at the C5 position initiates fragmentation of the ring structure to yield a minor product, the ketenimine anion. Another minor product, the iminodiazomethyl anion, is generated by deprotonation of 1H-1,2,3-triazole at the C4 position, followed by N1-N2 bond fission. Formation of the other minor product, the 2H-1,2,3-triazol-4-ide ion, can be rationalized by initial deprotonation of 1H-1,2,3-triazole at the N1-H site and subsequent proton exchanges within the ion-molecule complex. The EA of the 2H-1,2,3-triazol-4-yl radical is 1.865 +/- 0.004 eV.     

Synthesis,Spectroscopic Characterization,Magnetic Properties,and Electronic Structure of New Copper(II) μ-isophthalato Dimers

Synthesis and Properties of 1,2,3-Thiazaboroles, 3-Sulfoimido- and 3-Pseudohalido-1,2,3-dithiaboroles The reactions of 3,4,5-trimethyl- and 4,5-diethyl-3-methyl-1,2,3-dithiaborole with di-t.-butylsulfurdiimide leads to the 1,2,3-thiazaboroles 2 . 3-Bromo-1,2,3-dithiaboroles react with trimethylsilyl-N-sulfinylamine, -isocyanate, and -cyanide by formation of 3-sulfoimido- ( 3 ), 3-isocyanato- ( 4 ), and 3-cyano- ( 5 ) -1,2,3-dithiaboroles. 3-Isothiocyanato-1,2,3-dithiaboroles ( 6 ) are formed by addition of elemental sulfur to 5 . ¹H-, ¹¹B-, ¹³C-, ¹⁴N-, ¹⁵N-NMR-, mass-, and IR spectra are reported and discussed.