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    Microwave-assisted and conventional synthesis and stereogenic properties of monospirocyclotriphosphazene derivatives
    (Pergamon-Elsevier Science Ltd, 2010) Işıklan, Muhammet; Sonkaya, Ömer; Çoşut, Bünyemin; Yeşilot, Serkan; Hökelek, Tuncer
    The reactions of hexachlorocyclotriphosphazene, N3P3Cl6, with N/O donor type N-alkyl or (aryl)-o-hydroxybenzylamines HO(C6H4)CH2NHR(Ar), [R(Ar) = C(CH3)(3) (1), Ph (2)] produce monospirocyclic tetra-chlorocyclotriphosphazenes (1a and 2a). The geminal substituted cyclotriphosphazenes (1b, 1d, 2b and 2d) are obtained from the reactions of 1 equiv. of la and 2a with 2 equiv. of pyrrolidine or morpholine in THF, while the fully substituted phosphazenes (1c, 1e, 2c and 2e) are formed from the reactions of 1a and 2a with the excess pyrrolidine or morpholine in toluene, between 24 and 48 h. The microwave-assisted reactions of la and 2a with excess pyrrolidine or morpholine in toluene afford the fully substituted products with higher yields than those which were obtained by conventional methods. The structural investigations of the compounds have been verified by elemental analyses, ESI-MS, FTIR, H-1, C-13, P-31 NMR and HETCOR techniques. The crystal structure of 2a is determined by X-ray crystallography and the phosphazene ring is in the flattened boat form. Compounds 1b, 1d, 2b and 2d in which the spiro aryloxy moiety provides the one centre of chirality exist as racemates and the chirality has been confirmed by P-31 NMR spectroscopy on addition of a chiral solvating agent (CSA), (S)-(+)-2,2,2-tri-fluoro-1-(9'-anthryl)ethanol. (C) 2010 Elsevier Ltd. All rights reserved.
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    Öğe
    Phosphorus-Nitrogen Compounds. 21. Syntheses, Structural Investigations, Biological Activities, and DNA Interactions of New N/O Spirocyclic Phosphazene Derivatives. The NMR Behaviors of Chiral Phosphazenes with Stereogenic Centers upon the Addition of Chiral Solvating Agents
    (Amer Chemical Soc, 2010) Işıklan, Muhammet; Asmafiliz, Nuran; Özalp, Ezgi Elif; İlter, Elif Ece; Kılıç, Zeynel; Çoşut, Bünyemin; Akyüz, Emel
    The reactions of hexachlorocyclotriphosphazatriene, N3P3Cl6, with N/O-donor-type N-alkyl (or aryl)-o-hydroxybenzylamines (la-le) produce mono- (2a-2e), di- (3a-3d), and tri- (4a and 4b) spirocyclic phosphazenes. The tetrapyrrolidino monospirocyclic phosphazenes (2f-2i) are prepared from the reactions of partly substituted compounds (2a-2d) with excess pyrrolidine. The dispirodipyrrolidinophosphazenes (3e-3h) and trispirophosphazenes (3i-3k) are obtained from the reactions of trans-dispirophosphazenes with excess pyrrolidine and sodium (3-amino-1-propanoxide), respectively. Compounds 3a-3d have cis and trans geometric isomers. Only the trans isomers of these compounds are isolated. Compounds 3a-3h have two stereogenic P atoms. They are expected to be in cis (meso) and trans (racemic) geometric isomers. In the trans trispiro compounds (3i-3k), there are three stereogenic P atoms. They are expected to be in racemic mixtures. The stereogenic properties of 3a-3k are confirmed by P-31 NMR spectroscopy upon the addition of the chiral solvating agent; (S)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol. The molecular structures of 3i-3k, 4a, and 4b look similar to a propeller, where the chemical environment of one P atom is different from that of others. Additionally, 4a and 4b are also expected to exist as cis-trans-trans and cis-cis-cis geometric isomers, but both of them are found to be in cis-trans-trans geometries. The solid-state structures of 2a, 2e, 2f, 3e, and 31 are determined by X-ray crystallography. The compounds 2f-2i, 3e-3i, and 3k are screened for antibacterial activity against Gram-positive and Gram-negative bacteria and for antifungal activity against yeast strains. These compounds (except 3f) have shown a strong affinity against most of the bacteria. Minimum inhibitory concentrations (MIC) are determined for 2f-2i, 3e-3i, and 3k. DNA binding and the nature of interaction with pUC18 plasmid DNA are studied. The compounds 2f-2i, 3e-3i, and 3k induce changes on the DNA mobility. The prevention of BamHI and HindIII digestion (except 2g) with compounds indicates that the compounds bind with nucleotides in DNA.