14903-78-7Relevant articles and documents
Selective G-quadruplex DNA stabilizing agents based on bisquinolinium and bispyridinium derivatives of 1,8-naphthyridine
Dhamodharan,Harikrishna,Jagadeeswaran,Halder,Pradeepkumar
, p. 229 - 242 (2012)
Various biologically relevant G-quadruplex DNA structures offer a platform for therapeutic intervention for altering the gene expression or by halting the function of proteins associated with telomeres. One of the prominent strategies to explore the therapeutic potential of quadruplex DNA structures is by stabilizing them with small molecule ligands. Here we report the synthesis of bisquinolinium and bispyridinium derivatives of 1,8-naphthyridine and their interaction with human telomeric DNA and promoter G-quadruplex forming DNAs. The interactions of ligands with quadruplex forming DNAs were studied by various biophysical, biochemical, and computational methods. Results indicated that bisquinolinium ligands bind tightly and selectively to quadruplex DNAs at low ligand concentration (～0.2-0.4 μM). Furthermore, thermal melting studies revealed that ligands imparted higher stabilization for quadruplex DNA (an increase in the Tm of up to 21 °C for human telomeric G-quadruplex DNA and >25 °C for promoter G-quadruplex DNAs) than duplex DNA (ΔTm ≥ 1.6 °C). Molecular dynamics simulations revealed that the end-stacking binding mode was favored for ligands with low binding free energy. Taken together, the results indicate that the naphthyridine-based ligands with quinolinium and pyridinium side chains form a promising class of quadruplex DNA stabilizing agents having high selectivity for quadruplex DNA structures over duplex DNA structures.
Iron-Catalyzed Water Oxidation: O–O Bond Formation via Intramolecular Oxo–Oxo Interaction
Liao, Rong-Zhen,Su, Xiao-Jun,Xie, Fei,Zhang, Hong-Tao,Zhang, Ming-Tian
, p. 12467 - 12474 (2021)
Herein, we report the importance of structure regulation on the O?O bond formation process in binuclear iron catalysts. Three complexes, [Fe2(μ-O)(OH2)2(TPA)2]4+ (1), [Fe2(μ-O)(OH2)2(6-HPA)]4+ (2) and [Fe2(μ-O)(OH2)2(BPMAN)]4+ (3), have been designed as electrocatalysts for water oxidation in 0.1 M NaHCO3 solution (pH 8.4). We found that 1 and 2 are molecular catalysts and that O?O bond formation proceeds via oxo–oxo coupling rather than by the water nucleophilic attack (WNA) pathway. In contrast, complex 3 displays negligible catalytic activity. DFT calculations suggested that the anti to syn isomerization of the two high-valent Fe=O moieties in these catalysts takes place via the axial rotation of one Fe=O unit around the Fe-O-Fe center. This is followed by the O?O bond formation via an oxo–oxo coupling pathway at the FeIVFeIV state or via oxo–oxyl coupling pathway at the FeIVFeV state. Importantly, the rigid BPMAN ligand in complex 3 limits the anti to syn isomerization and axial rotation of the Fe=O moiety, which accounts for the negligible catalytic activity.
Elaboration of 1,8-naphthyridine-2,7-dicarboxaldehyde into novel 2,7-dimethylimine derivatives
Vu, Choua,Walker, DeeDee,Wells, Jason,Fox, Stephen
, p. 829 - 832 (2002)
The known 1,8-naphthyridine-2,7-dicarboxaldehyde was prepared by SeO2 oxidation of 2,7-dimethyl-1,8-naphthyridine. The dimethylated naphthyridine molecule was assembled from an adaptation of the Skraup synthesis using 2-amino-6-methylpyridine and crotonaldehyde to afford a reproducible 37% yield, and constitute a significant advance over the literature of this reaction. The condensation of 1,8-naphthyridine-2,7-dicarboxaldehyde with various primary amines (R = -C6H11, -CH2C6H5, -C(CH3)3, -C10H15, and CH2CH2SCH2CH3) in alcohol affords diimines l(a-e). The inherent crystallinity of 1(a-e) affords pure compounds in reasonable to excellent yields (ca. 70%) after evaporation of solvent and recrystallization. The anticipated spectroscopic features of (N=C-H) 1H nmr shift and v(C=N) in the ir spectrum appear around 8.50 δ and 1640 cm-1, respectively, for the series 1(a-e). These novel naphthyridines typically display the signature 1H nmr doublets at ca. 8.15-8.30 δ ascribed to the 3 and 4 naphthyridine protons, consistent with a mirror plane (through the quaternary carbons) perpendicular to the naphthyridine plane, and syn, syn relationships of the naphthyridine moiety with each imine nitrogen lone pair. Complexation studies of 1(a-e) with transition metals of biological relevance such as copper(I) and copper(II) will be reported elsewhere.
Photoinduced Trifluoromethylation of Arenes and Heteroarenes Catalyzed by High-Valent Nickel Complexes
Deolka, Shubham,Govindarajan, Ramadoss,Khaskin, Eugene,Fayzullin, Robert R.,Roy, Michael C.,Khusnutdinova, Julia R.
, p. 24620 - 24629 (2021/10/08)
We describe a series of air-stable NiIII complexes supported by a simple, robust naphthyridine-based ligand. Access to the high-valent oxidation state is enabled by the CF3 ligands on the nickel, while the naphthyridine exhibits either a monodentate or bidentate coordination mode that depends on the oxidation state and sterics, and enables facile aerobic oxidation of NiII to NiIII. These NiIII complexes act as efficient catalysts for photoinduced C(sp2)?H bond trifluoromethylation reactions of (hetero)arenes using versatile synthetic protocols. This blue LED light-mediated catalytic protocol proceeds via a radical pathway and demonstrates potential in the late-stage functionalization of drug analogs.
