Browsing by Author "Majee, A."

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Azaanthracenes via Inverse Electron-Demand Diels–Alder Reaction
(THIEME STUTTGART, 2016) Kopchuk, Dmitry S.; Chepchugov, N. V.; Taniya, Olga S.; Khasanov, A.F.; Giri,Kousik; Kovalev, Igor S.; Santra, S.; Zyryanov, Grigory V.; Majee, A.; Rusinov, V.L.; Chupakhin, O.N.
Significance: Azaanthracenes are important fluo- Comment: The benzyne derivative is generated in rophores that are used in a number of applications such as metal or pH sensors. In this report the authors describe a new synthesis of this type of structure via an inverse electron-demand aza- Diels–Alder reaction between a benzyne derivative and an electron-deficient triazine. situ from the diazotization of 2-amino-3-naphthoic acid. It was found that the cyano activating group at the 5-position of the triazine is crucial for the reaction to take place because it offers a smaller energy difference between the cycloaddition HOMO and LUMO.
CuO Nanoparticles as a Simple and Efficient Green Catalyst for the Aziridine Ring-Opening: Examination of a Broad Range of Nucleophiles
(Wiley-Blackwell, 2020) Chatterjee, R; Santra, S; Chakraborty, Ghosal N; Giri, K; Zyryanov, G.V; Majee, A.
It has been observed that CuO nanoparticles act as effective and reusable catalyst for the ring-opening reaction of aziridines with a wide range of nucleophiles such as alcohols, thiols, and indoles. The catalytic activity has been tested in large scale reactions. The methodology is applicable in very low catalyst loading. The reaction proceeds under solvent-free conditions. The catalyst has been used for six consecutive cycles with comparable efficiency. The present methodology could be considered as environmentally benign as indicated by the calculation of E-factors which are very low in the range of 0.37-1.31. - 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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.
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.