112776-83-7Relevant academic research and scientific papers
Unprecedented strong lewis bases - Synthesis and methyl cation affinities of dimethylamino-substituted terpyridines
Hommes, Paul,Fischer, Christina,Lindner, Christoph,Zipse, Hendrik,Reissig, Hans-Ulrich
, p. 7647 - 7651 (2014)
A versatile method for the synthesis of functionalized 2,2′:6′, 2″-terpyridines by assembly of the terminal pyridine rings is presented. The cyclization precursors - bis-β-ketoenamides - are prepared from 4-substituted 2,6-pyridinedicarboxylic acids and a
Linear and Branched Pyridyl-Oxazole Oligomers: Synthesis and Circular Dichroism Detectable Effect on c-Myc G-Quadruplex Helicity
Rizeq, Natalia,Georgiades, Savvas N.
, p. 122 - 131 (2016)
Five unprecedented pyridyl-oxazole oligomers exhibiting either linear or branched connectivity of their subunits were developed as a family of potential G-quadruplex-interacting ligands. Our synthesis employed variations of a key Pd/Cu-mediated C-C cross-coupling/C-H activation reaction to gain access to the oligomer products from a small set of substituted pyridine building blocks. The effect of the compounds on the conformation of a c-myc oncogene promoter G-quadruplex was investigated by circular dichroism under various conditions. Some or all of the compounds induced detectable helicity enhancement in low-cation and Na+-rich Tris-HCl (pH 7.4) buffers, respectively, in which the helix was only partially prefolded.
Design and synthesis of polyoxazole-based macrocycles tethered with a phosphonate group
Qi, Fuling,Gao, Lianxun,Han, Fushe
, p. 585 - 591 (2014)
We present the design and synthesis of polyoxazole-based macrocycles containing a phosphonate group. A reliable route was established that allows for convenient and versatile incorporation of various phosphonate functionalities such as phosphonate ester, acid, and salt at the macrocyclic ring periphery. Such unprecedented macrocyclic compounds are anticipated to be appealing candidates as telomerase inhibitors. Copyright
Photocytotoxicity of Thiophene- And Bithiophene-Dipicolinato Luminescent Lanthanide Complexes
Rodrigues, Carime V.,Johnson, Katherine R.,Lombardi, Vincent C.,Rodrigues, Marcelo O.,Sobrinho, Josiane A.,De Bettencourt-Dias, Ana
, p. 7724 - 7734 (2021)
New thiophene-dipicolinato-based compounds, K2nTdpa (n = 1, 2), were isolated. Their anions are sensitizers of lanthanide ion (LnIII) luminescence and singlet oxygen generation (1O2). Emission in the visible and near-infrared regions was observed for the LnIII complexes with efficiencies (φLn) φEu = 33% and φYb = 0.31% for 1Tdpa2- and φYb = 0.07% for 2Tdpa2-. The latter does not sensitize EuIII emission. Fluorescence imaging of HeLa live cells incubated with K3[Eu(1Tdpa)3] indicates that the complex permeates the cell membrane and localizes in the mitochondria. All complexes generate 1O2 in solution with efficiencies (φO12) as high as 13 and 23% for the GdIII complexes of 1Tdpa2- and 2Tdpa2-, respectively. [Ln(nTdpa)3]3- (n = 1, 2) are phototoxic to HeLa cells when irradiated with UV light with IC50 values as low as 4.2 μM for [Gd(2Tdpa)3]3- and 91.8 μM for [Eu(1Tdpa)3]3-. Flow cytometric analyses indicate both apoptotic and necrotic cell death pathways.
Photo-responsive cyclodextrin/anthracene/Eu3+ supramolecular assembly for a tunable photochromic multicolor cell label and fluorescent ink
Zhou, Weilei,Chen, Yong,Yu, Qilin,Li, Peiyu,Chen, Xuman,Liu, Yu
, p. 3346 - 3352 (2019)
A photo-responsive supramolecular assembly was successfully constructed through the stoichiometric 2?:?1 non-covalent association of two 4-(anthracen-2-yl)pyridine-2,6-dicarboxylic acid (1) units in one γ-cyclodextrin (γ-CD) cavity, followed by the subsequent coordination polymerization of the γ-CD·12 (12 = two 1) inclusion complex with Eu(iii). Interestingly, owing to the photodimerization behavior of anthracene units and the excellent luminescence properties of Eu(iii), the Eu3+?γ-CD·12 system showed multicolor fluorescence emission from cyan to red by irradiation for 0-16 minutes. Moreover, white light emission with CIE coordinates (0.32 and 0.36) was achieved at 4 min. Importantly, white light-containing multicolor emission could be obtained in water, solid films and living cells. Especially, the Eu3+?γ-CD·12 system could tag living cells with marvelous white fluorescence and display no obvious cytotoxicity. Thus, this supramolecular assembly offers a new pathway in the fields of tunable photochromic fluorescent ink and cell labelling.
Hirshfeld surface investigation of structure-directing interactions within dipicolinic acid derivatives
Martin, Adam D.,Britton, Joshua,Easun, Timothy L.,Blake, Alexander J.,Lewis, William,Schr?der, Martin
, p. 1697 - 1706 (2015)
Six compounds based on dipicolinic acid esters have been synthesized and Hirshfeld surfaces used to investigate the structure-directing effects of functional groups in controlling their solid-state behavior. Compounds 1-4 are 4-bromo dipicolinic acid esters substituted with methyl, ethyl, propyl, and benzyl groups, respectively. The main structure-directing motif within 1-3 is a pairwise O···H interaction involving two carbonyl oxygen atoms and two aromatic H atoms. The introduction of bulky benzyl groups in 4 forces a significant change in the position of this interaction. Compounds 2 and 4 were used in Suzuki coupling reactions to prepare extended analogues 5 and 6, respectively, and their solid-state behavior was also studied using Hirshfeld surfaces. Extension of these dipicolinic acid esters results in the complete loss of the pairwise O···H interaction in 5, where the dominant structure-directing motifs are π-based interactions. However, the pairwise O···H interaction reappears for the more flexible 6, demonstrating control of the solid-state structure of these dipicolinic acid derivatives through the choice of functional groups.
Synthesis of a 'propeller-like' oligoheteroaryl with alternating pyridine and oxazole motifs
Georgiades, Savvas N.,Rizeq, Natalia
, p. 489 - 493 (2015)
The molecular architecture of oligomeric pyridyl-oxazole compounds is key to determining their mode of interaction with G-quadruplex DNA structures, which is a family of prominent anticancer biomolecular targets. We report herein an efficient synthetic route that begins with chelidamic acid and affords, in just seven steps, an unusual 'propeller-like' pyridyl-oxazole architecture with alternating pyridine and oxazole rings, that has not been yet validated as a G-quadruplex binder. The synthesis employs Van Leusen chemistry for the construction of oxazole rings from aldehydes, and two Pd(II)/Cu(I)-mediated cross-coupling reactions involving C-H activation of oxazoles for the formation of C-C bonds between bromopyridine intermediates and oxazole fragments. This modular synthesis was designed to be amenable to the construction of analogues.
The development of a practical and reliable large-scale synthesis of 2,6-diamino-4-bromopyridine
Nettekoven, Matthias,Jenny, Christian
, p. 38 - 43 (2003)
A novel, safer, and efficient synthetic route to 2,6-diamino-4-bromopyridine has been developed. In discovery research a five-step synthesis afforded 2,6-diamino-4-bromopyridine in 56% yield with a double Curtius rearrangement as a key transformation. Due to potential safety concerns on larger scale an alternative synthetic strategy was necessary. Starting from 2,4-dibromopyridine-N-oxide two complementary procedures have been developed to access 2,6-diamino-4-bromopyridine. The four-step procedure yielded in 28% overall, and the five-step procedure, in 33% overall 2,6-diamino-4-bromopyridine in a safe and straightforward manner using a regioselective 2,6-diamination reaction as key step. Additionally, a general route to unsymmetrical substituted pyridine N-oxide derivatives is disclosed.
Efficient Syntheses of New Super Lewis Basic Tris(dialkylamino)-Substituted Terpyridines and Comparison of Their Methyl Cation Affinities
Kleoff, Merlin,Suhr, Simon,Sarkar, Biprajit,Zimmer, Reinhold,Reissig, Hans-Ulrich,Marin-Luna, Marta,Zipse, Hendrik
, p. 7526 - 7533 (2019)
Syntheses of very electron-rich dialkylamino-substituted 2,2':6',2''-terpyridines (TPYs) were adapted to moderate scale preparation without tedious purification of intermediates. The key 4'-bromo-6,6''-dimethyl-2,2':6',2''-terpyridine-4,4''-diyl bisnonaflate is now available in gram quantities. Its nucleophilic aromatic substitution with dimethylamine provided mixtures of 4'-bromo-substituted 4,4''-bis(dimethylamino)-TPY and the tris(dimethylamino)-TPY. The bromo compound was used in a Buchwald–Hartwig amination to provide the tris(dimethylamino)-TPY in excellent yield. The 4'-bromo substituent was reductively removed to furnish the bis(dimethylamino)-TPY. The same sequence of reactions with pyrrolidine as nucleophile leads to the hitherto unknown pyrrolidino-TPYs. Calculations at the MP2(FC)/6–31+G(2d,p)//B98/6-31G(d) level predict very high methyl cation affinities for compounds of this type, with the 4,4',4''-tri(pyrrolidin-1-yl)-TPY being the most Lewis basic TPY synthesized to date. The efficiently prepared electron-rich TPYs should be excellent ligands for many applications.
Reaction of 1,2-bis(2,6-dicarboxypyridin-4-yl)ethyne with Co(II) generates coordination monomers not polymers: Crystal structure of 4-(2,6- dicarboxypyridin-4-yl)ethynylpyridine-2,6-dicarboxylatotriaqua cobalt(II) monohydrate
Yigit, Mehmet V.,Cooper, Christopher G. F.,Wang, Yu,Moulton, Brian,MacDonald, John C.
, p. 371 - 379 (2006)
Reaction and crystallization of 1,2-bis(2,6-dicarboxypyridin-4-yl)ethyne with Co(II) produces crystals containing monomers of 4-(2,6-dicarboxypyridin-4- yl)ethynylpyridine-2,6-dicarboxylatotriaqua cobalt(II) monohydrate complex (1), [Co(C16H6N2O8)(H2O) 3]·H2O, instead of a rigid 1-D metal-organic framework consisting of a linear coordination polymer. This complex crystallizes in the monoclinic space group C2/c with a=6.8028(9) A, b=36.781(5) A, c=7.5135(9) 2.474(2)° and Z=4. The complex sits on a symmetry axis such that the two halves of the molecule are related by two-fold rotation symmetry. The molecules form layers in which the molecules are joined by intermolecular O-H...O interactions involving hydrogen bonds between CO2H...CO2-, H2O...CO 2-, H2O...CO2H and H 2O...H2O groups.
