30413-54-8Relevant academic research and scientific papers
Halogen Bond Asymmetry in Solution
Lindblad, Sofia,Mehmeti, Krenare,Veiga, Alberte X.,Nekoueishahraki, Bijan,Gr?fenstein, Jürgen,Erdélyi, Máté
, p. 13503 - 13513 (2018)
Halogen bonding is the noncovalent interaction of halogen atoms in which they act as electron acceptors. Whereas three-center hydrogen bond complexes, [D···H···D]+ where D is an electron donor, exist in solution as rapidly equilibrating asymmetric species, the analogous halogen bonds, [D···X···D]+, have been observed so far only to adopt static and symmetric geometries. Herein, we investigate whether halogen bond asymmetry, i.e., a [D-X···D]+ bond geometry, in which one of the D-X bonds is shorter and stronger, could be induced by modulation of electronic or steric factors. We have also attempted to convert a static three-center halogen bond complex into a mixture of rapidly exchanging asymmetric isomers, [D···X-D]+ ? [D-X···D]+, corresponding to the preferred form of the analogous hydrogen bonded complexes. Using 15N NMR, IPE NMR, and DFT, we prove that a static, asymmetric geometry, [D-X···D]+, is obtained upon desymmetrization of the electron density of a complex. We demonstrate computationally that conversion into a dynamic mixture of asymmetric geometries, [D···X-D]+ r← [D-X···D]+, is achievable upon increasing the donor-donor distance. However, due to the high energetic gain upon formation of the three-center-four-electron halogen bond, the assessed complex strongly prefers to form a dimer with two static and symmetric three-center halogen bonds over a dynamic and asymmetric halogen bonded form. Our observations indicate a vastly different preference in the secondary bonding of H+ and X+. Understanding the consequences of electronic and steric influences on the strength and geometry of the three-center halogen bond provides useful knowledge on chemical bonding and for the development of improved halonium transfer agents.
Design, synthesis, and biological evaluation of novel 2′-methyl-2′-fluoro-6-methyl-7-alkynyl-7-deazapurine nucleoside analogs as anti-Zika virus agents
Yao, Guoqiang,Yu, Jianchen,Lin, Cai,Zhu, Yujia,Duan, Anna,Li, Mengfeng,Yuan, Jie,Zhang, Jiancun
, (2022/03/23)
Zika virus (ZIKV) is a mosquito-borne flavivirus and outbreaks of ZIKV have been reported in Africa, Americas and other parts of the world lately. The ZIKV epidemic has received extensive attention due to its ability to cause serious medical consequences and complications such as microcephaly and Guillain-Barre syndrome in recent years. Up to now, there are no specific treatments or vaccines available for ZIKV infection, which highlights the urgent need for developing new therapies. In this work, we designed and synthesized a series of novel 6-methyl-7-acetylenenyl-7-deazapurine nucleoside analogs as potential inhibitors of ZIKV replication. The biological activities against ZIKV replication were evaluated and the structure-activity relationship (SAR) was also studied. Among the compounds evaluated, nucleoside analog 38 (EC50 = 2.8 ± 0.8 μM, EC90 = 6.8 ± 2.3 μM) showed the most potent anti-ZIKV activity with low cytotoxicity (CC50 = 54.1 ± 6.9 μM) in an A549 based cellular model. The inhibitory activity of 38 was about 5 times more potent than the positive control NITD008. Notably, 38 showed similar inhibition potency against different ZIKV strains (ZG-01 and MR766) in a variety of host cell types including SNB19, A549, Huh7, Vero. In addition, 38 (Kd = 1.87 μM) has a stronger affinity to ZIKV RNA-dependent RNA polymerase (RdRp) protein than NITD008 (Kd = 3.43 μM) in the non-phosphorylation assay. These results indicated that compound 38 may serve as a promising candidate in future anti-ZIKV drug discovery.
Substituent Effects on the [N-I-N]+ Halogen Bond
Carlsson, Anna-Carin C.,Mehmeti, Krenare,Uhrbom, Martin,Karim, Alavi,Bedin, Michele,Puttreddy, Rakesh,Kleinmaier, Roland,Neverov, Alexei A.,Nekoueishahraki, Bijan,Gr?fenstein, Jürgen,Rissanen, Kari,Erdélyi, Máté
, p. 9853 - 9863 (2016/08/19)
We have investigated the influence of electron density on the three-center [N-I-N]+ halogen bond. A series of [bis(pyridine)iodine]+ and [1,2-bis((pyridine-2-ylethynyl)benzene)iodine]+ BF4- complexes substituted with electron withdrawing and donating functionalities in the para-position of their pyridine nitrogen were synthesized and studied by spectroscopic and computational methods. The systematic change of electron density of the pyridine nitrogens upon alteration of the para-substituent (NO2, CF3, H, F, Me, OMe, NMe2) was confirmed by 15N NMR and by computation of the natural atomic population and the π electron population of the nitrogen atoms. Formation of the [N-I-N]+ halogen bond resulted in >100 ppm 15N NMR coordination shifts. Substituent effects on the 15N NMR chemical shift are governed by the π population rather than the total electron population at the nitrogens. Isotopic perturbation of equilibrium NMR studies along with computation on the DFT level indicate that all studied systems possess static, symmetric [N-I-N]+ halogen bonds, independent of their electron density. This was further confirmed by single crystal X-ray diffraction data of 4-substituted [bis(pyridine)iodine]+ complexes. An increased electron density of the halogen bond acceptor stabilizes the [N···I···N]+ bond, whereas electron deficiency reduces the stability of the complexes, as demonstrated by UV-kinetics and computation. In contrast, the N-I bond length is virtually unaffected by changes of the electron density. The understanding of electronic effects on the [N-X-N]+ halogen bond is expected to provide a useful handle for the modulation of the reactivity of [bis(pyridine)halogen]+-type synthetic reagents.
MGLUR REGULATORS
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Page/Page column 28, (2014/09/03)
Provided herein are compounds of the formula I: (I), as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment or prevention of mGluR5 mediated disorders, such as acute and/or chronic neurological disorders, cognitive disorders and memory deficits, as well as acute and chronic pain.
METABOTROPIC GLUTAMATE RECEPTOR MODULATORS
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Page/Page column 111-112, (2012/05/05)
The invention relates to heterocyclic derivatives of formula (I) as well as their pharmaceutically acceptable salts. The invention further relates to a process for the preparation of such compounds. The compounds of the invention are mGluR5 modulators and are therefore useful for the control and prevention of acute and/or chronic neurological disorders wherein Y, W, R1, R2 and R3 are as defined in claim 1.
SYNTHESIS OF CERTAIN DIPYRIDYLACETYLENES USING PALLADIUM-CATALYZED CROSS-COUPLING OF ETHYNYL- AND HALOPYRIDINES
Karchava, A. V.,Maksimova, F. V.,Yurovskaya, M. A.
, p. 1195 - 1199 (2007/10/03)
A series of dipyridylacetylenes were obtained by reacting ethynylpyridines with chloro- and bromopyridines during catalysis with phosphino complexes of palladium in the presence of copper iodide and a base.
Reductive Amination of Ethynylpyridines with Sodium Cyanoborohydride
Sakamoto, Takao,Nagata, Hideo,Kondo, Yoshinori,Sato, Kaori,Yamanaka, Hiroshi
, p. 4866 - 4872 (2007/10/02)
In order to investigate the structure-activity relationship of betahistine derivatives, a general synthesis of methylated 2-(2-methylaminoethyl)pyridines was developed based on the addition of methylamine hydrochloride to methylated 2-ethynylpyridines under reductive conditions.In addition, the scope and limitations of the reductive addition were briefly examined.For example, the reaction proceeded smoothly with p-nitrophenylacetylene, whereas phenylacetylene itself did not react with methylamine.Keywords - ethynylpyridine; sodium cyanoborohydride; reductive amination; betahistine; palladium-catalyzed reaction; ethyl pyridineacetate; 2-(2-pyridyl)ethylamine
