Publications by authors named "V V Syakaev"
A novel HSO-catalyzed ANRORC-type rearrangement of pyrazinones to imidazoles proceeding through pyridazino[]annulation with simultaneous introduction of a pyrazole ring at position 2 of the imidazole system has been developed, which offers efficient and expedited access to new biheterocyclic systems - 2-(pyrazol-3-ul)imidazoles and 2-(pyrazol-3-yl)imidazo[4,5-]pyridazines. Diverse bi--heterocyclic systems with the imidazo[4,5-]pyridazine-4,7-diamine moiety could be obtained in excellent yield when 5,6-dicyano-3-(2-oxo-2-ethyl)pyrazin-2(1)-ones interact with hydrazines the selective spiro-formation in a tandem ring-opening/ring-closing process, which allowed the simultaneous construction of five new C-N bonds. This new method is compatible with an array of functional groups, proceeds under mild reaction conditions with the involvement of commercially available reagents.
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- A new method was developed for synthesizing 2-(quinolin-4-yl)-1,4-dihydroquinazoline compounds through the rearrangement of spiro[benzo[][1,4]diazepine-3,4'-quinolin]-2(1)-ones.
- Attempts to create isomeric 2-(2-aminophenyl)-5-benzo[][1,4]diazepin-3(4)-one resulted in an unexpected transformation, leading to a novel compound called 6-methyl-8,13-dihydro-13a-quinazolino[4,3-]quinazolin-5-ium 13a-carboxylate.
- The hydrolysis of
The electrophilic activation of various substrates via double or even triple protonation in superacidic media enables reactions with extremely weak nucleophiles. Despite the significant progress in this area, the utility of organophosphorus compounds as superelectrophiles still remains limited. Additionally, the most common superacids require a special care due to their high toxicity, exceptional corrosiveness and moisture sensitivity.
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- A new method was created to easily convert spiro[indoline-3,2'-quinoxaline]-2,3'-diones into quinolino[3,4-]quinoxalin-6-ones, using isatines, malononitrile, and 1,2-phenylenediamines under mild conditions.
- This method is efficient and yields high amounts of the desired compounds, making it useful for creating a diverse range of quinolino[3,4-]quinoxalin-6-ones that could be tested in medicinal chemistry.
- The researchers also used extensive DFT calculations to study the reaction mechanism in detail.
Herein, we report a polyphosphoric acid (PPA)-mediated divergent metal-free operation to access a diverse collection of 3-(indol-2-yl)quinoxalin-2-ones and 4-(benzimidazol-2-yl)-3-methylcinnolines in moderate to excellent overall yields. The described process involves two distinct, and competing rearrangements of 3-(methyl(2-phenylhydrazono)methyl)quinoxalin-2-ones, namely [3,3]-sigmatropic Fischer rearrangement with the formation of an indole ring to produce 3-(indol-2-yl)-quinoxalin-2-ones, and Mamedov rearrangement with simultaneous construction of benzimidazole and cinnoline rings to form the new biheterocyclic system─4-(benzimidazol-2-yl)-3-methylcinnolines. The reaction mechanism of both rearrangement channels is explored by extensive dispersion-corrected DFT calculations.
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