- Synthesis of 2,6-Diformyl-3-hydroxypyridine Bis: A Pentadentate N,N,N,N,N Ligand for the Preparation of Chelating Resins
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The synthesis of 2,6-diformyl-3-hydroxypyridine bis as a versatile intermediate with a reactive hydroxyl group, which can be bonded to lipophilic chains and/or to polymeric supports, is reported.
- Baldo, Maria Antonietta,Chessa, Gavino,Marangoni, Giampaolo,Pitteri, Bruno
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- Pyriporphyrinone: A new 18-π aromatic porphyrinoid
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A pyriphorphyrinone was synthesized by cyclocondensation of tripyrrane 2 with 2,6-diformyl-3-hydroxypyridine (1b). It was possible to identify 3b as the exclusively formed tautomer.
- Sch?nemeier, Thomas,Breitmaier, Eberhard
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- Hydroxyl group effect in novel NNN type pyridine based ruthenium (II) complex for the transfer hydrogenation of ketones
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The new NNN type pyridine ligands were prepared by using low cost and readily available starting materials and metalated with RuCl2(PPh3)3 to obtain ruthenium(II) complexes. All structures were illuminated by NMR, HRMS, and FT-IR spectroscopy. The complexes exhibited good catalytic activity in transfer hydrogen reaction of ketones and it was found that a hydroxyl group on β-position of the pyridine ring had a dramatic effect on the catalyst efficiency.
- Sahin, Irfan,Emir, Sedat,Ispir, Esin,Karakaya, Idris,Gumus, Selcuk,Ulusoy, Mahmut,Karabuga, Semistan
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- Recoverable polymer-bound homogeneous catalysts for catalytic chain transfer process
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Disclosed herein are novel polymer-tethered ligands, metal complexes comprising these ligands, and the use of these complexes as chain transfer catalysts to control the molecular weight of oligomeric and polymeric materials produced in a radical polymerization process. The materials made by the processes disclosed herein have significantly reduced color, making them suitable for a wide range of color-critical end-uses, including automotive coatings.
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- Macrocyclic complexes of yttrium, the lanthanides and the actinides having peripheral coupling functionalities
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Symmetrically di-functionalized water soluble macrocyclic complexes of lanthanide, actinide and yttrium ions were obtained by metal templated, Schiff-base, cyclic condensation of: (1) a functionalized 1,2-diaminoethane and a dicarbonyl compound selected from the group consisting of 2,6-dicarbonylpyridine, 2,6-diformylpyridine, 2,5-dicarbonylfuran, 2,5-diformylfuran, 2,5-dicarbonyl-thiophene and 2,5-diformylthiophene; or (2) 1,2-diaminoethane and a ring-substituted heterocyclic dicarbonyl compound selected from a group consisting of substituted 2,6-dicarbonylpyridine, substituted 2,6-diformylpyridine, substituted 2,5-dicarbonylfuran, substituted 2,5-diformylfuran; substituted 2,5-dicarbonyl thiophene, and substituted 2,5-diformylthiophene. Asymmetrically functionalized water soluble macrocyclic complexes of the lanthanide, actinide and yttrium ions were obtained by metal templated, Schiff-base, cyclic condensation of appropriately substituted diamine and dicarbonyl precursors, with such precursors contributing two heteroaromatic moieties (pyridine, furan, thiophene, or a combination thereof) to the resulting macrocyclic structure. The coordination complexes thus formed are kinetically stable in dilute aqueous solution. They are further reacted, or coupled, through a substituent on the 1,2-diaminoethane or on the pyridine, furan, or thiophene moieties, to one of the following: proteinaceous materials, polysaccharides, polynucleotides, other biologically compatible macromolecules or bridging molecules which, can be further reacted or coupled to the above mentioned substrates. These macrocyclic complexes are suitable in the preparation of reporter molecules and for magnetic resonance, radiation imaging and radiation therapy.
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- Oxypyriporphyrin, the First Fully Aromatic Porphyrinoid Macrocycle with a Pyridine Subunit
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The synthesis of the first example of an aromatic pyridine-containing porphyrinoid 10 has been accomplished in excellent yields by the acid-cataalyzed "3+1" condensation of 3-hydroxypyridinedicarboxaldehyde (8) with tripyrrane 9.The key intermediate 8 was obtained by the selenium dioxide oxidation of the known biscarbinol 7.The aromaticity of "oxypyriporphyrin" 10 has been confirmed by MS, NMR, IR, and UV/Vis spectroscopy.This system afforded a monocation in 0.2percent TFA-chloroform, and a dication was observed in 2percent TFA-chloroform; these species also retained macrocyclic aromaticity.Oxypyriporphyrin readilly formed the corresponding metal chelates 14a-c by reaction with zinc, copper(II), or nickel(II) acetate, and this observation suggest that there are extensive possibilities for the use of 10 in coordination chemistry.Oxypyriporphyrin and the related semiquinone system oxybenziporphyrin represent the first two members of a new class of aromatic porphyrinoids. - Keywords: aromaticity; porphyrins; pyridones; MacDonald condensation; tautomerizations
- Lash, Timothy D.,Chaney, Sun T.
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p. 944 - 948
(2007/10/03)
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- Macrocyclic complexes of yttrium, the lanthanides and the actinides having peripheral coupling functionalities
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Functionalized water soluble macrocyclic complexes of lanthanide, actinide and yttrium ions were obtained by metal templated, Schiff-base, cyclic condensation of: (1) a functionalized 1,2-diaminoethane and a dicarbonyl compound selected from the group consisting of 2,6-dicarbonylpyridine, 2,6-diformylpyridine, 2,5-dicarbonylfuran, 2,5-diformylfuran, 2,5-dicarbonylthiophene and 2,5-diformylthiophene; or (2) 1,2-diaminoethane and a ring-substituted heterocyclic dicarbonyl compound selected from a group consisting of substituted 2,6-dicarbonylpyridine, substituted 2,6-diformylpyridine, substituted 2,5-dicarbonylfuran, substituted 2,5-diformylfuran; substituted 2,5-dicarbonyl thiophene, and substituted 2,5-diformylthiophene. Coordination complexes thus formed are kinetically stable in dilute aqueous solution. They are further reacted, or coupled, through a substituent on the 1,2-diaminoethane or on the pyridine, furan, or thiophene moieties, to one of the following: proteinaceous materials, polysaccharides, other biologically compatible macromolecules or bridging molecules which, can be further reacted or coupled to the above mentioned substrates. These macrocyclic complexes are suitable in the preparation of reporter molecules and for magnetic resonance, radiation imaging and radiation therapy.
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