1891-19-6Relevant articles and documents
A Fluorine-18 Radiolabeling Method Enabled by Rhenium(I) Complexation Circumvents the Requirement of Anhydrous Conditions
Klenner, Mitchell A.,Pascali, Giancarlo,Zhang, Bo,Sia, Tiffany R.,Spare, Lawson K.,Krause-Heuer, Anwen M.,Aldrich-Wright, Janice R.,Greguric, Ivan,Guastella, Adam J.,Massi, Massimiliano,Fraser, Benjamin H.
, p. 6499 - 6503 (2017)
Azeotropic distillation is typically required to achieve fluorine-18 radiolabeling during the production of positron emission tomography (PET) imaging agents. However, this time-consuming process also limits fluorine-18 incorporation, due to radioactive decay of the isotope and its adsorption to the drying vessel. In addressing these limitations, the fluorine-18 radiolabeling of one model rhenium(I) complex is reported here, which is significantly improved under conditions that do not require azeotropic drying. This work could open a route towards the investigation of a simplified metal-mediated late-stage radiofluorination method, which would expand upon the accessibility of new PET and PET-optical probes.
Formation of 1,10-phenanthroline-N,N′-dioxide under mild conditions: The kinetics and mechanism of the oxidation of 1,10-phenanthroline by peroxomonosulfate ion (Oxone)
Bellér, Gábor,Szabó, Mária,Lente, Gábor,Fábián, István
, p. 5345 - 5353 (2016)
This paper confirms the unexpected formation of 1,10-phenanthroline-N,N′-dioxide (phenO2) when 1,10-phenanthroline (phen) is oxidized by peroxomonosulfate ion (PMS) in a neutral aqueous solution. The kinetics of oxidation of phen by PMS feature
1-Methyl-1,10-phenanthrolin-2(1H)-one (L) as a ligand to Eu(III): Crystal structure and luminescent properties of [Eu(L)3(NO3) 3] Dedicated to Professor George Christou on the occasion of his 60th birthday.
Akerboom, Sebastiaan,Van Den Elshout, Jos J.M.H.,Mutikainen, Ilpo,Fu, Wen Tian,Bouwman, Elisabeth
, p. 106 - 109 (2013)
A new coordination compound of Eu(III) with 1-methyl-1,10-phenanthroline- 2(1H)-one (L) as a ligand has been synthesized and characterized using infrared spectroscopy, elemental analysis and single crystal X-ray diffraction. The structure contains isolated [Eu(L)3(NO3)3] molecules interacting through extensive π-stacking. Photoluminescence studies demonstrate that the complex shows line-like emission characteristic of Eu(III) when excited in the ligand-centered absorption bands, with a quantum yield of 22% and a lifetime of 0.74 ms.
Hybrid bis-histidine phenanthroline-based ligands to lessen aβ-bound cu ros production: An illustration of cu(i) significance
Drommi, Marielle,Esmieu, Charlène,Hureau, Christelle,Rulmont, Clément
supporting information, (2021/12/24)
We here report the synthesis of three new hybrid ligands built around the phenanthroline scaffold and encompassing two histidine-like moieties: phenHH, phenHGH and H’phenH’, where H correspond to histidine and H’ to histamine. These ligands were designed to capture Cu(I/II) from the amyloid-β peptide and to prevent the formation of reactive oxygen species produced by amyloid-β bound copper in presence of physiological reductant (e.g., ascorbate) and dioxygen. The amyloid-β peptide is a well-known key player in Alzheimer’s disease, a debilitating and devasting neurological disorder the mankind has to fight against. The Cu-Aβ complex does participate in the oxidative stress observed in the disease, due to the redox ability of the Cu(I/II) ions. The complete characterization of the copper complexes made with phenHH, phenHGH and H’phenH’ is reported, along with the ability of ligands to remove Cu from Aβ, and to prevent the formation of reactive oxygen species catalyzed by Cu and Cu-Aβ, including in presence of zinc, the second metal ions important in the etiology of Alzheimer’s disease. The importance of the reduced state of copper, Cu(I), in the prevention and arrest of ROS is mechanistically described with the help of cyclic voltammetry experiments.
From Pyridine- N-oxides to 2-Functionalized Pyridines through Pyridyl Phosphonium Salts: An Umpolung Strategy
Bugaenko, Dmitry I.,Yurovskaya, Marina A.,Karchava, Alexander V.
supporting information, p. 6099 - 6104 (2021/08/03)
The reactions of pyridine-N-oxides with Ph3P under the developed conditions provide an unprecedented route to (pyridine-2-yl)phosphonium salts. Upon activation with DABCO, these salts readily serve as functionalized 2-pyridyl nucleophile equivalents. This umpolung strategy allows for the selective C2 functionalization of the pyridine ring with electrophiles, avoiding the generation and use of unstable organometallic reagents. The protocol operates at ambient temperature and tolerates sensitive functional groups, enabling the synthesis of otherwise challenging compounds.
A single iron porphyrin shows ph dependent switch between "push" and "pull" effects in electrochemical oxygen reduction
Bhunia, Sarmistha,Dey, Abhishek,Dey, Somdatta Ghosh,Mukherjee, Sudipta,Nayek, Abhijit
, p. 14564 - 14576 (2020/11/02)
The "push-pull"effects associated with heme enzymes manifest themselves through highly evolved distal amino acid environments and axial ligands to the heme. These conserved residues enhance their reactivities by orders of magnitude relative to small molecules that mimic the primary coordination. An instance of a mononuclear iron porphyrin with covalently attached pendent phenanthroline groups is reported which exhibit reactivity indicating a pH dependent "push"to "pull"transition in the same molecule. The pendant phenanthroline residues provide proton transfer pathways into the iron site, ensuring selective 4e-/4H+ reduction of O2 to water. The protonation of these residues at lower pH mimics the pull effect of peroxidases, and a coordination of an axial hydroxide ligand at high pH emulates the push effect of P450 monooxygenases. Both effects enhance the rate of O2 reduction by orders of magnitude over its value at neutral pH while maintaining exclusive selectivity for 4e-/4H+ oxygen reduction reaction.
Reaction of Pyridine-N-Oxides with Tertiary sp2-N-Nucleophiles: An Efficient Synthesis of Precursors for N-(Pyrid-2-yl)-Substituted N-Heterocyclic Carbenes
Bugaenko, Dmitry I.,Karchava, Alexander V.,Yurovskaya, Marina A.
supporting information, p. 5777 - 5782 (2020/12/01)
N-(Pyrid-2-yl)-substituted azolium and pyridinium salts, precursors for hybrid NHC-containing ligands, were obtained with excellent regioselectivity, employing a deoxygenative CH-functionalization of pyridine-N-oxides with substituted imidazoles, thiazoles, and pyridine. Unlike the traditional SNAr-based methods, this approach provides high yields for substrates bearing substituents of different electronic nature. The utility of azolium and pyridinium salts thus prepared was also highlighted by the synthesis of pyridyl-substituted imidazolyl-2-thione, benzodiazepine as well as 2-aminopyridines.
Copper-Catalyzed Regioselective C-H Amination of Phenol Derivatives with Assistance of Phenanthroline-Based Bidentate Auxiliary
Takamatsu, Kazutaka,Hayashi, Yoshihiro,Kawauchi, Susumu,Hirano, Koji,Miura, Masahiro
, p. 5336 - 5344 (2019/06/13)
A copper-catalyzed regioselective direct amination of phenol derivatives with diarylamines via phenanthroline-based bidentate auxiliary-directed C-H cleavage has been developed. This reaction proceeds smoothly with only a copper salt and air as a terminal oxidant to produce the corresponding o-aminophenols in good yields. Moreover, the directing group can be easily attached, detached, and recycled. Additionally, preliminary computational studies of the reaction with DFT have also been performed.
NNB-type tridentate boryl ligands enabling a highly active iridium catalyst for C–H borylation
Ding, Siyi,Wang, Linghua,Miao, Zongcheng,Li, Pengfei
, (2019/04/30)
Boryl ligands play a very important role in catalysis because of their very high electron-donating property. In this paper, NNB-type boryl anions were designed as tridentate ligands to promote aryl C–H borylation. In combination with [IrCl(COD)]2/su
With the antibacterial activity of the substituted 2 - amido - 1, 10 - eurepium (by machine translation)
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Paragraph 0018; 0019, (2019/06/07)
The invention relates to a compound of formula I is shown of a substituted 2 - amido - 1, 10 - eurepium antibacterial compound or its physiologically acceptable salt and their method of preparation, also relates to a pharmaceutical composition comprising said compound. Wherein each substituent defined as stated in claims. (by machine translation)
