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1.
Native reactive electrophilic species (RES) are long-recognized regulators of pathophysiology; yet, knowledge surrounding how RES regulate context-specific biology remains limited. The latest technological advances in profiling and precision decoding of RES sensing and signaling have begun to bring about improved understanding of localized RES regulatory paradigms. However, studies in purified systems — prerequisites for gaining structure/function insights — prove challenging. We here introduce emerging chemical biology tools available to probe RES signaling, and the new knowledge that these tools have brought to the field. We next discuss existing structural data of RES-sensor proteins complexed with electrophilic metabolites or small molecule drugs (limited to <300 Da), including challenges faced in acquiring homogenous RES-bound proteins. We further offer considerations that could promote enhanced understanding of RES regulation derived from three-dimensional structures of RES-modified proteins. 相似文献
2.
Prof. Dr. Mieczysław Mąkosza 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(19):5536-5545
In this overview, it is shown that there are many initial reactions between nitroarenes and nucleophiles: addition to the electron‐deficient ring at positions occupied by halogen and hydrogen atoms, addition to the nitro group, single‐electron transfer (SET), and other types of initial reactions. The resulting intermediates react further in a variety of ways to form products of nucleophilic substitution of a halogen atom (SNAr), a hydrogen atom (SNArH), and others. Many variants of these processes are briefly discussed, particularly in relation of rates of the initial reactions and further transformations. 相似文献
3.
有机反应按成键方式可以分为自由基反应、离子型反应和协同反应,基础有机化学中涉及的大部分反应属于离子型反应。掌握反应物的电性结构,清楚反应物中的亲核部位和亲电部位,不仅有助于学生理解离子型反应历程,轻松记忆反应,而且有助于学生举一反三,触类旁通,推导出课本中未曾讲述的反应。 相似文献
4.
三环己基氢氧化锡分别与吡咯啶二硫代氨基甲酸钠和邻苯二甲酰亚胺反应,合成了三环己基锡吡咯啶二硫代氨基甲酸酯(1)和三环己基锡邻苯二甲酰亚胺配合物(2)。化合物经IR、1H NMR、元素分析表征,用X射线衍射法测定了晶体结构,化合物1属正交晶系,空间群P212121,晶体学参数:a=1.228 06(3)nm,b=1.238 20(2)nm,c=1.662 54(3)nm,Z=4,V=2.528 03(9)nm3,Dc=1.351 g.cm-3,μ(Mo Kα)=1.184 mm-1,F(000)=1 072,R1=0.048 7,wR2=0.121 0;化合物2属正交晶系,空间群P212121,晶体学参数:a=1.244 70(19)nm,b=1.269 45(19)nm,c=1.587 7(2)nm,Z=4,V=2.508 7(6)nm3,Dc=1.362 g.cm-3,μ(Mo Kα)=1.039 mm-1,F(000)=1 064,R1=0.049 9,wR2=0.128 4,中心锡原子均为畸变四面体构型。对化合物进行了量子化学从头计算,探讨了化合物的稳定性、分子轨道能量以及前沿分子轨道的组成特征。 相似文献
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Prof. Dr. Barry M. Trost Dr. Christopher A. Kalnmals 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(9):1906-1921
Metal-catalyzed allylic alkylation reactions between dual nucleophiles and dual electrophiles represent a powerful set of methods for the synthesis of small-, medium-, and even large-sized rings. Using this strategy, a handful of simple allylic diol derivatives can be transformed into a broad array of complex carbo- and heterocycles of varying ring sizes in just a single step. Because of their ability to rapidly generate complexity, annulative allylic alkylation reactions between dual nucleophiles and dual electrophiles have been extensively employed in the total synthesis of both natural products and pharmaceutical compounds. 相似文献
6.
《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):1213-1225
Abstract The synthesis of two new methacrylate esters containing morpholine and pyrrolidine group are described. The monomers produced from the reaction of corresponding morpholino chloroacetamide and pyrrolidino chloroacetamide with sodium methacrylate were polymerized in DMSO solution at 65°C using AIBN as an initiator. The monomers and their polymers were characterized by Fourier transform infrared (FTIR), 1H‐ and 13C‐NMR spectroscopy. The glass transition temperature of the polymers were investigated by DSC and thermal decomposition activation energies were calculated by the Ozawa method using the SETARAM Labsys thermogravimetric analysis (TGA) thermobalance, respectively. By using gel permeation chromatography, weight average (M¯w) and number average (M¯n) molecular weights and polidispersity indices of the polymers were determined. 相似文献
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Gisbert Tuchalski Franziska Emmerling Karsten Grger Andr Hnsicke Thomas Nagel Günter Reck 《Journal of Molecular Structure》2006,800(1-3):28-44
The molecular and crystal structures of the hydrochlorides of d-nebivolol, dl-nebivolol, and seven nebivolol isomers have been determined by X-ray structure analysis. The absolute configuration of all the compounds could be determined unambiguously using anomal dispersion effects. Two compounds, dl-nebivolol (NEB-1d,l) and the (S,R,S,R) nebivolol isomer (NEB-6), crystallize as racemic mixtures in the centrosymmetric space group P-1. d-Nebivolol and six nebivolol isomers crystallize in space group P212121. The d- and l-nebivolol molecules in NEB-1d and NEB-1d,l adopt a conformation which is significantly different compared with that of all nebivolol isomers. With the exception of dl-nebivolol (NEB-1d,l) numerous intermolecular hydrogen bonds connect the molecules forming molecular layers. 相似文献
9.
Crystals of Ba3ZnSb2O9 have been grown by a high-temperature solid-state reaction and characterized by single-crystal X-ray diffraction.Ba3ZnSb2O9 crystallizes in the hexagonal P63/mmc space group with a = 5.8663(4),c = 14.478(2) ,V = 431.49(8) 3,Z = 2 and R(all data) = 0.0167.The structure of Ba3ZnSb2O9 consists of pairs of face-sharing Sb2O9 bi-octahedra connected via corners with two single layers of mutually isolated ZnO6 octahedra.Each Ba2+ ion is bonded to 12 oxygen atoms.The UV-vis absorption spectrum of the compound has been investigated.Additionally,the calculations of band structure and density of states have also been performed with density functional theory method.The obtained results tend to support the experimental data of the absorption spectrum. 相似文献
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Hassan Keypour Musa AhmadiMajid Rezaeivala Abdolkarim ChehreganiReza Golbedaghi Allan G. Blackman 《Polyhedron》2011,30(11):1865-1870
Two new branched pentadentate amines (N5), 3,7-bis(2-pyridylmethyl)-5,5-dimethyl-3,7-diazaheptane-1-amine (1) and 4,8-bis(2-pyridylmethyl)-6,6-dimethyl-4,8-diaza octane-1-amine (2) have been prepared. These have been used to synthesis two new Schiff base complexes containing a pyridine and 2-pyridylmethyl pendant arm, by template [1+1] condensation of pyridine-2-carbaldehyde with the amines in the presence of Mn(II) in methanol. Elemental and spectral results are used to characterize the complexes and their structures are confirmed by single crystal X-ray diffraction studies. The structure of MnL1(ClO4)2 indicates that in the solid state the Mn(II) ion adopts a slightly distorted octahedral geometry. The crystal structure of [Ni(1)(MeCN)](ClO4)2 is also reported and exhibits a slightly distorted octahedral geometry. Also the synthesized complexes were screened for their antibacterial activity against Escherichia coli (Lio), Serratia marcescens (PTCC 1330), Staphylococcous aureus (ATCC 6633), and Proteus vulgaris (Lio) and results showed that the all complexes have antibacterial effects and [NiL1](ClO4)2, [MnL2](ClO4) and [MnL1](ClO4)2 have more effective ones against E. coli. 相似文献
12.
Eli Shalom Khuloud Takrouri Israel Goldberg Jehoshua Katzhendler Morris Srebnik 《应用有机金属化学》2005,19(3):391-392
The conformation around the boron atom is nearly tetrahedral, with Br? B? Br bond angles of 109.14(19)° and slightly wider N? B? C bond angles up to 113.6(3)°. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
13.
Fluorotitanates (LH)2[TiF6]·nH2O (1: R = pyridine, n = 1, 2: R = 2-picoline, n = 2, 3: R = 2,6-lutidine, n = 0, 4: R = 2,4,6-collidine, n = 0) and (LH)[TiF5(H2O)] (3a: L = 2,6-lutidine) have been synthesized by the reaction of pyridine or corresponding methyl substituted pyridines and titanium dioxide dissolved in hydrofluoric acid. The crystal structures of ionic compounds 1, 2, 3, 3a and 4 have been determined by single-crystal X-ray diffraction analysis. The hydrogen bonding led to the formation of discrete (LH)2[TiF6] units (4), chains (1-3), and layers (3a). The additional π-π interactions present in 1, 2, and 4 results in chain structures of 1 and 4 and in a layer structure of 2. The [TiF6]2− and [TiF5(H2O)]− anions were observed by 19F NMR spectroscopy in aqueous solutions of 1, 2, 3, 3a and 4. 相似文献
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N. Vedernikov R. Miftakhov S. V. Borisoglebski K. G. Caulton B. N. Solomonov 《Chemistry of Heterocyclic Compounds》2002,38(4):406-416
Condensation of 2-pyridylmethyllithium or (6-methyl-2-pyridyl)methyllithium nucleophiles and pyridine, 2-picoline, or 4-tert-butylpyridine as electrophiles leads to new polydentate N-donor ligands, methyl-, tert-butyl-substituted tripyridinedimethanes, or to tripyridinedimethane itself, in good or high yields. Depending on the reagent ratio, solvent used, and reaction conditions, the corresponding intermediate dipyridinemethanes can be minor by-product or major products of the condensation. In contrast to 2-pyridylmethyllithium, lithiated 2-isopropylpyridine does not react with pyridine electrophiles. Vice versa, nucleophilic substitution at the C(2)-pyridine carbon of 2,2-bis(2-pyridyl)propane with 2-pyridylmethyllithium takes place to produce products of condensation of 2-isopropylpyridine and dipyridylmethyllithium. DFT calculations of the Gibbs free energies of reactions combined with pK
a values of the CH-acids involved help to explain the reactivity observed. 相似文献
16.
K. V. P. Pa Van Kumar K. Praveen Kumar M. Vijjulatha K. C. Kumara Swamy 《Journal of Chemical Sciences》2004,116(6):311-317
The compounds S(6-t-Bu-4-Me-C6H2O)2P(O)Cl (1), CH2(6-t-Bu-4-Me-C6H2O)2P(O)Cl (2) and (2,2′-C20H12O2)P(O)Cl (3) react with diazabicycloundecene (DBU) to give rise to, predominantly, the phosphonate compounds [S(6-t-Bu-4-Me-C6H6O)2P(O)(DBU)]+[Cl]− (4), [CH2(6-t-Bu-4-Me-C6H2O)2P(O) (DBU)]+[Cl]− (5) and [(2,2′-C20Hi2O2)P(0)(DBU)]+[Cl]- (6). The first two compounds could be isolated in the pure state. In analogous reactions of 1 and 2 with diazabicyclononene
(DBN) or N-methyl imidazole, only the pyrophosphates [S(6-t-Bu-4-Me-C6H2O)2P(O)]2O (7) and [CH2(6-t-Bu-4-Me-C6H2O)2P(O)]2O (8) could be isolated, although the reaction mixture showed several other compounds in the phosphorus NMR. A possible pathway
for the formation of phosphonate salts is proposed. The X-ray crystal structures of4,7 and8 are also discussed. 相似文献
17.
Various substituted benzimidazoles and imidazolo[4,5-b] pyridines 5a-c have been prepared by condensation of appropriate diamines and aldehydes in nitrobenzene. This method has been utilized to synthesize compounds 5f-h, which are analogues of the DNA binding fluorochrome Hoechst 33258. 相似文献
18.
The anions binding properties of the pyrrole-based tripodal anion receptor 1 were studied by X-ray crystallography, 1H NMR, and ESI-MS. It revealed that this new tripodal receptor has a preference for binding H2PO4− and F− ions. 相似文献
19.
Ulrich Siemeling Sabine Tomm Clemens Bruhn 《Journal of organometallic chemistry》2006,691(23):5056-5059
The pyrazinium salt [FcCH2pyz][BF4] (1) and the quinoxalinium salt [FcCH2quin][BF4] (2) were prepared by the reaction of [FcCH2][BF4] with pyrazine and quinoxaline, respectively and characterised by spectroscopic methods, cyclic voltammetry and by single-crystal X-ray diffraction, which revealed the absence of any π-π-stacking motifs in the crystal structures. 相似文献
20.
The structure of (E)-N-[(E)-3-[(lR,2R)-2-(3,4-dibromo-phenyl)-l-fluro-cyclopropyl]- allylidene]-2-0-tolyl-acetamide (C21HIsONFBrz, Mr = 479.18) has been determined by X-ray single- crystal diffraction and theoretical calculations to establish the configuration, stereochemistry and a stable conformation of the molecule. The compound crystallizes in the monoclinic space group P21/c, a = 28.3452(10), b = 4.9311(10), c = 14.257(2) A, fl = 102.7654(10), V = 1943.5(5) A3 and Z = 4. The structure has been refined to the final R = 0.05 for the observed structure factors with 1 〉 30(/). Theoretical calculations in the ground state have been carried out for the compound studied using the Hartree-Fock (HF) and density functional theory (DFT) (B3LYP) with 6-31G(d,p) basis sets. The results show that the studied compound prefers the keto form. The compound involves intra- and intermolecular hydrogen bonding of C-H.-.O and C-H-..F types, which further stabilize the structure and display a trans configuration for the C=N and C=C double bonds. The calculated results show that the predicted geometry can well reproduce the structural parameters. 相似文献