39621-11-9Relevant articles and documents
A Design Strategy for Single-Stranded Helicates using Pyridine-Hydrazone Ligands and PbII
Lobo, Maureen J.,Moratti, Stephen C.,Hanton, Lyall R.
, p. 1184 - 1193 (2019)
The reactions of py-hz ligands (L1–L5) with Pb(CF3SO3)2?H2O resulted in some rare examples of discrete single-stranded helical PbII complexes. L1 and L2 formed non-helical mononuclear complexes [PbL1(CF3SO3)2]?CHCl3 and PbL2(CF3SO3)2][PbL2CF3SO3]CF3SO3?CH3CN, which reflected the high coordination number and effective saturation of PbII by the ligands. The reaction of L3 with PbII resulted in a dinuclear meso-helicate [Pb2L3(CF3SO3)2Br]CF3SO3?CH3CN with a stereochemically-active lone pair on PbII. L4 directed single-stranded helicates with PbII, including [Pb2L4(CF3SO3)3]CF3SO3?CH3CN and [Pb2L4CF3SO3(CH3OH)2](CF3SO3)3?2 CH3OH?2 H2O. The acryloyl-modified py-hz ligand L5 formed helical and non-helical complexes with PbII, including a trinuclear PbII complex [Pb3L5(CF3SO3)5]CF3SO3?3CH3CN?Et2O. The high denticity of the long-stranded py-hz ligands L4 and L5 was essential to the formation of single-stranded helicates with PbII.
New chiral ligands, pyridinooxathianes, for palladium-catalyzed asymmetric allylic alkylation
Okuyama, Yuko,Nakano, Hiroto,Kabuto, Chizuko,Nozawa, Erica,Takahashi, Kouichi,Hongo, Hiroshi
, p. 457 - 469 (2002)
New types of pyridinooxathiane ligands have been synthesized and their abilities as chiral catalysts examined in the palladium-catalyzed allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate.
New pyrazolino and pyrrolidino[60]fullerenes: the introduction of the hydrazone moiety for the formation of metal complexes
Romero, Elkin L.,Cabrera-Espinoza, Andrea,Ortiz-Pe?a, Nathaly,Soto-Monsalve, Mónica,Zuluaga, Fabio,D'Vries, Richard F.,Chaur, Manuel N.
, (2017)
The [3 + 2] cycloaddition reaction of C60 with pyridine-derived hydrazones (acting as dipolar reagents) was successfully conducted resulting in fullerene derivatives 5a, 5b. The compounds were characterized by means of NMR, UV–Vis spectroscopy, and X-ray crystallography. The electrochemical behavior was also investigated. The fulleropyrazoline 5a exhibits anodically shifted reduction potentials of about 100 mV when compared with those for C60, whereas 5b exhibits cathodic shifts relative to pristine C60. The complexation reaction of 5b with metallic ions (Zn2+, Cd2+, and Fe2+) was achieved. Job and Benesi–Hildebrand analysis confirmed the formation of complexes with a molar ratio of 1:1 and binding constants between 2.26 × 105 and 1.59 × 105 M?1. Electrochemistry of these complexes showed a marked influence of the metal ion on the reduction potentials. Copyright
Selective oxidation of a single primary alcohol function in oligopyridine frameworks
Ziessel, Raymond,Nguyen, Patrick,Douce, Laurent,Cesario, Michele,Estournes, Claude
, p. 2865 - 2868 (2004)
(Equation Presented) A variety of mono-oxidized pyridine, bipyridine, terpyridine, and pyridine/pyridazine are readily prepared under mild conditions using Pyrolusite MnO2. This phase has been characterized by means of X-ray powder diffraction
Control of self-assembly through the influence of terminal hydroxymethyl groups on the metal coordination of pyrimidine?hydrazone CU(ii) complexes
Hutchinson, Daniel J.,Hanton, Lyall R.,Moratti, Stephen C.
, p. 5923 - 5934 (2010)
The synthesis and characterization of 6-hydroxymethylpyridine-2- carboxaldehyde (2-methyl-pyrimidine-4,6-diyl)bis(1-methylhydrazone) (1) is reported. Ligand 1 was designed as a ditopic pyrimidine?hydrazone molecular strand with hydroxymethyl groups attached to the terminal pyridine rings. Coordination of 1 with Cu(ClO4)2·6H2O or Cu(SO3CF3)2·4H2O in a 1:2 molar ratio resulted in the dinuclear Cu(II) complexes [Cu21(CH 3CN)4](ClO4)4·CH 3CN (4) and [Cu21(SO3CF3) 2(CH3CN)2](SO3CF3) 2·CH3CN (5) · X-ray crystallography and 1H NMR NOESY experiments showed that 1 adopted a horseshoe shape with both pyrimidine?hydrazone (pym?hyz) bonds in a transoid conformation, while 4 and 5 were linear in shape, with both pym?hyz bonds in a cisoid conformation. Coordination of 1 with Cu(ClO4)2·6H2O or Cu(SO3CF3)2·4H2O in a 1:1 molar ratio resulted in three different bent complexes, [Cu(1H)(ClO 4)2](ClO4) (6), [Cu(1H)(CH3CN)] (ClO4)3·0.5H2O (7), and [Cu1(SO 3CF3)]2(SO3CF3) 2·CH3CN (8), where the pym?hyz bond of the occupied coordination site adopted a cisoid conformation, while the pym?hyz bond of the unoccupied site retained a transoid conformation. Both 6 and 7 showed protonation of the pyridine nitrogen donor in the empty coordination site; complex 8, however, was not protonated. A variety of Cu(II) coordination geometries were seen in structures 4 to 8, including distorted octahedral, trigonal bipyramidal, and square pyramidal geometries. Coordination of the hydroxymethyl arm in the mononuclear Cu(II) complexes 6, 7, and 8 appeared to inhibit the formation of a [2 × 2] grid by blocking further access to the Cu(II) coordination sphere. In addition, the terminal hydroxymethyl groups contributed to the supramolecular structures of the complexes through coordination to the Cu(II) ions and hydrogen bonding.
A new catalytic approach for aerobic oxidation of primary alcohols based on a Copper(I)-thiophene carbaldimines
Lagerspets, Emi,Valbonetti, Evelyn,Eronen, Aleksi,Repo, Timo
, (2021/06/03)
We report here novel Cu(I) thiophene carbaldimine catalysts for the selective aerobic oxidation of primary alcohols to their corresponding aldehydes and various diols to lactones or lactols. In the presence of the in situ generated Cu(I) species, a persistent radical (2,2,6,6-tetramethylpiperdine-N-oxyl (TEMPO)) and N-methylimidazole (NMI) as an auxiliary ligand, the reaction proceeds under aerobic conditions and at ambient temperature. Especially the catalytic system of 1-(thiophen-2-yl)-N-(4-(trifluoromethoxy)phenyl)methanimine (ligand L2) with copper(I)-iodide showed high reactivity for all kind of alcohols (benzylic, allylic and aliphatic). In the case of benzyl alcohol even 2.5 mol% of copper loading gave quantitative yield. Beside high activity under aerobic conditions, the catalysts ability to oxidize 1,5-pentadiol to the corresponding lactol (86% in 4 h) and N-phenyldiethanolamine to the corresponding morpholine derivate lactol (86% in 24 h) is particularly noteworthy.
Bioinspired Nitroalkylation for Selective Protein Modification and Peptide Stapling
Adebomi, Victor,Mahesh, Sriram,Muneeswaran, Zilma P.,Raj, Monika
supporting information, p. 2793 - 2801 (2020/01/25)
Nitroalkanes react specifically with aldehydes, providing rapid, stable, and chemoselective protein bioconjugation. These nitroalkylated proteins mimic key post-translational modifications (PTMs) of proteins and can be used to understand the role of these
