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This Review covers the synthesis and performance of the most promising 1,2,5-oxadiazole-based high-energy density materials (HEDMs). These materials comprise a 1,2,5-oxadiazole subunit as a key structural motif linked to various acyclic explosophoric groups or to nitrogen-rich and nitrogen-oxygen azoles: 1,2,4triazole, tetrazole, 1,2,4-and 1,3,4-oxadiazoles. Energetic alliances of two and more 1,2,5-oxadiazole rings linked directly or through heteroatom spacers are also presented. Particular attention is devoted to the installation of different explosophores: nitro, nitramino, azo, azoxy, dinitromethyl, trinitroethyl moieties and their combination. Promising environmentally benign energetic materials with high detonation velocity and pressure, and outstanding insensitivity are summarized. Overall, the presented materials may be considered as next-generation high-performance energetic materials that are superior to commonly used traditional explosives (TNT, PETN, RDX, HMX).

A series of highly energetic organic salts comprising a tetrazolylfuroxan anion, explosophoric azido or azo functionalities, and nitrogen‐rich cations were synthesized by simple, efficient, and scalable chemical routes. These energetic materials were fully characterized by IR and multinuclear NMR (1H, 13C, 14N, 15N) spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). Additionally, the structure of an energetic salt consisting of an azidotetrazolylfuroxan anion and a 3,6,7‐triamino‐7H‐[1,2,4]triazolo[4,3‐b][1,2,4]triazolium cation was confirmed by single‐crystal X‐ray diffraction. The synthesized compounds exhibit good experimental densities (1.57–1.71 g cm−3), very high enthalpies of formation (818–1363 kJ mol−1), and, as a result, excellent detonation performance (detonation velocities 7.54–8.26 kms−1 and detonation pressures 23.4–29.3 GPa). Most of the synthesized energetic salts have moderate sensitivity toward impact and friction, which makes them promising candidates for a variety of energetic applications. At the same time, three compounds have impact sensitivity on the primary explosives level (1.5–2.7 J). These results along with high detonation parameters and high nitrogen contents (66.0–70.2 %) indicate that these three compounds may serve as potential environmentally friendly alternatives to lead‐based primary explosives.

The review is devoted to modern trends in the chemistry of nitrogen-, oxygen-and sulfur-containing monocyclic, polynuclear and benzo(hetero)annulated heterocyclic compounds. Methods for the synthesis and chemical reactivity of furazan, furoxan, thiazole, thiadiazole, dithiazole, thiophene, glycoluril, imidazotriazine, diaziridine and other heterocycles are discussed. Characteristic features of reactions depending on the structure of the starting compounds, intermediates and reaction medium (organic solvents, ionic liquids) and mechanistic aspects of the most interesting transformations are considered. Data on the biological activities and prospects for practical applications of the indicated heterocyclic systems are presented. The bibliography includes 383 references.

A global increase in environmental pollution demands the development of new "cleaner" chemical processes. Among urgent improvements, the replacement of traditional hydrocarbon-derived toxic organic solvents with neoteric solvents less harmful for the environment is one of the most vital issues. As a result of the favorable combination of their unique properties, ionic liquids (ILs), dense gases, and supercritical fluids (SCFs) have gained considerable attention as suitable green chemistry media for the preparation and modification of important chemical compounds and materials. In particular, they have a significant potential in a specific and very important area of research associated with the manufacture and processing of high-energy materials (HEMs). These large-scale manufacturing processes, in which hazardous chemicals and extreme conditions are used, produce a huge amount of hard-to-dispose-of waste. Furthermore, they are risky to staff, and any improvements that would reduce the fire and explosion risks of the corresponding processes are highly desirable. In this Review, useful applications of almost nonflammable ILs, dense gases, and SCFs (first of all, CO ) for nitration and other reactions used for manufacturing HEMs are considered. Recent advances in the field of energetic (oxygen-balanced and hypergolic) ILs are summarized. Significant attention is paid to the SCF-based micronization techniques, which improve the energetic performance of HEMs through an efficient control of the morphology and particle size distribution of the HEM fine particles, and to useful applications of SCFs in HEM processing that makes them less hazardous.