EFFECTIVE METHODS FOR CONSTRUCTING MACROHETERO- AND METALHETEROCYCLES WITH THE PARTICIPATION OF CATALYSTS BASED ON RARE-EARTH AND TRANSITION METALS

Current trends in synthetic organic chemistry require a transition from multi-stage methods for obtaining target molecules to single-stage reactions while maintaining the overall efficiency and selectivity of the methods used. This is especially important for the production of complex heterocyclic compounds with biological activity and a complex of useful chemical properties. Heterocycles are widespread in nature, are part of complex chemical structures and play a key role in animal metabolism. The introduction of heteroatoms (oxygen, nitrogen, sulfur) into the macrocyclic skeleton promotes their specific binding to metal ions and changes in the chemical properties of macrocycles. The selectivity of macrocycle binding of ions of various metals and organic ions is regulated by the type, number and position of heteroatoms in the ring, the size of the cycle, as well as the presence of function al groups in the ring. The most well-known and significant representatives of heterocyclic compounds with wide practical application include O,N-, O-O-CH2N(S,P)-, S,N- and O,S,N-containing heterocycles, which possess a complex of beneficial properties and have proven themselves to be effective antioxidant, fungicidal, antimicrobial, antitumor and anti-inflammatory agents, as well as rare metal sorbents and selective complexing agents. To obtain O,S, and N-containing macrocycles, as a rule, multi-stage syntheses based on a combination of cross-coupling reactions, heterocyclization, recycling, and esterification are used. Most of the reactions described above are multi-stage and have low selectivity. Unlike thermal methods, catalytic methods for producing heterocycles repre sent a relatively new and constantly developing field of organic synthesis. Catalytic reactions make it possible to obtain heterocycles with high selectivity due to the nucleophilic addition of heteroatoms to carbonyl compounds, acetylenes and other substrates. Such reactions include Michael addition, cycloaddition, olefin metathesis, cross-combination, introduction of carbenoids along the heteroatom-H bond, opening of small cycles and acetylene-allene rearrangements. Catalytic methods make it possible to efficiently involve small molecules that are not active under normal conditions, such as CO2, CO or ethylene, in reactions for the synthesis of heterocycles. The rapid development of catalytic reactions has led to an understanding of the need to develop effective methods for constructing heterocyclic compounds of diverse structures. Taking into account the prospects of fundamental research in the field of synthesis of macrocyclic heteroatomic compounds and their increasing practical application as potential biologically active substances and materials with a complex of useful properties, the development of preparative methods for the selective synthesis of new types of O,N-, S,N containing macrohetero(metallo)cycles under mild conditions involving available starting reagents and catalysts is an important and urgent task. The article describes effective methods for constructing macrohetero(O,S,N,P)- and metal(Al,Si)hetero(O,S,N)cycles involving catalysts based on rare earths and transition metals, which were developed under the strict guidance of Dr. of Chemical Sciences, Professor A.G. Ibragimov.