The present work aimed to study the potential of well-known synthetic strategies for the synthesis of imidazo[4,5-b]pyridine-derived (or 1-desazapurine-derived), purine-derived and benzimidazole-derived moieties and their modifications, which could result in appearance of a number of biological activities. This includes [3+3] cyclocondensations, inverse electron-demand Diels-Alder reaction, intramolecular palladium-catalyzed arylation. 6-Nitro-, 6-amino-imidazo[4,5-b]pyridines, imidazo[4,5-b]pyridine-5-carboxylates were prepared from generated in situ 1-substituted-1H-5-aminoimidazoles and chromone-based precursors. Glycosilated purines and 1-desazapurines were obtained following so-called salvage nucleoside synthetic pathway. A number of fused imidazole-containing heterocycles were synthesized with usage of palladium-catalyzed C-C bond formation. In addition, unprecedented method of synthesis of 4-trifluoromethylpyridines was developed, including scope limitation and theoretical mechanistic studies with DFT methods.