The Friedel–Crafts reaction of novel 3,5-diarylsubstituted 5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones... more The Friedel–Crafts reaction of novel 3,5-diarylsubstituted 5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones was used for low cost, one-pot preparation of polycyclic indole derivatives structurally similar to Ergot alkaloids.
A straightforward three-step procedure affording a wide range of novel 7-aryl substituted paullon... more A straightforward three-step procedure affording a wide range of novel 7-aryl substituted paullone derivatives was developed. This scaffold is structurally similar to 2-(1H-indol-3-yl)acetamides—promising antitumor agents—hence, could be useful for the development of a new class of anticancer drugs.
Microwave-assisted reaction between 2-(3-oxoindolin-2-yl)-2-phenylacetonitriles andbenzene-1,2-di... more Microwave-assisted reaction between 2-(3-oxoindolin-2-yl)-2-phenylacetonitriles andbenzene-1,2-diamines leads to the high-yielding formation of the corresponding quinoxalines as sole, easily isolaable products. The featured transformation involves unusual extrusion of phenylacetonitrile molecule and could be performed in a short sequence starting from commonly available indoles and nitroolefins.
A highly efficient and expeditious one-pot approach towards 2-(3-oxoindolin-2-yl)acetonitriles wa... more A highly efficient and expeditious one-pot approach towards 2-(3-oxoindolin-2-yl)acetonitriles was designed, which involves a base-assisted aldol reaction of ortho-nitroacetophenones, followed by hydrocyanation, triggering an unusual reductive cyclization reaction.
3-(1H-Indol-3-yl)benzofuran-2(3H)-ones were efficiently accessed via polyphosphoric acid-mediated... more 3-(1H-Indol-3-yl)benzofuran-2(3H)-ones were efficiently accessed via polyphosphoric acid-mediated condensation of 3-(2-nitrovinyl)-1H-indoles with phenols.
Heterocycles prepared via [3 + 2]-cycloaddition of pyridinium ylides to 1-chloro-2-nitrostyrenes ... more Heterocycles prepared via [3 + 2]-cycloaddition of pyridinium ylides to 1-chloro-2-nitrostyrenes were evaluated as microtubule-targeting anticancer agents potent against BE(2)-C neuroblastoma cells.
2-Aryl-2-(3-indolyl)acetohydroxamic acids demonstrate promising antitumor activity, but quickly m... more 2-Aryl-2-(3-indolyl)acetohydroxamic acids demonstrate promising antitumor activity, but quickly metabolize in vivo via glucuronidation of hydroxamic acid residue. In an attempt to improve their pharmacokinetics, methyl esters were synthesized via a newly developed protocol for chemoselective mono-methylation of hydroxamic acids. The cytotoxicity of these derivatives against the HeLa cell line was evaluated and found to be inferior compared to the parent lead compounds.
1H-Cyclopenta[cd]phenalenes 2 are interesting polycyclic aromatic architectures that can be viewe... more 1H-Cyclopenta[cd]phenalenes 2 are interesting polycyclic aromatic architectures that can be viewed as derivatives of the acenaphthene system peri-anneleated by a benzene ring. These compounds attract the attention of chemists and material scientists due to being the smallest structural units modeling the orbital and physico-chemical properties of fullerenes and defected carbon nanotubes. Along with pyrene (1) derivatives, such compounds could be used as uorescent probes and lightsensing units in various biochemical assays. However, due to a very low solubility in water and signicant carcinogenicity, the potential of these structural fragments for cytological and in vivo applications could be limited. We pondered if this issue can be addressed by partial replacement of carbon with nitrogen atoms to afford aromatic polyheterocyclic scaffolds with improved solubility, which also are expected to showmuch lower metabolitic stability. We previously demonstrated several synthetic approac...
Department of Chemistry, North Caucas Stavropol 355009, Russian Federation. E-m Department of Org... more Department of Chemistry, North Caucas Stavropol 355009, Russian Federation. E-m Department of Organic Chemistry, People' University), 6 Miklukho-Maklaya St., Mosco Department of Chemistry, University of Kan 66045-7582, USA. E-mail: mrubin@ku.edu; 5071 † Electronic supplementary informati crystallographic data. CCDC 1544322. Fo or other electronic format see DOI: 10.103 Cite this: RSC Adv., 2017, 7, 29927
Imidazo[1,5-a]pyridines were efficiently prepared via the cyclization of 2-picolylamines with nit... more Imidazo[1,5-a]pyridines were efficiently prepared via the cyclization of 2-picolylamines with nitroalkanes electrophilically activated in the presence of phosphorous acid in polyphosphoric acid (PPA) medium.
Electrophilically activated nitroalkanes play a dual role in the novel reaction with diaminoperim... more Electrophilically activated nitroalkanes play a dual role in the novel reaction with diaminoperimidines, promoting their oxidative peri-annulation to access tetraazapyrenes.
A highly efficient one-pot method for the reductive coupling of indoles to nitrostyrenes in PPA d... more A highly efficient one-pot method for the reductive coupling of indoles to nitrostyrenes in PPA doped with PCl3was developed. This method allows direct access to primary (indol-3-yl)acetamides, interesting as anti-cancer drug candidates.
PPA-activated nitroalkanes are employed in the design of a one-pot cascade transformation involvi... more PPA-activated nitroalkanes are employed in the design of a one-pot cascade transformation involvingortho-C–H functionalization, by Beckman rearrangement, and condensation to produce benzoxazoles and benzobisoxazoles directly from phenols.
The mechanistic rationale involving activation of nitroalkanes towards interaction with nucleophi... more The mechanistic rationale involving activation of nitroalkanes towards interaction with nucleophilic reagents in the presence of polyphosphoric acid (PPA) was re-evaluated. Could nitrile oxide moieties be formed during this process?
The recently discovered [4+1]-spirocyclization of nitroalkenes to indoles provided a convenient n... more The recently discovered [4+1]-spirocyclization of nitroalkenes to indoles provided a convenient new approach to 2-(1H-indol-2-yl)acetonitriles. However, this reaction was complicated by the formation of inert 3-(2-nitroethyl)-1H-indole byproducts. Herein, we offer a workaround this problem that allows for effective transformation of the unwanted byproducts into acetonitrile target molecules.
One-pot procedure combining conjugate addition of Grignard reagents to (2-nitroalkenyl)indoles an... more One-pot procedure combining conjugate addition of Grignard reagents to (2-nitroalkenyl)indoles and subsequent acid-assisted spirocyclization allowed for diastereoselective preparation of 4′H-spiro[indole-3,5′-isoxazoles].
The Friedel–Crafts reaction of novel 3,5-diarylsubstituted 5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones... more The Friedel–Crafts reaction of novel 3,5-diarylsubstituted 5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones was used for low cost, one-pot preparation of polycyclic indole derivatives structurally similar to Ergot alkaloids.
A straightforward three-step procedure affording a wide range of novel 7-aryl substituted paullon... more A straightforward three-step procedure affording a wide range of novel 7-aryl substituted paullone derivatives was developed. This scaffold is structurally similar to 2-(1H-indol-3-yl)acetamides—promising antitumor agents—hence, could be useful for the development of a new class of anticancer drugs.
Microwave-assisted reaction between 2-(3-oxoindolin-2-yl)-2-phenylacetonitriles andbenzene-1,2-di... more Microwave-assisted reaction between 2-(3-oxoindolin-2-yl)-2-phenylacetonitriles andbenzene-1,2-diamines leads to the high-yielding formation of the corresponding quinoxalines as sole, easily isolaable products. The featured transformation involves unusual extrusion of phenylacetonitrile molecule and could be performed in a short sequence starting from commonly available indoles and nitroolefins.
A highly efficient and expeditious one-pot approach towards 2-(3-oxoindolin-2-yl)acetonitriles wa... more A highly efficient and expeditious one-pot approach towards 2-(3-oxoindolin-2-yl)acetonitriles was designed, which involves a base-assisted aldol reaction of ortho-nitroacetophenones, followed by hydrocyanation, triggering an unusual reductive cyclization reaction.
3-(1H-Indol-3-yl)benzofuran-2(3H)-ones were efficiently accessed via polyphosphoric acid-mediated... more 3-(1H-Indol-3-yl)benzofuran-2(3H)-ones were efficiently accessed via polyphosphoric acid-mediated condensation of 3-(2-nitrovinyl)-1H-indoles with phenols.
Heterocycles prepared via [3 + 2]-cycloaddition of pyridinium ylides to 1-chloro-2-nitrostyrenes ... more Heterocycles prepared via [3 + 2]-cycloaddition of pyridinium ylides to 1-chloro-2-nitrostyrenes were evaluated as microtubule-targeting anticancer agents potent against BE(2)-C neuroblastoma cells.
2-Aryl-2-(3-indolyl)acetohydroxamic acids demonstrate promising antitumor activity, but quickly m... more 2-Aryl-2-(3-indolyl)acetohydroxamic acids demonstrate promising antitumor activity, but quickly metabolize in vivo via glucuronidation of hydroxamic acid residue. In an attempt to improve their pharmacokinetics, methyl esters were synthesized via a newly developed protocol for chemoselective mono-methylation of hydroxamic acids. The cytotoxicity of these derivatives against the HeLa cell line was evaluated and found to be inferior compared to the parent lead compounds.
1H-Cyclopenta[cd]phenalenes 2 are interesting polycyclic aromatic architectures that can be viewe... more 1H-Cyclopenta[cd]phenalenes 2 are interesting polycyclic aromatic architectures that can be viewed as derivatives of the acenaphthene system peri-anneleated by a benzene ring. These compounds attract the attention of chemists and material scientists due to being the smallest structural units modeling the orbital and physico-chemical properties of fullerenes and defected carbon nanotubes. Along with pyrene (1) derivatives, such compounds could be used as uorescent probes and lightsensing units in various biochemical assays. However, due to a very low solubility in water and signicant carcinogenicity, the potential of these structural fragments for cytological and in vivo applications could be limited. We pondered if this issue can be addressed by partial replacement of carbon with nitrogen atoms to afford aromatic polyheterocyclic scaffolds with improved solubility, which also are expected to showmuch lower metabolitic stability. We previously demonstrated several synthetic approac...
Department of Chemistry, North Caucas Stavropol 355009, Russian Federation. E-m Department of Org... more Department of Chemistry, North Caucas Stavropol 355009, Russian Federation. E-m Department of Organic Chemistry, People' University), 6 Miklukho-Maklaya St., Mosco Department of Chemistry, University of Kan 66045-7582, USA. E-mail: mrubin@ku.edu; 5071 † Electronic supplementary informati crystallographic data. CCDC 1544322. Fo or other electronic format see DOI: 10.103 Cite this: RSC Adv., 2017, 7, 29927
Imidazo[1,5-a]pyridines were efficiently prepared via the cyclization of 2-picolylamines with nit... more Imidazo[1,5-a]pyridines were efficiently prepared via the cyclization of 2-picolylamines with nitroalkanes electrophilically activated in the presence of phosphorous acid in polyphosphoric acid (PPA) medium.
Electrophilically activated nitroalkanes play a dual role in the novel reaction with diaminoperim... more Electrophilically activated nitroalkanes play a dual role in the novel reaction with diaminoperimidines, promoting their oxidative peri-annulation to access tetraazapyrenes.
A highly efficient one-pot method for the reductive coupling of indoles to nitrostyrenes in PPA d... more A highly efficient one-pot method for the reductive coupling of indoles to nitrostyrenes in PPA doped with PCl3was developed. This method allows direct access to primary (indol-3-yl)acetamides, interesting as anti-cancer drug candidates.
PPA-activated nitroalkanes are employed in the design of a one-pot cascade transformation involvi... more PPA-activated nitroalkanes are employed in the design of a one-pot cascade transformation involvingortho-C–H functionalization, by Beckman rearrangement, and condensation to produce benzoxazoles and benzobisoxazoles directly from phenols.
The mechanistic rationale involving activation of nitroalkanes towards interaction with nucleophi... more The mechanistic rationale involving activation of nitroalkanes towards interaction with nucleophilic reagents in the presence of polyphosphoric acid (PPA) was re-evaluated. Could nitrile oxide moieties be formed during this process?
The recently discovered [4+1]-spirocyclization of nitroalkenes to indoles provided a convenient n... more The recently discovered [4+1]-spirocyclization of nitroalkenes to indoles provided a convenient new approach to 2-(1H-indol-2-yl)acetonitriles. However, this reaction was complicated by the formation of inert 3-(2-nitroethyl)-1H-indole byproducts. Herein, we offer a workaround this problem that allows for effective transformation of the unwanted byproducts into acetonitrile target molecules.
One-pot procedure combining conjugate addition of Grignard reagents to (2-nitroalkenyl)indoles an... more One-pot procedure combining conjugate addition of Grignard reagents to (2-nitroalkenyl)indoles and subsequent acid-assisted spirocyclization allowed for diastereoselective preparation of 4′H-spiro[indole-3,5′-isoxazoles].
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