Browsing by Author "Kovalev, I.S."

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    Solvent-free synthesis of (poly)thiacalix[n]arenes: The evaluation of possible mechanism based on semi-preparative HPLC separation and mass-spectrometric investigation of the reaction products
    (Arkat, 2017) Kovalev, I.S.; Rahman, M.; Sadieva, L.K.; Pavlyuk, D.E.; Giri, K.; Santra, S.; Kopchuk, D.S.; Zyryanov, G.V.; Majee, A.; Chupakhin, O.N.; Charushin, V.N.
    The interaction between p-tert-butylphenol and elemental sulfur (S8) in alkaline condition in absence of solvent at 150-170 ?C have been studied. (Poly)thiacalix[n]arenes with the phenol units connected by bi- and trisulfide bridges have been detected and characterized based on the MS data. (Figure Presented). ?ARKAT USA, Inc.
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    Studies on the interactions of 5-R-3-(2-pyridyl)-1,2,4-triazines with arynes: inverse demand aza-Diels-Alder reaction versus aryne-mediated domino process
    (Royal Society of Chemistry, 2018) Kopchuk, D.S.; Nikonov, I.L.; Khasanov, A.F.; Giri, Koushiki.; Santra, S.; Kovalev, I.S.; Nosova, E.V.; Gundala, S.; Venkatapuram, P.; Zyryanov, G.V.; Majee, A.; Chupakhin, O.N.
    The interactions between substituted 5-R-3-(pyridyl-2)-1,2,4-triazines with in situ generated substituted aryne intermediates have been studied. The reaction afforded either inverse demand (ID) aza-Diels-Alder products or 1,2,4-triazine ring rearrangement (domino) products as major ones depending on the nature of both the substituents at the C5 position of the 1,2,4-triazine core or in the aryne moiety. The structures of the key products were confirmed based on X-ray data. Based on the density functional theoretical (DFT) studies of the Diels-Alder transition state geometries, the influence of the nature of arynes on the direction of the 1,2,4-triazine transformation has been proposed.