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Polynitrogen and Nitrogen-Oxygen Molecular Systems: Synthesis, Reactivity and Application

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Physical Chemistry and Chemical Physics".

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 21566

Special Issue Editor


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Guest Editor
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences 47 Leninsky Prosp., 119991 Moscow, Russia
Interests: nitrogen heterocycles; organic materials; high-energy materials; pharmacologically active compounds; nitric oxide donors; organic synthesis
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Polyheteroatom molecular systems are of paramount importance for the preparation of novel organic and metal–organic functional materials and pharmacologically active substances. In this sense, the synthesis and reactivity of various polyheteroatom heterocycles enriched with nitrogen and oxygen atoms have received special research attention. In addition, structurally diverse acyclic polyheteroatom compounds (e.g., azides and nitro compounds) are considered to be useful precursors for the construction of valuable heterocycles or may serve as standalone organic ligands, components of organic functional and/or energetic materials, or be relevant in medicinal chemistry. This Special Issue plans to provide an overview of the most recent advances in the synthesis and reactivity of polynitrogen and nitrogen–oxygen molecular systems and their applications in diverse areas.

Potential topics include, but are not limited to:

  • the synthesis and reactivity of polynitrogen and nitrogen–oxygen heterocycles;
  • organic azides and click reactions; nitro compounds;
  • mesoionic and zwitter-ionic compounds;
  • polynitrogen and nitrogen–oxygen organic ligands;
  • organic and metal–organic functional materials;
  • pharmacologically active substances.

Prof. Dr. Leonid L. Fershtat
Guest Editor

Manuscript Submission Information

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Keywords

  • nitrogen heterocycles
  • azides
  • nitro compounds
  • mesoionic compounds
  • organic materials
  • cycloaddition and cycloreversion
  • oxidation
  • radical reactions
  • organic ligands
  • transition metal complexes

Published Papers (13 papers)

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Research

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19 pages, 4098 KiB  
Article
Thermochemistry, Tautomerism, and Thermal Stability of 5,7-Dinitrobenzotriazoles
by Igor N. Melnikov, Vitaly G. Kiselev, Igor L. Dalinger, Alexey M. Starosotnikov, Nikita V. Muravyev and Alla N. Pivkina
Int. J. Mol. Sci. 2023, 24(6), 5330; https://doi.org/10.3390/ijms24065330 - 10 Mar 2023
Viewed by 1236
Abstract
Nitro derivatives of benzotriazoles are safe energetic materials with remarkable thermal stability. In the present study, we report on the kinetics and mechanism of thermal decomposition for 5,7-dinitrobenzotriazole (DBT) and 4-amino-5,7-dinitrobenzotriazole (ADBT). The pressure differential scanning calorimetry was employed [...] Read more.
Nitro derivatives of benzotriazoles are safe energetic materials with remarkable thermal stability. In the present study, we report on the kinetics and mechanism of thermal decomposition for 5,7-dinitrobenzotriazole (DBT) and 4-amino-5,7-dinitrobenzotriazole (ADBT). The pressure differential scanning calorimetry was employed to study the decomposition kinetics of DBT experimentally because the measurements under atmospheric pressure are disturbed by competing evaporation. The thermolysis of DBT in the melt is described by a kinetic scheme with two global reactions. The first stage is a strong autocatalytic process that includes the first-order reaction (Ea1I = 173.9 ± 0.9 kJ mol−1, log(A1I/s1) = 12.82 ± 0.09) and the catalytic reaction of the second order with Ea2I = 136.5 ± 0.8 kJ mol−1, log(A2I/s1) = 11.04 ± 0.07. The experimental study was complemented by predictive quantum chemical calculations (DLPNO-CCSD(T)). The calculations reveal that the 1H tautomer is the most energetically preferable form for both DBT and ADBT. Theory suggests the same decomposition mechanisms for DBT and ADBT, with the most favorable channels being nitro-nitrite isomerization and C–NO2 bond cleavage. The former channel has lower activation barriers (267 and 276 kJ mol−1 for DBT and ADBT, respectively) and dominates at lower temperatures. At the same time, due to the higher preexponential factor, the radical bond cleavage, with reaction enthalpies of 298 and 320 kJ mol−1, dominates in the experimental temperature range for both DBT and ADBT. In line with the theoretical predictions of C–NO2 bond energies, ADBT is more thermally stable than DBT. We also determined a reliable and mutually consistent set of thermochemical values for DBT and ADBT by combining the theoretically calculated (W1-F12 multilevel procedure) gas-phase enthalpies of formation and experimentally measured sublimation enthalpies. Full article
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11 pages, 5173 KiB  
Article
Unlocking Kuhn Verdazyls: New Synthetic Approach and Useful Mechanistic Insights
by Fedor E. Teslenko and Leonid L. Fershtat
Int. J. Mol. Sci. 2023, 24(3), 2693; https://doi.org/10.3390/ijms24032693 - 31 Jan 2023
Viewed by 1800
Abstract
An optimized synthetic protocol toward the assembly of Kuhn verdazyls based on an azo coupling of arenediazonium salts with readily available hydrazones followed by the base-mediated cyclization of in situ formed formazans with formalin was developed. The scope and limitations of the presented [...] Read more.
An optimized synthetic protocol toward the assembly of Kuhn verdazyls based on an azo coupling of arenediazonium salts with readily available hydrazones followed by the base-mediated cyclization of in situ formed formazans with formalin was developed. The scope and limitations of the presented method were revealed. Some new mechanistic insights on the formation of Kuhn verdazyls were also conducted. It was found that in contradiction with previously assumed hypotheses, the synthesis of verdazyls was accomplished via an intermediate formation of verdazylium cations which were in situ reduced to leucoverdazyls. The latter underwent deprotonation under basic conditions to generate corresponding anions which coproportionate with verdazylium cations to furnish the formation of Kuhn verdazyls. The spectroscopic and electrochemical behavior of the synthesized verdazyls was also studied. Overall, our results may serve as a reliable basis for further investigation in the chemistry and applications of verdazyls. Full article
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16 pages, 3204 KiB  
Article
Straightforward and Efficient Protocol for the Synthesis of Pyrazolo [4,3-b]pyridines and Indazoles
by Vladislav V. Nikol’skiy, Mikhail E. Minyaev, Maxim A. Bastrakov and Alexey M. Starosotnikov
Int. J. Mol. Sci. 2023, 24(2), 1758; https://doi.org/10.3390/ijms24021758 - 16 Jan 2023
Viewed by 1301
Abstract
An efficient method for the synthesis of pyrazolo [4,3-b]pyridines has been developed on the basis of readily available 2-chloro-3-nitropyridines via a sequence of SNAr and modified Japp–Klingemann reactions. The method offers a number of advantages including utilization of stable arenediazonium tosylates, [...] Read more.
An efficient method for the synthesis of pyrazolo [4,3-b]pyridines has been developed on the basis of readily available 2-chloro-3-nitropyridines via a sequence of SNAr and modified Japp–Klingemann reactions. The method offers a number of advantages including utilization of stable arenediazonium tosylates, operational simplicity as well as combining the azo-coupling, deacylation and pyrazole ring annulation steps in a one-pot manner. An unusual rearrangement (C-N-migration of the acetyl group) was observed and a plausible mechanism was proposed based on the isolated intermediates and NMR experiments. In addition, the developed protocol was successfully applied to the synthesis of 1-arylindazoles combining the Japp–Klingemann reaction and cyclization of the resulting hydrazone as a one-pot procedure. Full article
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11 pages, 29632 KiB  
Article
N-Functionalization of 5-Aminotetrazoles: Balancing Energetic Performance and Molecular Stability by Introducing ADNP
by Jin Xiong, Jinjie Chang, Jinxiong Cai, Ping Yin and Siping Pang
Int. J. Mol. Sci. 2022, 23(24), 15841; https://doi.org/10.3390/ijms232415841 - 13 Dec 2022
Cited by 3 | Viewed by 1543
Abstract
5-aminotetrazole is one of the most marked high-nitrogen tetrazole compounds. However, the structural modification of 5-aminotetrazole with nitro groups often leads to dramatically decreased molecular stability, while the N-bridging functionalization does not efficiently improve the density and performance. In this paper, we report [...] Read more.
5-aminotetrazole is one of the most marked high-nitrogen tetrazole compounds. However, the structural modification of 5-aminotetrazole with nitro groups often leads to dramatically decreased molecular stability, while the N-bridging functionalization does not efficiently improve the density and performance. In this paper, we report on a straightforward approach for improving the density of 5-aminotetrazole by introducing 4-amino-3,5-dinitropyrazole. The following experimental and calculated properties show that nitropyrazole functionalization competes well with energetic performance and mechanic sensitivity. All compounds were thoroughly characterized using IR and NMR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). Two energetic compounds (DMPT-1 and DMPT-2) were further confirmed by implementing single-crystal X-ray diffraction studies. Compound DMPT-1 featured a high crystal density of 1.806 g cm−3, excellent detonation velocity (vD = 8610 m s−1), detonation pressure (P = 30.2 GPa), and impact sensitivity of 30 J. Full article
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11 pages, 1201 KiB  
Article
Annulation of Perimidines with 5-Alkynylpyrimidines en Route to 7-Formyl-1,3-Diazopyrenes
by Stanislav V. Shcherbakov, Alexander V. Aksenov, Maksim V. Vendin, Viktoria Yu. Shcherbakova, Anna Yu. Ivanova, Maksim O. Shcheglov, Sergei N. Ovcharov and Michael Rubin
Int. J. Mol. Sci. 2022, 23(24), 15657; https://doi.org/10.3390/ijms232415657 - 10 Dec 2022
Viewed by 1068
Abstract
Unusual rearrangements were shown to accompany Brønsted acid-assisted peri-annulations of 1H-perimidines with 5-alkynylpyrimidines. These transformations take different routes depending on the nature of acetylene precursor, and lead to the formation of 7-formyl-1,3-diazopyrenes. Full article
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21 pages, 4545 KiB  
Article
Water-Soluble Salts Based on Benzofuroxan Derivatives—Synthesis and Biological Activity
by Elena Chugunova, Victoria Matveeva, Alena Tulesinova, Emil Iskanderov, Nurgali Akylbekov, Alexey Dobrynin, Ayrat Khamatgalimov, Nurbol Appazov, Lyazat Boltayeva, Bakhytzhan Duisembekov, Mukhtar Zhanakov, Yulia Aleksandrova, Tatyana Sashenkova, Elena Klimanova, Ugulzhan Allayarova, Anastasia Balakina, Denis Mishchenko, Alexander Burilov and Margarita Neganova
Int. J. Mol. Sci. 2022, 23(23), 14902; https://doi.org/10.3390/ijms232314902 - 28 Nov 2022
Cited by 2 | Viewed by 2234
Abstract
A series of novel water-soluble salts of benzofuroxans was achieved via aromatic nucleophilic substitution reaction of 4,6-dichloro-5-nitrobenzofuroxan with various amines. The salts obtained showed good effectiveness of the pre-sowing treatment of seeds of agricultural crops at concentrations of 20–40 mmol. In some cases, [...] Read more.
A series of novel water-soluble salts of benzofuroxans was achieved via aromatic nucleophilic substitution reaction of 4,6-dichloro-5-nitrobenzofuroxan with various amines. The salts obtained showed good effectiveness of the pre-sowing treatment of seeds of agricultural crops at concentrations of 20–40 mmol. In some cases, the seed treatment with salts leads not only to improved seed germination, but also to the suppression of microflora growth. Additionally, their anti-cancer activityin vitrohas been researched. The compounds with morpholine fragments or a fragment of N-dimethylpropylamine, demonstrated the highest cytotoxic activity, which is in good correlation with the ability to inhibit the glycolysis process in tumor cells. Two compounds 4e and 4g were selected for further experiments using laboratory animals. It was found that the lethal dose of 50% (LD50) is 22.0 ± 1.33 mg/kg for 4e and 13.75 ± 1.73 mg/kg for 4g, i.e., compound 4e is two times less toxic than 4g, according to the mouse model in vivo. It was shown that the studied compounds exhibit antileukemia activity after a single intraperitoneal injection at doses from 1.25 to 5 mg/kg, as a result of which the average lifespan of animals with a P388 murine leukemia tumor increases from 20 to 28%. Thus, the water-soluble salts of benzofuroxans can be considered as promisingcandidates for further development, both as anti-cancer agents and as stimulants for seed germination and regulators of microflora crop growth. Full article
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18 pages, 2906 KiB  
Article
Acid-Switchable Synthesis of Trifluoromethylated Triazoles and Isoxazoles via Reaction of CF3-Ynones with NaN3: DFT Study of the Reaction Mechanism
by Vasiliy M. Muzalevskiy, Zoia A. Sizova, Mikhail S. Nechaev and Valentine G. Nenajdenko
Int. J. Mol. Sci. 2022, 23(23), 14522; https://doi.org/10.3390/ijms232314522 - 22 Nov 2022
Cited by 3 | Viewed by 1441
Abstract
A detailed study of the reaction of CF3-ynones with NaN3 was performed. It was found that the reaction permits the selective synthesis of either 4-trifluoroacetyltriazoles or 5-CF3-isoxazoles. The chemoselectivity of the reaction was switchable via acid catalysis. The [...] Read more.
A detailed study of the reaction of CF3-ynones with NaN3 was performed. It was found that the reaction permits the selective synthesis of either 4-trifluoroacetyltriazoles or 5-CF3-isoxazoles. The chemoselectivity of the reaction was switchable via acid catalysis. The reaction of CF3-ynones with NaN3 in EtOH produced high yields of 4-trifluoroacetyltriazoles. In contrast, the formation of 5-CF3-isoxazoles was observed under catalysis by acids. This acid-switchable procedure can be performed at sub-gram scale. The possible reaction mechanism was supported by DFT calculations. The synthetic utility of the prepared 4-trifluoroacetyltriazoles was demonstrated. Full article
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8 pages, 2327 KiB  
Article
Coordinative Combination of Nitroamine and Gem-Dinitromethyl with Fused Ring for Enhanced Oxygen Balances and Detonation Properties
by Xun Zhang, Yaxi Wang, Xinyuan Zhao, Chunlin He and Siping Pang
Int. J. Mol. Sci. 2022, 23(22), 14337; https://doi.org/10.3390/ijms232214337 - 18 Nov 2022
Viewed by 1291
Abstract
Oxygen balance and heat of formation are closely related to the nitrogen and oxygen content in a molecule and have a significant effect on the detonation performance of energetic materials. Here a new family of 1,2,4-triazolo [4,3-b][1,2,4,5]-tetrazine containing gem-dinitromethyl and nitroamine with high [...] Read more.
Oxygen balance and heat of formation are closely related to the nitrogen and oxygen content in a molecule and have a significant effect on the detonation performance of energetic materials. Here a new family of 1,2,4-triazolo [4,3-b][1,2,4,5]-tetrazine containing gem-dinitromethyl and nitroamine with high nitrogen-oxygen content was synthesized and characterized. Moreover, the structure of the guanidine salt (3) and TATOT salt (4) were confirmed by single-crystal X-ray diffraction. The nitrogen and oxygen content of ammonium salt 2 reached 82.5%, with a high density (1.805 g cm−3) and high detonation properties (D = 8900 m s−1; P = 32.4 GPa), which were similar to those of RDX. Full article
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13 pages, 5304 KiB  
Article
Pyrolysis Kinetics and Combustion Behaviors of a High-Nitrogen Compound, 4,4′-Azobis(1,2,4-triazole)
by Qi Pan, Honglei Zhang, Xueyong Guo, Sen Sun and Shenghua Li
Int. J. Mol. Sci. 2022, 23(19), 11313; https://doi.org/10.3390/ijms231911313 - 25 Sep 2022
Cited by 4 | Viewed by 1314
Abstract
To study the thermal decomposition behavior of 4,4′-azobis(1,2,4-triazole) (ATRZ), the non-isothermal thermal decomposition kinetics of ATRZ were studied using the thermogravimetric–differential scanning calorimetry (TG–DSC) method. The TG–DSC of ATRZ was analyzed at heating rates of 5, 10, 15, and 20 K·min−1 in [...] Read more.
To study the thermal decomposition behavior of 4,4′-azobis(1,2,4-triazole) (ATRZ), the non-isothermal thermal decomposition kinetics of ATRZ were studied using the thermogravimetric–differential scanning calorimetry (TG–DSC) method. The TG–DSC of ATRZ was analyzed at heating rates of 5, 10, 15, and 20 K·min−1 in an argon atmosphere. The thermal decomposition kinetic parameters at peak temperature (Tp), such as apparent activation energy (Ea) and pre-exponential factor (lgA) of ATRZ, were calculated using the Kissinger, Ozawa, and Satava–Sestak methods. Ea and lgA calculated using the Kissinger, Ozawa, and Satava–Sestak methods are very close, at 780.2 kJ·mol−1/70.5 s−1, 751.1 kJ·mol−1/71.8 s−1, and 762.1 kJ·mol−1/71.8 s−1, respectively. Using a combination of three methods, the reaction mechanism function g(α) of ATRZ was obtained. The results show that the decomposition temperature of ATRZ is about 310 °C, and the decomposition is rapidly exothermic. The pyrolysis path of ATRZ was investigated through a pyrolysis-gas chromatography mass spectrometry (PY-GC/MS) experiment. ATRZ has three different decomposition paths and finally generates N2, HC-N-CH, N≡C-N, and HC=N-C≡N. The laser ignition combustion duration of ATRZ was 0.5033 s and the peak temperature was 1913 °C. The laser ignition combustion duration of ATRZ+CL-20 was 1.0277 s and the peak temperature was 2105 °C. The rapid energy release rate of ATRZ promotes the combustion energy release of CL-20. Full article
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10 pages, 2098 KiB  
Article
A Convenient Way to Quinoxaline Derivatives through the Reaction of 2-(3-Oxoindolin-2-yl)-2-phenylacetonitriles with Benzene-1,2-diamines
by Alexander V. Aksenov, Nikolai A. Arutiunov, Dmitrii A. Aksenov, Artem V. Samovolov, Igor A. Kurenkov, Nicolai A. Aksenov, Elena A. Aleksandrova, Daria S. Momotova and Michael Rubin
Int. J. Mol. Sci. 2022, 23(19), 11120; https://doi.org/10.3390/ijms231911120 - 22 Sep 2022
Cited by 3 | Viewed by 1461
Abstract
Microwave-assisted reaction between 2-(3-oxoindolin-2-yl)-2-phenylacetonitriles andbenzene-1,2-diamines leads to the high-yielding formation of the corresponding quinoxalines as sole, easily isolaable products. The featured transformation involves unusual extrusion of phenylacetonitrile molecule and could be performed in a short sequence starting from commonly available indoles and nitroolefins. [...] Read more.
Microwave-assisted reaction between 2-(3-oxoindolin-2-yl)-2-phenylacetonitriles andbenzene-1,2-diamines leads to the high-yielding formation of the corresponding quinoxalines as sole, easily isolaable products. The featured transformation involves unusual extrusion of phenylacetonitrile molecule and could be performed in a short sequence starting from commonly available indoles and nitroolefins. Full article
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19 pages, 6710 KiB  
Article
Ultrasonic-Assisted Synthesis of Benzofuran Appended Oxadiazole Molecules as Tyrosinase Inhibitors: Mechanistic Approach through Enzyme Inhibition, Molecular Docking, Chemoinformatics, ADMET and Drug-Likeness Studies
by Ali Irfan, Ameer Fawad Zahoor, Shagufta Kamal, Mubashir Hassan and Andrzej Kloczkowski
Int. J. Mol. Sci. 2022, 23(18), 10979; https://doi.org/10.3390/ijms231810979 - 19 Sep 2022
Cited by 11 | Viewed by 2436
Abstract
Furan-oxadiazole structural hybrids belong to the most promising and biologically active classes of oxygen and nitrogen containing five member heterocycles which have expanded therapeutic scope and potential in the fields of pharmacology, medicinal chemistry and pharmaceutics. A novel series 5a–j of benzofuran-oxadiazole molecules [...] Read more.
Furan-oxadiazole structural hybrids belong to the most promising and biologically active classes of oxygen and nitrogen containing five member heterocycles which have expanded therapeutic scope and potential in the fields of pharmacology, medicinal chemistry and pharmaceutics. A novel series 5a–j of benzofuran-oxadiazole molecules incorporating S-alkylated amide linkage have been synthesized using ultrasonic irradiation and screened for bacterial tyrosinase inhibition activity. Most of the synthesized furan-oxadiazole structural motifs exhibited significant tyrosinase inhibition activity in the micromolar range, with one of the derivatives being more potent than the standard drug ascorbic acid. Among the tested compounds, the scaffold 5a displayed more tyrosinase inhibition efficacy IC50 (11 ± 0.25 μM) than the ascorbic acid IC50 (11.5 ± 0.1 μM). Compounds 5b, 5c and 5d efficiently inhibited bacterial tyrosinase with IC50 values in the range of 12.4 ± 0.0–15.5 ± 0.0 μM. The 2-fluorophenylacetamide containing furan-oxadiazole compound 5a may be considered as a potential lead for tyrosinase inhibition with lesser side effects as a skin whitening and malignant melanoma anticancer agent. Full article
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7 pages, 1599 KiB  
Article
Boosting the Energetic Performance of Trinitromethyl-1,2,4-oxadiazole Moiety by Increasing Nitrogen-Oxygen in the Bridge
by Peng Chen, Hui Dou, Chunlin He and Siping Pang
Int. J. Mol. Sci. 2022, 23(17), 10002; https://doi.org/10.3390/ijms231710002 - 2 Sep 2022
Cited by 5 | Viewed by 1777
Abstract
The trinitromethyl moiety is a useful group for the design and development of novel energetic compounds with high nitrogen and oxygen content. In this work, by using an improved nitration method, the dinitromethyl precursor was successfully nitrated to the trinitromethyl product (2 [...] Read more.
The trinitromethyl moiety is a useful group for the design and development of novel energetic compounds with high nitrogen and oxygen content. In this work, by using an improved nitration method, the dinitromethyl precursor was successfully nitrated to the trinitromethyl product (2), and its structure was thoroughly characterized by FTIR, NMR, elemental analysis, differential scanning calorimetry, and single-crystal X-ray diffraction. Compound 2 has a high density (1.897 g cm−3), high heat of formation (984.8 kJ mmol−1), and a high detonation performance (D: 9351 m s−1, P: 37.46 GPa) that may find useful applications in the field of high energy density materials. Full article
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Review

Jump to: Research

22 pages, 17704 KiB  
Review
Recent Advances in the Chemistry of Saturated Annulated Nitrogen-Containing Polycyclic Compounds
by Victor Yu. Kirsanov and Elena B. Rakhimova
Int. J. Mol. Sci. 2022, 23(24), 15484; https://doi.org/10.3390/ijms232415484 - 7 Dec 2022
Cited by 3 | Viewed by 1690
Abstract
This review is devoted to the analysis of works published over the past 20 years on the chemistry of saturated annulated nitrogen-containing polycyclic compounds, the molecules of which consist of four, five, six, and seven cycles, and contain from one to eight endocyclic [...] Read more.
This review is devoted to the analysis of works published over the past 20 years on the chemistry of saturated annulated nitrogen-containing polycyclic compounds, the molecules of which consist of four, five, six, and seven cycles, and contain from one to eight endocyclic nitrogen atoms. Full article
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