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Item Dinuclear Copper Complexes of N-(2-Hydroxybenzylidene or 5-Bromo-2-hydroxybenzylidene)-4,6-O-ethylidene-β-D-glucopyranosylamine: Coordination Variation and Structural Diversity(CSJ, 2002) Sah, Ajay KumarDinuclear Cu(II) complexes of N-(2-hydroxybenzylidene or 5-bromo-2-hydroxybenzylidene)-4,6-O-ethylidene-β-D-glucopyranosylamine with coordination variation and molecular and lattice structural variations are explored.Item Amine mediated proton transfer reaction and C–Cl bond activation of solventchloroform by a trinuclear copper(ii) complex of a glucopyranosylamine derived ligand(RSC, 2006) Sah, Ajay KumarAn amine mediated C–Cl bond activation process of the solvent chloroform has been explored by a coordinatively labile trinuclear Cu(II) complex, [Cu3(L1)2(MeOH)(H2O)] (1), derived from N-(3-tert-butyl-2-hydroxybenzylidene)-4,6-O-ethylidene-β-D-glucopyranosylamine (H3L1). The effect of activation is extremely high with methylamine, resulting in the formation of [Cu(MeNH2)5]Cl2 (2) and [Cu(L2)2] (3; HL2 = 2-tert-butyl-6-[(methylimino)methyl]phenol), however, under identical conditions it is moderate with ethylamine resulting in the isolation of crystals of the intermediate amine bound trinuclear copper(II) complex, [Cu3(L1)2(EtNH2)2(MeOH)2] (5), which was further converted into the mononuclear complex, [Cu(HL1)(EtNH2)] (6), in a novel crystal-to-crystal transformation. The successive isolation of the ethylamine-bound tri- and mononuclear complexes, 5 and 6, supported the occurrence of proton transfer reactions, which might be a key step in C–Cl bond activation. The primary and secondary amines, 2-aminomethylpyridine, N,N′-dimethylethylenediamine, and 1,4,7-triazacyclononane, also having chelating features further enhance the rate of activation. No activation has been noted in the case of triethylamine and N,N,N′,N′-tetramethylethylenediamine. Formation of a carbene-trapped compound, 2,6-xylyl isocyanide, was confirmed in the reaction of complex 1 with 1,4,7-triazacyclononane and 2,6-xylidine in CHCl3, suggesting that the C–Cl bond cleavage led to the generation of dichlorocarbene. In addition, the mononuclear complex 6 has been transformed into a homotrinuclear complex [Cu3(L1)2(MeOH)2] by treatment with Cu(II) ions in MeOH/CHCl3, suggesting the possibility that the former could be regarded as a suitable metalloligand for heterotrimetallic complex synthesis.Item Saccharide derived dinuclear Cu(II) complex: An efficient catalyst for oxidation of catechol and benzylic alcohols(Elsiever, 2012-01) Sah, Ajay Kumar; Kumar, AnilCatalytical aspect of 4,6-O-ethylidene-β-D-glucopyranosylamine derived dinuclear Cu(II) complex has been explored. The complex exhibits good catecholase like activity and oxidizes model substrate 3,5-di-tert-butylcatechol to 3,5-di-tert-butyl-o-quinone. The complex also acts as selective catalyst to oxidize the primary and secondary alcohols to corresponding carbonyl compounds in excellent yield (65–82%) under mild conditions.Item Synthesis of cupric acetate selective receptor derived from alanyl glycoconjugate and their application in selective oxidation of benzylic alcohols(ACS, 2012-11) Sah, Ajay KumarCupric acetate sensing ability of alanyl-(4,6-O-ethylidene-β-D-glucopyranosylamine) derived receptor (L-N2O2) has been explored using fluorescence and UV–visible absorption spectroscopy. Cupric acetate quenches the fluorescence intensity of L-N2O2 with a correlation coefficient, R = 0.978 and Stern Volmer constant, KSV = 38,067 M− 1 revealing the possibilities of interaction via dynamic mode. Further, copper complex of L-N2O2 has been utilized in selective oxidation of primary and secondary alcohols into the corresponding carbonyl compounds.Item Selective Synthesis of Bis(indolyl)methanes Under Solvent Free Condition Using Glucopyranosylamine Derived cis-Dioxo Mo(VI) Complex as an Efficient Catalyst(Springer, 2015-11-07) Sah, Ajay Kumar; Kumar, Anilcis-Dioxomolybdenum(VI) complex of 4,6-O-ethylidene-β-d-glucopyranosylamine derived ligand has been used as an efficient catalyst in the selective synthesis of a series of bis(indolyl)methanes (BIMs) by condensing indole derivatives with carbonyl compounds. The adopted synthetic procedure is green in nature as solvent free reactions have been carried out using naturally occurring d-glucose derived ligands. Total 15 BIMs have been synthesised including four new ones, which have been characterized by mp, FTIR, NMR and mass spectroscopy. The catalyst has afforded good to excellent yield of BIMs in short reaction time and the former has been recycled five times without any significant loss in it’s catalytic efficiency.Item Synthesis, evaluation and molecular docking studies of amino acid derived N-glycoconjugates as antibacterial agents(Elsiever, 2015-12) Jha, Prabhat N.; Sah, Ajay Kumar; Murugesan, SankaranarayananSix amino acid derived N-glycoconjugates of d-glucose were synthesized, characterized and tested for antibacterial activity against G(+)ve (Bacillus cereus) as well as G(−)ve (Escherichia coli and Klebsiella pneumoniae) bacterial strains. All the tested compounds exhibited moderate to good antibacterial activity against these bacterial strains. The results were compared with the antibacterial activity of standard drug Chloramphenicol, where results of A5 (Tryptophan derived glycoconjugates) against E. coli and A4 (Isoleucine derived glycoconjugates) against K. pneumoniae bacterial strains are comparable with the standard drug molecule. In silico docking studies were also performed in order to understand the mode of action and binding interactions of these molecules. The docking studies revealed that, occupation of compound A5 at the ATP binding site of subunit GyrB (DNA gyrase, PDB ID: 3TTZ) via hydrophobic and hydrogen bonding interactions may be the reason for its significant in vitro antibacterial activity.