TOOLKIT OF EFFECTIVE REAGENTS IN THE CHEMISTRY OF HETEROATOM CONTAINING COMPOUNDS (MINI-REVIEW)

The mini-review presents the achievements of Ufa scientists, implemented under the supervision of Profes sor A.G. Ibragimov, in the field of heterocycle synthesis based on transition metal-catalyzed two-component reac tions of cyclocondensation, recyclization, transamination, cyclothio- and aminomethylation of N,O,S-nucleophiles with reagents that have a latent formaldehyde form in the structure. Taking into account the efficiency of such reagents, we systematized the material, ranking them into the following tools: N,N-bis(methoxyalkyl)-N-amines, bis(dimethylaminomethane), dimethylamino disulfides, N-aryl-1,5,3-dioxazepanes, 1,3,6-oxadithiepane, aryl 1,3,5-triazinanes, N-substituted 1,3,5-dithiazinanes, bis(oxazolidin-3-yl)methane, glycoluril, and 1,4,5,8 tetraazadecalin. The highest catalytic activity in reagent activation was demonstrated by commercially available salts of transition and rare earth metals (Sm(NO3)3∙6H2O, NiCl2∙6H2O, CuCl, FeCl3∙6H2O, YbCl3∙6H2O). A possi ble mechanism of reactions occurring under Lewis acid catalysis is a mixed SN1–SN2 type, the key stages of which are the coordination of catalyst metal ions to the heteroatom of the reactants, the addition of nucleophiles to the formed carbocation, and the subsequent elimination of leaving groups. The value of the obtained reagents lies in the possibility of obtaining a wide combinatorial series of saturated heterocyclic systems with six-, seven-, and eight-membered nuclei, cyclophanes, and macrocyclic compounds.