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A R Burilov - One of the best experts on this subject based on the ideXlab platform.

  • photophysical properties of new anthracene ended calix 4 Resorcinols
    Mendeleev Communications, 2020
    Co-Authors: I R Knyazeva, Victor V Syakaev, Tatiana P Gerasimova, I E Kolesnikov, Sergey A Katsyuba, A R Burilov
    Abstract:

    New calix[4]Resorcinols with four anthracene-ended triazolecontaining fragments as rctt- and rccc-diastereoisomers were obtained in two synthetic pathways, namely, by acidcatalyzed condensation of Resorcinols with 4-{[1-(anthracen-9-ylmethyl)-1H-[1,2,3]triazol-4-yl]methoxy}benzaldehyde or by the click reaction of 9-(azidomethyl)anthracene with calix[4]Resorcinols bearing four terminal acetylene moieties. The compounds obtained demonstrate dual emission in solid state with intensity of low energy band depending on calix[4]resorcinol conformation. The emission in solutions is dominated by anthracene bands, with rccc-isomer showing additional low energy band.

  • synthesis and structure of new chlorine containing calix 4 Resorcinols
    Mendeleev Communications, 2019
    Co-Authors: I R Knyazeva, Victor V Syakaev, O A Lodochnikova, A R Burilov
    Abstract:

    New calix[4]Resorcinols containing four organochlorine moieties have been synthesized in high yields via one-step condensation of resorcinol, 2-methylresorcinol or pyrogallol with 4′-formylphenyl 4-(chloromethyl)benzoate. It has been found that the diastereomeric ratio of the products depends substantially on the starting polyphenol. The rctt- and/or rccc-diastereomers have been isolated and their structure and composition have been determined by 1H, 13C NMR and IR spectroscopy, MALDI mass spectrometry and elemental analysis, the crystal structure of one rctt-product has been established by single crystal X-ray diffraction.

  • synthesis of rccc and rctt diastereoisomers of novel triazole containing calix 4 Resorcinols
    Tetrahedron Letters, 2018
    Co-Authors: Irina R. Knyazeva, Victor V Syakaev, Wolf D Habicher, Karina M Mukhamedyanova, A T Gubaidullin, A R Burilov
    Abstract:

    Abstract Novel calix[4]Resorcinols containing four triazole fragments on the aromatic substituents of the calixarene framework were synthesized via a one-step condensation of resorcinol and its derivatives with 4-(1-benzyl-1 H -[1,2,3]triazol-4-ylmethoxy)benzaldehyde. The macrocyclic products are rctt - and/or rccc -isomers, which were isolated and characterized by NMR and single crystal X-ray diffraction studies. The same products were also prepared via the click -reaction of benzyl azide with previously synthesized calix[4]Resorcinols containing four alkyne terminal groups on the aromatic substituents. In this case, only rctt -diastereomers of the corresponding calixarenes were isolated, which is governed by conformational features of the starting macrocycles.

  • synthesis of novel highly functionalized triazole linked calix 4 Resorcinols via click reaction
    Mendeleev Communications, 2017
    Co-Authors: I R Knyazeva, A R Burilov, Victor V Syakaev, Wolf D Habicher, Dilara K Abdrafikova, Karina M Mukhamedyanova, Bulat Gabidullin, A T Gubaidullin, Michail A Pudovik
    Abstract:

    A single-step acid-catalyzed condensation of resorcinol or 2-methylresorcinol with 4-(prop-2-yn-1-yloxy)benzaldehyde stereoselectively gives exclusively rctt-isomers of new calix[4]- Resorcinols in chair conformation bearing four terminal alkyne groups at aromatic substituents. Further alkylation of free hydroxy groups with propargyl bromide affords new calix[4]- Resorcinols containing 12 terminal alkyne groups. Subsequent click reaction of these compounds with benzyl azide results in highly functionalized calix[4]Resorcinols with 12 triazole- linked branches.

  • novel calix 4 Resorcinols with sulfamide fragments in the lower rim
    Russian Journal of General Chemistry, 2017
    Co-Authors: A V Smolobochkin, A S Gazizov, A R Burilov, Ekaterina A Anikina, M. A. Pudovik
    Abstract:

    Novel calix[4]Resorcinols modified by sulfamide fragments were synthesized via acid-catalyzed opening of the pyrrolidine ring in 1-sulfonyl-2-naphthylpyrrolidines in the presence of pyrogallol. A possibility of synthesis of calix[4]resorsinols without isolation of the intermediate naphthalene-2-ylpyrrolidines was demonstrated.

Hiroaki Sasai - One of the best experts on this subject based on the ideXlab platform.

  • chiral dinuclear vanadium complex mediated oxidative coupling of Resorcinols
    Journal of Organic Chemistry, 2019
    Co-Authors: Makoto Sako, Takanori Aoki, Nadine Zumbragel, Lukas Schober, Harald Groger, Shinobu Takizawa, Hiroaki Sasai
    Abstract:

    A method for the highly regio- and enantioselective oxidative coupling of Resorcinols has been established by using dibrominated dinuclear vanadium(V) catalyst 1c under air. When Resorcinols bearing an aryl substituent were applied as substrates to the coupling, axially chiral biResorcinols were obtained as single regioisomers in high yield with up to 98% ee.

  • Chiral Dinuclear Vanadium Complex-Mediated Oxidative Coupling of Resorcinols
    2018
    Co-Authors: Makoto Sako, Takanori Aoki, Lukas Schober, Shinobu Takizawa, Nadine Zumbrägel, Harald Gröger, Hiroaki Sasai
    Abstract:

    A method for the highly regio- and enantioselective oxidative coupling of Resorcinols has been established by using dibrominated dinuclear vanadium­(V) catalyst 1c under air. When Resorcinols bearing an aryl substituent were applied as substrates to the coupling, axially chiral biResorcinols were obtained as single regioisomers in high yield with up to 98% ee

M. A. Pudovik - One of the best experts on this subject based on the ideXlab platform.

Bodo Philipp - One of the best experts on this subject based on the ideXlab platform.

  • heterologous expression and identification of the genes involved in anaerobic degradation of 1 3 dihydroxybenzene resorcinol in azoarcus anaerobius
    Journal of Bacteriology, 2007
    Co-Authors: Paula I Darley, Bernhard Schink, Jutta A Hellstern, Javier I Medinabellver, Silvia Marques, Bodo Philipp
    Abstract:

    Azoarcus anaerobius, a strictly anaerobic, gram-negative bacterium, utilizes resorcinol as a sole carbon and energy source with nitrate as an electron acceptor. Previously, we showed that resorcinol degradation by this bacterium is initiated by two oxidative steps, both catalyzed by membrane-associated enzymes that lead to the formation of hydroxyhydroquinone (HHQ; 1,2,4-benzenetriol) and 2-hydroxy-1,4-benzoquinone (HBQ). This study presents evidence for the further degradation of HBQ in cell extracts to form acetic and malic acids. To identify the A. anaerobius genes required for anaerobic resorcinol catabolism, a cosmid library with genomic DNA was constructed and transformed into the phylogenetically related species Thauera aromatica, which cannot grow with resorcinol. By heterologous complementation, a transconjugant was identified that gained the ability to metabolize resorcinol. Its cosmid, designated R, carries a 29.88-kb chromosomal DNA fragment containing 22 putative genes. In cell extracts of T. aromatica transconjugants, resorcinol was degraded to HHQ, HBQ, and acetate, suggesting that cosmid R carried all of the genes necessary for resorcinol degradation. On the basis of the physiological characterization of T. aromatica transconjugants carrying transposon insertions in different genes of cosmid R, eight open reading frames were found to be essential for resorcinol mineralization. Resorcinol hydroxylase-encoding genes were assigned on the basis of sequence analysis and enzyme assays with two mutants. Putative genes for hydroxyhydroquinone dehydrogenase and enzymes involved in ring fission have also been proposed. This work provides the first example of the identification of genes involved in the anaerobic degradation of aromatic compounds by heterologous expression of a cosmid library in a phylogenetically related organism.

  • Evidence of Two Oxidative Reaction Steps Initiating Anaerobic Degradation of Resorcinol (1,3-Dihydroxybenzene) by the Denitrifying Bacterium Azoarcus anaerobius
    Journal of bacteriology, 1998
    Co-Authors: Bodo Philipp, Bernhard Schink
    Abstract:

    The denitrifying bacterium Azoarcus anaerobius LuFRes1 grows anaerobically with resorcinol (1,3-dihydroxybenzene) as the sole source of carbon and energy. The anaerobic degradation of this compound was investigated in cell extracts. Resorcinol reductase, the key enzyme for resorcinol catabolism in fermenting bacteria, was not present in this organism. Instead, resorcinol was hydroxylated to hydroxyhydroquinone (HHQ; 1,2,4-trihydroxybenzene) with nitrate or K3Fe(CN)6 as the electron acceptor. HHQ was further oxidized with nitrate to 2-hydroxy-1,4-benzoquinone as identified by high-pressure liquid chromatography, UV/visible light spectroscopy, and mass spectroscopy. Average specific activities were 60 mU mg of protein−1 for resorcinol hydroxylation and 150 mU mg of protein−1 for HHQ dehydrogenation. Both activities were found nearly exclusively in the membrane fraction and were only barely detectable in extracts of cells grown with benzoate, indicating that both reactions were specific for resorcinol degradation. These findings suggest a new strategy of anaerobic degradation of aromatic compounds involving oxidative steps for destabilization of the aromatic ring, different from the reductive dearomatization mechanisms described so far.

Lukas Schober - One of the best experts on this subject based on the ideXlab platform.

  • chiral dinuclear vanadium complex mediated oxidative coupling of Resorcinols
    Journal of Organic Chemistry, 2019
    Co-Authors: Makoto Sako, Takanori Aoki, Nadine Zumbragel, Lukas Schober, Harald Groger, Shinobu Takizawa, Hiroaki Sasai
    Abstract:

    A method for the highly regio- and enantioselective oxidative coupling of Resorcinols has been established by using dibrominated dinuclear vanadium(V) catalyst 1c under air. When Resorcinols bearing an aryl substituent were applied as substrates to the coupling, axially chiral biResorcinols were obtained as single regioisomers in high yield with up to 98% ee.

  • Chiral Dinuclear Vanadium Complex-Mediated Oxidative Coupling of Resorcinols
    2018
    Co-Authors: Makoto Sako, Takanori Aoki, Lukas Schober, Shinobu Takizawa, Nadine Zumbrägel, Harald Gröger, Hiroaki Sasai
    Abstract:

    A method for the highly regio- and enantioselective oxidative coupling of Resorcinols has been established by using dibrominated dinuclear vanadium­(V) catalyst 1c under air. When Resorcinols bearing an aryl substituent were applied as substrates to the coupling, axially chiral biResorcinols were obtained as single regioisomers in high yield with up to 98% ee