The chemistry of heterocyclic compounds has traditionally been and remains a bright area of chemical science in Russia. This is due to the fact that many heterocycles find the widest application. These compounds are the key structural fragments of most drugs, plant protection agents. Many natural compounds are also derivatives of heterocycles. At present, more than half of the hundreds of millions of known chemical compounds are heterocycles. This collective review is devoted to the achievements of Russian chemists in this field over the last 15–20 years. The review presents the achievements of leading heterocyclists representing both RAS institutes and university science. It is worth noting the wide scope of the review, both in terms of the geography of author teams, covering the whole of our large country, and in terms of the diversity of research areas. Practically all major types of heterocycles are represented in the review. The special attention is focused on the practical applications of heterocycles in the design of new drugs and biologically active compounds, high-energy molecules, materials for organic electronics and photovoltaics, new ligands for coordination chemistry, and many other rapidly developing areas. These practical advances would not be possible without the development of new fundamental transformations in heterocyclic chemistry. Bibliography — 2237 references.

First described by the groups of Sharpless (Rostovtsev et al., Angew. Chem., Int. Ed., 2002, 41, 2596) and Meldal (Tornøe et al., J. Org. Chem., 2002, 67, 3057) in 2002, Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC) became one of the most effective and reliable synthetic tools in diverse areas of modern chemistry, such as organic, medicinal and polymer chemistry, material science and chemical biology. The advantages of this reaction are high selectivity, simple reaction conditions, wide scope and excellent functional group tolerance. This efficient transformation can be used for the synthesis of various 1,2,3-triazoles. On the other hand, CuAAC can be efficiently used for bioconjugation of two units bearing alkyne and azide functions via the triazole moiety. Moreover, the use of azides and alkynes bearing orthogonal functional groups in this reaction opens broad opportunities for the synthesis of valuable polyfunctionalized triazole-containg molecules. Thus, the initial discussion is focused on synthetic applications of functionally substituted azides and terminal alkynes in the CuAAC, combined with other transformations. The prominent part of this review is devoted to an application of these bi (or tri)-functional reagents for the design, synthesis or labeling of biologically active molecules.

After the appearance of the green chemistry concept, which was introduced in the chemistry vocabulary in the early 1990s, its main statements have been continuously developed and modified. Currently, there are 10–12 cornerstones that should form the basis for an ideal chemical process. This review analyzes the accumulated experience and achievements towards the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. The review presents the views of leading Russian scientists specializing in various fields of this subject, including homogeneous and heterogeneous catalysis, fine and basic organic synthesis, electrochemistry, polymer chemistry, chemistry based on bio-renewable feedstocks and chemistry of energetic compounds and materials. A new approach to the quantitative evaluation of the environmental friendliness of processes developed by Russian authors is described. The bibliography includes 1761.