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Renaissance of 1,2,5-Oxadiazolyl Diazonium Salts: Synthesis and Reactivity
European Journal of Organic Chemistry. 2019. Vol. 26. P. 4248–4259.
A new approach for the synthesis and reactivity of the 1,2,5-oxadiazolyl diazonium salts is represented. A simple and direct protocol to previously inaccessible furoxanyl and furazanyl diazonium salts was developed for the first time. Azo coupling reactions of thus obtained diazonium salts with a series of structurally diverse CH-acids have been also successfully performed. Therefore, this study reveals new horizons for the use of furoxanyl and furazanyl diazonium salts in organic chemistry.
Sofya P. Balabanova, Alexey A. Voronin, Churakov A. et al., CrystEngComm 2024 Vol. 25 P. 3349–3362
A comparative study of experimentally established structures, stability and energetic performance of ammonium and hydrazinium salts of 4H-[1,2,3]triazolo[4,5-c][1,2,5]oxadiazole (triazolofurazan, TF) as well as its N-oxide and N-nitroimide was performed. The aim of this study was to reveal the structure–property relationships of heterocyclic systems by the example of triazolofurazan derivatives. It was shown that the introduction of N-oxide oxygen ...
Added: March 7, 2025
Балабанова С. П., Voronin A., Churakov A. et al., Mendeleev Communications 2024 Vol. 34 No. 6 P. 862–864
Two thermostable representatives of methyl-substituted triazolofurazan derivatives with zwitterionic N+N– bonds were obtained via the thermal cyclization of N,N’-bis(azidofurazanyl)-N-methyltriazene. 5-(N-Azidofurazanyl-N-methylamino)triazolofurazan was the product of known intramolecular reaction of neighboring azido and azo groups. Its isomer with methyl group in the triazolofurazan core was formed in the course of new cyclization of azido and triazene groups representing an original NN ...
Added: March 7, 2025
Fedorenko A., Ivanova V., Minyaev M. E. et al., ChemistrySelect 2023 Vol. 8 No. 43 Article e202303122
General method for the annulation of [1,2,5]thiadiazole ring to pyridine and benzene cycle has been developed using sulfur monochloride as a sulfur source. On this basis a number of [1,2,5]thiadiazolo[4,3-b]pyridines and benzo[c]thiadiazoles were synthesized. The most π-deficient [1,2,5]thiadiazolo[4,3-b]pyridines readily react with neutral carbon nucleophiles such as CH-acids, indoles, pyrrole and phloroglucinol to give 1,4-adducts. ...
Added: February 14, 2024
Shaferov A., Sergey T. Arakelov, Teslenko F. et al., Chemistry - A European Journal 2023 Vol. 29 No. 44 Article e202300948
The development of liquid energetic fuels with improved properties is an important topic in space propulsion technologies. In this manuscript, a series of energetic ionic liquids incorporating a 1,2,5-oxadiazole ring and nitrate, dicyanamide or dinitramide anion was synthesized and their physicochemical properties were evaluated. The synthesized compounds were fully characterized and were found to have ...
Added: November 22, 2023
Stebletsova I., Alexander A. Larin, Ivan V. Ananyev et al., Molecules 2023 Vol. 28 No. 19 Article 6969
A facile and efficient method for the regioselective [3 + 2] cycloaddition of 4-azidofuroxans to 1-dimethylamino-2-nitroethylene under p-TSA catalysis affording (4-nitro-1,2,3-triazolyl)furoxans was developed. This transformation is believed to proceed via eliminative azide–olefin cycloaddition resulting in its complete regioselectivity. The developed protocol has a broad substrate scope and enables a straightforward assembly of the 4-nitro-1,2,3-triazole motif. Moreover, ...
Added: October 12, 2023
Voronin A., Sofya P. Balabanova, Fedyanin I. et al., Molecules 2022 Vol. 27 No. 19 Article 6287
A strategy for the synthesis of 5-((2-cyanoethyl)-X-amino)-[1,2,3]triazolo[4,5-c][1,2,5]oxadiazol-5-ium-4-ides (X = H; CH2CH2CN; NO2 (4a); CN (4b); CO2Et (4c)) starting from 3-amino-4-azido-1,2,5-oxadiazole was developed. The key step in this strategy is the intramolecular thermolytic cyclization of the azido group and the bis(2-cyanoethyl)triazene group. Removal of the 2-cyanoethyl protecting group from amides 4a–c gave potassium salt of the corresponding nitramide and ...
Added: January 31, 2023
Zhilin E., Ivan V. Ananyev, Pivkina A. et al., Dalton Transactions 2022 Vol. 51 No. 37 P. 14088–14096
Nitrogen-oxygen organic materials constitute an important family of multipurpose high-energy materials. However, the preparation of energetic boosters and oxidizers for various civil and space technologies remains a challenging task and such materials usually require special precautions and fine tunability of their functional properties. To find a balance between energy and safety while retaining the oxidizing ...
Added: October 24, 2022
Fershtat, Leonid L., Teslenko F., Synthesis 2021 Vol. 53 No. 20 P. 3673–3682
Five-membered heterocyclic N-oxides attract special attention due to their significant potential applications in medicinal chemistry and advanced materials science. In this regard, novel methods for their synthesis and functionalization are in constant demand. In this short review, recent state-of-the-art achievements in the chemistry of isoxazoline N-oxides, 1,2,3-triazole 1-oxides and 1,2,5-oxadiazole 2-oxides are summarized. The main ...
Added: September 12, 2022
Чаплыгин D., Gorbunov Y., Leonid L. Fershtat, Asian Journal of Organic Chemistry 2021 Vol. 10 No. 10 P. 2644–2653
A regioselective method for an assembly of pharmacologically relevant fully substituted furoxans and isoxazoles using the ring distortion diversity-oriented approach through the one-pot ring cleavage/nucleophilic addition/oxidation cascade of monosubstituted furoxans was developed. The described synthetic strategy is highly regioselective and provides single furoxan regioisomers upon utilization of N- or S-nucleophiles. Utilization of the cyanide-anion as ...
Added: September 12, 2022
Larin A. A., Shaferov A. V., Monogarov K. A. et al., Mendeleev Communications 2022 Vol. 32 No. 1 P. 111–113
A series of novel, structurally diverse 1,2,4- and 1,2,5-oxadiazole assemblies was synthesized from readily available furoxanyl precursors. Experimentally determined physico-chemical properties and calculated detonation parameters showed an application potential of the prepared nitrogen-oxygen molecular systems as promising energetic materials. ...
Added: September 11, 2022
Trainov K., Chechekina O., Salikov R. et al., Dyes and Pigments 2021 Vol. 187 Article 109132
The use of stabilized exocyclic cyclopentadienone enolate, containing three ester groups and a dicyanomethylene fragment, allowed the replacement of unstable cyclopentadienones in the synthesis of arylhydrazonopentadiene chromophores. The presence of reaction centers in the resulting chromophores allowed three additional series of compounds to be obtained. Two series of compounds lost coplanarity in conjugated systems and ...
Added: September 28, 2021
Larin A., Shaferov A., Epishina M. et al., ACS Applied Energy Materials 2020 Vol. 3 No. 8 P. 7764–7771
Several energy-rich bifuroxans incorporating nitro and azido functionalities have been synthesized and thoroughly characterized by IR and multinuclear NMR spectroscopy, elemental analyses, single-crystal X-ray diffraction, and differential scanning calorimetry. N-oxide regiochemistry was employed to design the tunable azido(nitro)bifuroxans with different physicochemical and energetic properties. All synthesized compounds have high enthalpies of formation (449-777 kJ mol(-1)) ...
Added: April 12, 2021
Chaplygin D., Ananyev I., Fershtat L. et al., Synthesis 2020 Vol. 52 No. 18 P. 2667–2678
A novel method for the synthesis of a diverse series of functionally substituted five-membered heterocyclic compounds via atom-economic, regio-, and diastereoselective one-pot reaction cascade was developed. This approach involves a ring opening in 4-arylfuroxans to alpha-oximinoarylacetonitrile oxides followed by [3+2] cycloaddition to various dipolarophiles to afford multisubstituted isoxazoles and isoxazolines. Subsequent azole-azole rearrangement of (oximino)isoxazolines/-isoxazoles, ...
Added: April 12, 2021
Anikin O., Leonov N., Klenov M. et al., European Journal of Organic Chemistry 2019 No. 26 P. 4189–4195
7‐Nitro‐3‐(nitro‐NNO‐azoxy)[1,2,4]triazolo[5,1‐c][1,2,4]‐triazin‐4‐amine (4) is the first high‐melting compound bearing adjacent nitro‐NNO‐azoxy and amino groups. It was synthesized by nitration of 7‐nitro‐3‐(tert‐butyl‐NNO‐azoxy)[1,2,4]triazolo[5,1‐c][1,2,4]triazin‐4‐amine (3) with NO2BF4. Compound 4 is a rather thermally stable (decomposition onset temperature 154 °C), highly energetic (calculated heat of formation 580 kcal·kg–1), and highly dense (1.875 g cm–3) material with a CO‐level oxygen balance. ...
Added: October 15, 2020
Ananyev I., Тесленко Ф. Е., Чураков А. et al., Tetrahedron Letters 2020 Vol. 61 No. 13 P. 151678-1–151678-5
A novel one-pot approach for the synthesis of 1,2,4- and 1,2,5-oxadiazole ring assemblies has been developed. The synthetic strategy involves the condensation of furoxanyl amidoximes with aldehydes and subsequent iodine-mediated oxidation of the intermediate 1,2,4-oxadiazolines. The analogous reaction of 4-aminofuroxanyl-3-carboxamidoxime results not only in formation of the 1,2,4-oxadiazole subunit, but also rearrangement of the furoxan ...
Added: August 11, 2020
Zhilin E., Bystrov D., Ananyev I. et al., Chemistry - A European Journal 2019 Vol. 25 No. 63 P. 14284–14289
A novel one-pot cascade method for the assembly of valuable NO-donor azasydnone scaffold has been developed. This construction strategy involves a diazotization/azo coupling/elimination/double rearrangement cascade sequence of readily available amines. The current protocol enables the generation of a diverse array of azasydnones, including previously hardly accessible heteroaryl substituted azasydnones (25 examples, 70-97% yield) with a ...
Added: October 4, 2019