- Blue and white light electroluminescence in a multilayer OLED using a new aluminium complex
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Synthesis, structure, optical absorption, emission and electroluminescence properties of a new blue emitting Al complex, namely, bis-(2-amino-8- hydroxyquinolinato), acetylacetonato Al(III) are reported. Multilayer OLED using the Al complex showed blue emission at 465 nm, maximum brightness of ～ 425 cd/m2 and maximum current efficiency of 0.16 cd/A. Another multilayer OLED using the Al complex doped with phosphorescent Ir complex showed 'white' light emission, CIE coordinate (0.41, 0.35), maximum brightness of ～ 970 cd/m2 and maximum current efficiency of 0.53 cd/A. Indian Academy of Sciences.
- Nayak, Pabitra K.,Agarwal, Neeraj,Ali, Farman,Patankar, Meghan P.,Narasimhan,Periasamy
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- Low-dimensional compounds containing bioactive ligands. Part XVI: Halogenated derivatives of 8-quinolinol N-oxides and their copper(II) complexes
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Four N-oxides, 8-quinolinol N-oxide (8-HQNO), 5,7-dichloro-8-quinolinol N-oxide (HdClQNO), 5,7-dibromo-8-quinolinol N-oxide (HdBrQNO) and 7-iodo-8-quinolinol N-oxide (HIQNO) as well as their six copper complexes, CuCl2(8-HQNO)2(H2O) (1), CuCl2(HdClQNO)2(H2O)2 (2), Cu(dClQNO)2(CHCl3) (3), Cu(dClQNO)2(H2O) (4), {[Cu(dBrQNO)2]?2H2O}n (5) and CuCl2(HIQNO)2(H2O)4 (6) were synthesised as possible anticancer agents. Crystal structures of N-oxides contain planar molecules held together via hydrogen bonds involving oxygen atoms of N-oxide groups as acceptors. Crystal structure of 5 represents the first structure of a copper(II) complex with an N-oxide ligand derived from 8-HQNO and is formed by infinite chains. In the chain, the Cu(II) atom coordinates to six oxygen atoms from two bidentate chelating dBrQNO ligands occupying apexes of elongated tetragonal bipyramid with bridging oxygen atoms of N-oxide groups in axial positions. Antiproliferative activity of prepared N-oxides as well as their complexes was studied using in vitro MTT assay against the MDA-MB-231, HCT-116 and A549 cancer cell lines and their selectivity was verified on MSCs cells. Among the tested cancer cell lines, A549 and MDA-MB-231 cells were the most sensitive to the tested complexes. Complex 1 showed the highest cytotoxicity against both tumor cell lines. At concentration, which could be tested in animal models, 1 induced cell death in more than 50% of cancer cells and in 20% of MSCs indicating its selectivity.
- Baran, Peter,Harmo?ová, Michaela,Ilic, Aleksandar,Lük?ová, Andrea,Litecká, Miroslava,Poto?ňák, Ivan,Vilková, Mária,Volarevic, Vladislav
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- SYNTHESIS OF LAVENDAMYCIN
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A regiospecific and convergent synthesis of Lavendamycin (1) starting from 8-hydroxyquinoline and indole via Bischler-Napieralski cyclisation is described.
- Rao, A. V. Rama,Chavan, Subhash P.,Sivadasan, Latha
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- Heterocyclic Aromatic N-Oxidation in the Biosynthesis of Phenazine Antibiotics from Lysobacter antibioticus
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Heterocyclic aromatic N-oxides often have potent biological activities, but the mechanism for aromatic N-oxidation is unclear. Six phenazine antibiotics were isolated from Lysobacter antibioticus OH13. A 10 gene cluster was identified for phenazine biosynthesis. Mutation of LaPhzNO1 abolished all N-oxides, while non-oxides markedly increased. LaPhzNO1 is homologous to Baeyer-Villiger flavoproteins but was shown to catazlye phenazine N-oxidation. LaPhzNO1 and LaPhzS together converted phenazine 1,6-dicarboxylic acid to 1,6-dihydroxyphenazine N5,N10-dioxide. LaPhzNO1 also catalyzed N-oxidation of 8-hydroxyquinoline.
- Zhao, Yangyang,Qian, Guoliang,Ye, Yonghao,Wright, Stephen,Chen, Haotong,Shen, Yuemao,Liu, Fengquan,Du, Liangcheng
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- Oxo-rhenium(V) complexes with 8-hydroxyquinoline derivatives
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Compounds of the types ReOCl2(L)(PPh3) and ReOCl(L)2 were prepared by reacting ReOCl3(PPh 3)2 with 8-hydroxyquinoline (HL) and its 2-methyl, 2-chloro, 5-chloro, 5-nitro, 5,7-dichloro, 5,7-dibromo, and 5,7-diiodo derivatives. With the bulky 2-phenyl-8-hydroxyquinoline, only ReOCl 2(L)(PPh3) could be isolated, whereas the still bulkier 2-tert-butyl derivative did not react. For ReOCl2(L)(PPh 3), the coordination of the quinoline oxygen trans to the Re=O bond and the cis-dichloro arrangement in the equatorial plane were established from crystallographic studies on the 2-chloro and the 5,7-dibromo complexes. From the combined data for these various derivatives, the 1H NMR signals could be fully assigned. With both series of compounds, a complex d-d absorption pattern is observed in the visible spectra, corresponding to the excitation of a d electron from the interaxial d orbital in the equatorial plane to the empty dxz and dyz orbitals, which are inequivalent in these low-symmetry systems. Deconvolution revealed the presence of two very weak low-energy components (～10 000 and ～12 000 cm-1), which are assigned to the two expected singlet-triplet transitions, whereas two stronger bands at higher energy (～14 000 and ～17 000 cm-1) originate from the two singlet-singlet transitions. These bands are not substantially displaced by substitution on the 8-hydroxyquinoline rings.
- Sigouin, Olivier,Beauchamp, Andre L.
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- Synthesis and evaluation of radioiodinated 1-{2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinolin-8-yl}piperidin-4-amine derivatives for platelet-derived growth factor receptor β (PDGFRβ) imaging
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Platelet-derived growth factor receptor β (PDGFRβ) is a transmembrane tyrosine kinase receptor and it is upregulated in various malignant tumors. Radiolabeled PDGFRβ inhibitors can be a convenient tool for the imaging of tumors overexpressing PDGFRβ. In this study, [125I]-1-{5-iodo-2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinoline-8-yl}piperidin-4-amine ([125I]IIQP) and [125I]-N-3-iodobenzoyl-1-{2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinolin-8-yl}-piperidin-4-amine ([125I]IB-IQP) were designed and synthesized, and their potential as PDGFRβ imaging agents was evaluated. In cellular uptake experiments, [125I]IIQP and [125I]IB-IQP showed higher uptake by PDGFRβ-positive cells than by PDGFRβ-negative cells, and the uptake in PDGFRβ-positive cells was inhibited by co-culture with PDGFRβ ligands. The biodistribution of both radiotracers in normal mice exhibited hepatobiliary excretion as the main route. In mice inoculated with BxPC3-luc (PDGFRβ-positive), the tumor uptake of radioactivity at 1 h after the injection of [125I]IIQP was significantly higher than that after the injection of [125I]IB-IQP. These results indicated that [125I]IIQP can be a suitable PDGFRβ imaging agent. However, further modification of its structure will be required to obtain a more appropriate PDGFRβ-targeted imaging agent with a higher signal/noise ratio.
- Effendi, Nurmaya,Ogawa, Kazuma,Mishiro, Kenji,Takarada, Takeshi,Yamada, Daisuke,Kitamura, Yoji,Shiba, Kazuhiro,Maeda, Takehiko,Odani, Akira
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- Palladium-catalyzed alkenylation of quinoline-N-oxides via C-H activation under external-oxidant-free conditions
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(Chemical Equation Presented) The direct cross-coupling of quinoline-N-oxides with olefin derivatives has been realized using palladium acetate as the catalyst in the absence of external ligand and oxidant to give the corresponding 2-alkenylated quinolines and 1-alkenylated isoquinolines chemo- and regioselectively in 27-95% yield. The catalytic process is proposed to proceed via direct C-H bond activation of the quinoline-N-oxide with Pd(OAc)2 followed by Heck coupling with the olefin. The resultant N-oxide of the alkenylated quinoline can oxidize the reduced Pd(0) to regenerate the Pd(II) active species and simultaneously release the 2-alkenylated quinoline without using any external oxidants and reductants.
- Wu, Junliang,Cui, Xiuling,Chen, Lianmei,Jiang, Guojie,Wu, Yangjie
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- Site-specific tagging proteins with a rigid, small and stable transition metal chelator, 8-hydroxyquinoline, for paramagnetic NMR analysis
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Design of a paramagnetic metal binding motif in a protein is a valuable way for understanding the function, dynamics and interactions of a protein by paramagnetic NMR spectroscopy. Several strategies have been proposed to site-specifically tag proteins with paramagnetic lanthanide ions. Here we report a simple approach of engineering a transition metal binding motif via site-specific labelling of a protein with 2-vinyl-8-hydroxyquinoline (2V-8HQ). The protein-2V-8HQ adduct forms a stable complex with transition metal ions, Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). The paramagnetic effects generated by these transition metal ions were evaluated by NMR spectroscopy. We show that 2V-8HQ is a rigid and stable transition metal binding tag. The coordination of the metal ion can be assisted by protein sidechains. More importantly, tunable paramagnetic tensors are simply obtained in an α-helix that possesses solvent exposed residues in positions i and i + 3, where i is the residue to be mutated to cysteine, i + 3 is Gln or Glu or i - 4 is His. The coordination of a sidechain carboxylate/amide or imidazole to cobalt(II) results in different structural geometries, leading to different paramagnetic tensors as shown by experimental data.
- Yang, Yin,Huang, Feng,Huber, Thomas,Su, Xun-Cheng
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- SYNTHESIS OF A NOVEL HEXADENTATE CHELATING AGENT BASED ON 8-HYDROXYQUINOLINE
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A new hexadentate chelator was synthesized by the functionalization of 8-hydroxyquinoline to its 2-carboxy-N-hydroxysuccinimidyl ester and a subsequent condensation with tris(2-aminoethyl)amine to give tris-N-(2-aminoethyl-)amine.This molecule is a siderophore analog with a non-naturally occurring binding unit comprising a combination of both oxygen and nitrogen donor atoms.
- Shrader, William D.,Celebuski, Joseph,Kline, Steven J.,Johnson, David
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- First safe and practical synthesis of 2-amino-8-hydroxyquinoline
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The first safe and efficient synthesis of the important building block 2-amino-8-hydroxyquinoline (1) is described. Starting from the readily available N-oxide 3 of the cheap bulk chemical 8-hydroxyquinoline (2), the target compound is obtained in a two-step one pot procedure in good overall yield (53-66%) and purity (>98%) on a kilogram scale without chromatography.
- Storz, Thomas,Marti, Roger,Meier, Roland,Nury, Patrice,Roeder, Michael,Zhang, Kesheng
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- Hydrazo coupling: The efficient transition-metal-free C-H functionalization of 8-hydroxyquinoline and phenol through base catalysis
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Azodicarboxylate esters are common reagents in organic synthesis laboratories due to their utility in the Mitsunobu reaction. They can also be regarded as possible starting compounds for C-H functionalization, which up until now has been mainly achieved by transition-metal-catalyzed reactions. We have developed a novel reaction involving the quantitative coupling of 8-hydroxyquinoline or phenol with azodicarboxylate esters. The functionalization proceeds under mild base-catalyzed conditions selectively, and either the ortho-position of 8-hydroxyquinoline or para-position of the phenol/naphthol is involved in the reaction. This type of transformation can be considered as "hydrazo coupling" (by analogy with azo coupling). Herein, we discuss a plausible mechanism for this catalyzed substitution, backing up our findings with deuterium NMR experiments and by varying the starting compounds and bases. Using Boc-NN-Boc as a substrate, we have developed the convenient and efficient synthesis of (8-hydroxyquinolin-7-yl)hydrazines, as well as demonstrating a new stereoselective route for the synthesis of medicinally important 4-hydroxyphenylhydrazine for laboratory use, which almost doubles the yield of the common industrial process and reduces the number of synthetic steps. A new "one-pot" procedure for the synthesis of aromatic 8-hydroxyquinolin-7-yl hydrazones was applied.
- Solyev, Pavel N.,Sherman, Daria K.,Novikov, Roman A.,Levina, Eugenia A.,Kochetkov, Sergey N.
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- Allyltin tribromide: A versatile reagent involved in the ring-opening of epoxides
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This paper presents a versatile reagent for epoxide cleavage. The allyltin tribromide could act as a novel and easily prepared allylation reagent and halide atom donor to convert epoxides to the corresponding homoallyl alcohols and halohydrins in high yields with excellent regioselectivities under mild reaction conditions, respectively. It could also act as a Lewis acid to catalyze the ring opening reactions of epoxides with alcohols.
- Chen, Guohong,Wang, Xin,Jin, Xiaoqian,Liu, Lingyan,Chang, Weixing,Li, Jing
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- Synthesis of 2-Alkenylquinoline by Reductive Olefination of Quinoline N-Oxide under Metal-Free Conditions
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Synthesis of 2-alkenylquinoline by reductive olefination of quinoline N-oxide under metal-free conditions is disclosed. Practically, the reaction could be performed with quinoline as starting material via a one-pot, two-step process. A possible mechanism is proposed that involves a sequential 1,3-dipolar cycloaddition and acid-assisted ring opening followed by a dehydration process.
- Xia, Hong,Liu, Yuanhong,Zhao, Peng,Gou, Shaohua,Wang, Jun
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- Waste-minimized synthesis of C2 functionalized quinolines exploiting iron-catalysed C-H activation
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Herein we present an efficient and regioselective iron-catalyzed methodology for the external oxidant-free functionalization of quinoline-N-oxides. The protocol, based on the use of inexpensive and easily accessible FeSO4, showed broad applicability to a wide range of substrates. An additional green feature of this synthetic methodology is H2O being the only by-product. Experimental and computational investigations provide support to a mechanism based on a facile C-H activation event. The green efficiency of the process has also been carefully assessed using: (i) metrics related to the synthetic process (AE, Yield, 1/SF, MRP and RME); (ii) safety/hazard metrics (SHZI and SHI); and (iii) metrics related to the metal used as the catalyst (Abundance, OEL and ADP). In addition to the many advantages of this protocol related to the green iron catalyst used and the safety/hazard features of the process, an E-factor value of ca. 0.92 (84 to >99% reduction compared to known protocols) evidently confirms the sustainable efficiency of the procedure presented. Practical utility has also been demonstrated by performing the reaction efficiently on a multi-gram scale. This journal is
- Ferlin, Francesco,Zangarelli, Agnese,Lilli, Simone,Santoro, Stefano,Vaccaro, Luigi
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supporting information
p. 490 - 495
(2021/01/28)
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- O-prenylated carbostyrils as a novel class of 15-lipoxygenase inhibitors: Synthesis, characterization, and inhibitory assessment
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Catalyzed peroxidation of unsaturated lipid in animals and plants intimately is linked to the activity of 15-Lipoxygenase enzymes. Lipoxygenases (LOXs) are well known to play an important role in many acute and chronic syndromes such as inflammation, asthma, cancer, and allergy. In this study, a series of mono prenyloxycarbostyrils were synthesized and evaluated as potential inhibitors of soybean 15-Lipoxygenase (SLO) and their inhibitory potencies were compared to mono prenyloxycoumarins which had been reported in the previous works. The synthetic compounds inhibit lipoxygenase enzyme by competitive mechanism like the prenyloxy coumarins. The results showed that position and length of the prenyl moiety play the important role in lipoxygenase inhibitory activity. Among all of the synthetic compounds (coumarin and carbostyril derivatives), 5-farnesyloxycoumarin and 8-farnesyloxycarbostyril demonstrated the best inhibitory activity by IC50?values of 1.1?μM and 0.53?μM, respectively.
- Alavi, Seyed Jamal,Zebarjadi, Amir,Bafghi, Mahdi Hosseini,Orafai, Hossein,Sadeghian, Hamid
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p. 894 - 902
(2021/09/08)
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- The M?CPbA?NH3(G) system: A safe and scalable alternative for the manufacture of (substituted) pyridine and quinoline N?oxides?
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An improved, safe, and scalable isolation process for (substituted) pyridine and quinoline N-oxides in quantitative yields along with high purities using the m-CPBA?NH3(g) system is described. The safety was assessed by reaction calorimetry and differential scanning calorimetry studies for possible hazards during the conversion and isolation steps. Careful interpretation of the data substantiated the safety and scalability. The process flow is simplified to meet the industrial requirements of safety, cost-effectiveness, and utility minimization. The reaction was safely demonstrated at a 2.5 kg scale.
- Palav, Amey,Misal, Balu,Ernolla, Anilkumar,Parab, Vinod,Waske, Prashant,Khandekar, Dileep,Chaudhary, Vinay,Chaturbhuj, Ganesh
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supporting information
p. 244 - 251
(2019/03/17)
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- Method for preparing azaheterocycle-N-oxides
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The invention relates to a method for preparing azaheterocycle-N-oxides. The method is concretely characterized in that pyridine, quinoline and isoquinoline compounds, which are used as raw materials,are oxidized under the action of a catalyst to obtain the corresponding N-oxides. The method for preparing azaheterocycle-N-oxides is a preparation method having the advantages of high yield, low cost, easiness in operation, and suitableness for industrialization.
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Paragraph 0022-0023; 0024-0025; 0026-0027; 0028-0029
(2019/09/14)
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- Hypervalent Iodine(III)-Mediated Regioselective Cyanation of Quinoline N-Oxides with Trimethylsilyl Cyanide
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A regioselective cyanation of quinoline N-oxides with trimethylsilyl cyanide was developed by using (Diacetoxyiodo) benzene (PIDA) as mediated hypervalent iodine(III) reagent under metal-free and base-free reaction conditions to obtain 2-cyanoquinolines. The efficient PIDA reagent could play the role of an activator of the substrates and an accelerator of N?O bond cleavage. The reaction system featured a wide range of substrate suitability and high yields. The procedure was enlarged gram-scale to synthesize the tuberculosis (TB) inhibitor. Finally, according to some experimental results, a plausible mechanism for the cyanation reaction is proposed. (Figure presented.).
- Xu, Feng,Li, Yuqin,Huang, Xin,Fang, Xinjie,Li, Zhuofei,Jiang, Hongshuo,Qiao, Jingyi,Chu, Wenyi,Sun, Zhizhong
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supporting information
p. 520 - 525
(2018/12/13)
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- Discovery of β-arrestin-biased β2-adrenoceptor agonists from 2-amino-2-phenylethanol derivatives
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β-Arrestins are a small family of proteins important for signal transduction at G protein-coupled receptors (GPCRs). β-Arrestins are involved in the desensitization of GPCRs. Recently, biased ligands possessing different efficacies in activating the G protein- versus the β-arrestin-dependent signals downstream of a single GPCR have emerged, which can be used to selectively modulate GPCR signal transduction in such a way that desirable signals are enhanced to produce therapeutic effects while undesirable signals of the same GPCR are suppressed to avoid side effects. In the present study, we evaluated agonist bias for compounds developed along a drug discovery project of β2-adrenoceptor agonists. About 150 compounds, including derivatives of fenoterol, 2-amino-1-phenylethanol and 2-amino-2-phenylethanol, were obtained or synthesized, and initially screened for their β-adrenoceptor-mediated activities in the guinea pig tracheal smooth muscle relaxation assay or the cardiomyocyte contractility assay. Nineteen bioactive compounds were further assessed using both the HTRF cAMP assay and the PathHunter β-arrestin assay. Their concentration-response data in stimulating cAMP synthesis and β-arrestin recruitment were applied to the Black–Leff operational model for ligand bias quantitation. As a result, three compounds (L-2, L-4, and L-12) with the core structure of 5-(1-amino-2-hydroxyethyl)-8-hydroxyquinolin-2(1H)-one were identified as a new series of β-arrestin-biased β2-adrenoceptor agonists, whereas salmeterol was found to be Gs-biased. These findings would facilitate the development of novel drugs for the treatment of both heart failure and asthma.
- Woo, Anthony Yiu-Ho,Ge, Xin-yue,Pan, Li,Xing, Gang,Mo, Yong-mei,Xing, Rui-juan,Li, Xiao-ran,Zhang, Yu-yang,Wainer, Irving W.,Cheng, Mao-sheng,Xiao, Rui-ping
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p. 1095 - 1105
(2019/01/19)
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- Regioselective Cyanation of Six-Membered N-Heteroaromatic Compounds Under Metal-, Activator-, Base- and Solvent-Free Conditions
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A regioselective cyanation of heteroaromatic N-oxides with trimethylsilyl cyanide has been developed to obtain 2-substituted N-heteroaromatic nitrile without the requirement of any external activator-, metal-, base-, and solvent. The present protocol is a straightforward, one-pot heteroaromatic C?H cyanation process, and proceeds smoothly in conventional heating but also under microwave irradiation with shorter reaction times. This approach now allows access to a broad class of quinoline N-oxides and other heteroarene N-oxides with high to good yields and can also be scaled up to obtain gram quantities. Further application of this process was observed and utilized in late-stage cyanation of the anti-malarial drug quinine as well as transformation of the 2-cyanoazines to a series of biologically important molecules. Based on the experimental observations, a plausible mechanism has also been proposed highlighting the dual role of trimethylsilyl cyanide as a nitrile source and as an activating agent. (Figure presented.).
- Sarmah, Bikash Kumar,Konwar, Monuranjan,Bhattacharyya, Dipanjan,Adhikari, Priyanka,Das, Animesh
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supporting information
p. 5616 - 5625
(2019/11/22)
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- A mild and efficient H2O2 oxygenation of N-heteroaromatic compounds to the amine N-oxides and KI deoxygenation back to the tertiary amine with hexaphenyloxodiphosphonium triflate
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A mild and efficient method for the oxidation of N-heteroaromatic compounds to the corresponding N-oxides using H2O2 in the presence of hexaphenyloxodiphosphnium triflate (Hendrickson reagent) in EtOH at room temperature was reported. This methodology presented relatively fast and selective reactions to afford the N-oxides in good yields. The reverse reactions, deoxygenation reactions, were also carried out under the same reaction conditions by KI to produce the tertiary amines.
- Khodaei, Mohammad Mehdi,Alizadeh, Abdolhamid,Hezarkhani, Hadis Afshar
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p. 1843 - 1849
(2018/07/06)
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- Method for synthesizing quinoline oxynitride from quinoline compound by ultrasonic-assisted oxidation
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The invention discloses a method for synthesizing quinoline oxynitride from a quinoline compound by ultrasonic-assisted oxidation. The quinoline compound and hydrogen peroxide are subjected to nitrogen oxidation reaction under the ultrasonic-assisted condition and perfluorosulfonic acid resin (Nafion-H) catalytic action to obtain quinoline oxynitride. The method has the advantages that the raw materials are easy to obtain, reaction conditions are simple and mild, greenness and energy conservation are achieved, and reaction selectivity and yield are high; energy is saved and the compatibility of substrate functional groups is excellent; in particular, the perfluorosulfonic acid resin can be recycled as an acid catalyst, so that not only is the reaction cost reduce, but also the reaction yield is increased, also the pollution problem in traditional oxidation reaction is avoided and a relatively high application value is achieved.
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Paragraph 0082; 0083; 0084
(2018/06/21)
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- Transition-Metal-Free Regioselective Alkylation of Quinoline N-Oxides via Oxidative Alkyl Migration and C?C Bond Cleavage of tert-/sec-Alcohols
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An unprecedented C2-alkylation of quinoline N-oxide derivatives via C?C bond activation of tert- and sec-alkyl alcohol is described using hypervalent iodine (III) reagent PhI(OAc)2 (PIDA). This regioselective alkylation using mild hypervalent iodine reagents is more practical, operationally simple and transition metal free. The reaction proceeds efficiently with a broad range of substrates including quinoline, isoquinoline, and pyridine N-oxides using a variety of tert-/sec- alcohols. From experimental outcome, we also propose a rationalized mechanism, mediated by PIDA. (Figure presented.).
- Sen, Chiranjit,Ghosh, Subhash C.
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supporting information
p. 905 - 910
(2018/01/11)
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- Oxidative Cleavage of Styrenes Catalyzed by a PdIIComplex of an 8-Hydroxyquinolinonate Ligand
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Synthesis and catalytic activity of palladium complexes of 8-(pyridin-2-ylmethoxy)quinolinone (3) were investigated. Complexation of 3 with [Pd(CH3CN)2Cl2] gave the dimeric palladium complex [{N,N-(3)PdCl}2] (4). The structure of 4 was characterized by1H/13C NMR spectroscopy and mass spectrometry, and further confirmed by X-ray crystallography. Complex 4 acts as a catalyst for oxidative cleavage of C=C bonds, and it catalyzes the hydration of styrenes in an anti-Markovnikov Wacker manner to give terminal aldehydes as the initial product, which then undergo C–C cleavage to yield the corresponding benzaldehydes. Systematic studies of this catalysis were performed.
- Jhong, Hong-Ming,Liu, Yi-Hung,Peng, Shie-Ming,Liu, Shiuh-Tzung
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p. 5449 - 5455
(2016/12/16)
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- Regioselective Chlorination of Quinoline N-Oxides and Isoquinoline N-Oxides Using PPh3/Cl3CCN
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A novel method for the regioselective C2-chlorination of heterocyclic N-oxides has been developed. PPh3/Cl3CCN were used as chlorinating reagents and the desired N-heterocyclic chlorides were obtained smoothly in satisfactory yields. The reactions proceeded in a highly efficient and selective manner across a broad range of substrates demonstrating excellent functional group tolerance. In addition, this chlorination reaction can be used for the modification of N-heterocyclic scaffolds of appealing ligands and pharmaceuticals.
- Qiao, Kai,Wan, Li,Sun, Xiaoning,Zhang, Kai,Zhu, Ning,Li, Xin,Guo, Kai
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p. 1606 - 1611
(2016/04/05)
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- A lipase-glucose oxidase system for the efficient oxidation of: N -heteroaromatic compounds and tertiary amines
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In this work, a lipase-glucose oxidase system has been designed and proven to be an efficient system for the oxidation of N-heteroaromatic compounds and tertiary amines. This dual-enzyme system not only displays environmental friendliness, but also demonstrates its huge potential in industrial applications.
- Yang, Fengjuan,Zhang, Xiaowen,Li, Fengxi,Wang, Zhi,Wang, Lei
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supporting information
p. 3518 - 3521
(2016/07/06)
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- Base free regioselective synthesis of α-triazolylazine derivatives
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A regioselective α-heteroarylation followed by deoxygenation towards the synthesis of variety of azine triazole from simple azine N-oxides derivatives and N-tosyl-1,2,3-triazoles has been described. The reaction is metal free and base free with shorter reaction time, high yields and a broad substrate scope.
- Harisha, Mysore Bhyrappa,Nagaraj, Muthupandi,Muthusubramanian, Shanmugam,Bhuvanesh, Nattamai
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p. 58118 - 58124
(2016/07/06)
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- Synthesis and evaluation of 8-hydroxyquinolin derivatives substituted with (benzo[d][1,2]selenazol-3(2H)-one) as effective inhibitor of metal-induced Aβ aggregation and antioxidant
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A series of 8-hydroxyquinolin derivatives substituted with (benzo[d][1,2]selenazol-3(2H)-one) at the 2-position were synthesized and evaluated for treatment of Alzheimer's disease. In vitro assays demonstrated that most of the target compounds exhibit significant inhibition of Cu(II)-induced Aβ1–42aggregation, rapid H2O2scavenging and glutathione peroxidise (GPx)-like catalytic activity. Among these molecules, compound 9a is the most potent peroxide scavenger that possesses the ability to scavenge most H2O2within 200–220 min and possesses GPx-like activity (v0= 106.0 μM·min?1), enabling modulation of metal-induced Aβ aggregation.
- Wang, Bo,Wang, Zhiren,Chen, Hong,Lu, Chuan-Jun,Li, Xingshu
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p. 4741 - 4749
(2016/09/09)
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- Facile Immobilization of a Lewis Acid Polyoxometalate onto Layered Double Hydroxides for Highly Efficient N-Oxidation of Pyridine-Based Derivatives and Denitrogenation
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N-Oxides are a class of highly important compounds that are used widely as synthetic intermediates. In this paper, we demonstrate for the first time the use of a polyoxometalate-based composite material as a highly efficient heterogeneous catalyst for the N-oxidation of pyridines and its derivatives in the presence of H2O2 at room temperature. The composite was prepared by the intercalation of the [La(PW11O39)2]11- anion into a layered double hydroxide (LDH) modified with tris(hydroxymethyl)aminomethane (Tris). Additionally, the Tris-LDH-La(PW11)2-based catalyst has been employed for the denitrogenation of a model oil mixture in the presence of 1-butyl-3-methylimidazolium tetrafluoroborate and H2O2. Denitrogenation can be achieved in 40 min at 75 C. Finally, the heterogeneous catalyst can be recovered easily and reused at least 10 times without a measurable decrease of the catalytic activity and disintegration of the Tris-LDH-La(PW11)2 structure. Between the sheets: We demonstrate for the first time the use of a polyoxometalate-based composite material as a highly efficient heterogeneous catalyst for the N-oxidation of pyridines and its derivatives in the presence of H2O2 at room temperature. The composite is prepared by the intercalation of the [La(PW11O39)2]11- anion into a layered double hydroxide modified with tris(hydroxymethyl)aminomethane.
- Liu, Kai,Yao, Zhixiao,Miras, Haralampos N.,Song, Yu-Fei
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p. 3903 - 3910
(2016/01/26)
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- Catalytic system for pyridine oxidation to N-oxides under mild conditions based on polyoxomolybdate
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A reusable and effective catalytic system has been developed for oxidation of pyridines catalyzed by Keplerate polyoxomolybdate ({Mo132}) at room temperature. Pyridine compounds could be oxidized in high yields under mild conditions.
- Yang, Chunxia,Zhao, Wei,Cheng, Zhiguo,Luo, Baomin,Bi, Dongqin
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p. 36809 - 36812
(2015/05/05)
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- METHOD FOR PRODUCING LINEAR AND/OR CYCLIC CARBONATE ESTERS
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The present invention relates to a method for producing linear and/or cyclic carbonate esters, involving the step of reacting an epoxide with carbon dioxide in the presence of a catalyser. The invention further relates to the use of special catalysers for reacting epoxides with carbon dioxide, special catalysers and special reaction products. The catalyser comprises a complex of a metal M or M-A with a ligand L, the metal M being present in an oxidation state of >=0, A standing for halide, carboxylate, phenolate, sulfonate, phosphonate, alkyl, alkoxy or amido, and the ligand L having the subsequent structure (Ia) or (Ib), wherein one or both of the OH groups shown in (Ia) and/or (Ib) can also be deprotonated.
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Paragraph 0093-0098
(2015/07/27)
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- METHOD FOR PRODUCING LINEAR AND/OR CYCLIC CARBONATE ESTERS
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Preparing linear and/or cyclic carbonate ester, comprises reacting an epoxide with carbon dioxide in the presence of a catalyst. The catalyst comprises a metal complex (IIa) or (IIb) with a ligand (IIc). The metal (IIa) is present in an oxidation state of >= 0. Preparing linear and/or cyclic carbonate ester, comprises reacting an epoxide with carbon dioxide in the presence of a catalyst. The catalyst comprises a metal complex of formula (M) (IIa) or (MA) (IIb) with a ligand of formula (L) (Iic). The metal (IIa) is present in an oxidation state of >= 0. A : halo, carboxylate, phenoxide, sulfonate, phosphonate, alkyl, alkoxy or amido; L : (Ia) or (Ib), where OH groups may be deprotonated; R1-R4 : H, 1-22C alkyl, 5-12C cycloalkyl, 7-14C aralkyl or 7-14C alkylaryl or 6-14C aryl; X : amine moiety of formula (II) or alkane moiety of formula (III); R5 : 1-22C alkyl, 5-12C cycloalkyl, 7-14C aralkyl, or 7-14C alkylaryl, 6-14C aryl, or optionally alkyl-substituted pyridyl or pyridylmethyl; R6, R7 : H, 1-22C alkyl, 5-12C cycloalkyl, 7-C14-aralkyl or alkylaryl, 6-14C aryl or -COOR8; and R8 : 1-8C alkyl. Independent claims are also included for: (1) the polymeric carbonate ester, which is obtained by the reaction of cyclic epoxide with carbon dioxide by the above mentioned method, where the number average molecular weight of polymeric carbonate ester determined by gel permeation chromatography is >= 500 g/mole to = 5000 g/mole and the polydispersity index is >= 1 to = 1.5; and (2) a metal complex of formula (XIX) or (XX). M1 : Cr(III)-A, Co(III)-A or Zn(II). [Image] [Image] [Image].
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Paragraph 0124-0127
(2016/11/17)
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- Insights into the mechanistic and synthetic aspects of the Mo/P-catalyzed oxidation of N-heterocycles
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A Mo/P catalytic system for an efficient gram-scale oxidation of a variety of nitrogen heterocycles to N-oxides with hydrogen peroxide as terminal oxidant has been investigated. Combined spectroscopic and crystallographic studies point to the tetranuclear Mo4P peroxo complex as one of the active catalytic species present in the solution. Based on this finding an optimized catalytic system has been developed. The utility and chemoselectivity of the catalytic system has been demonstrated by the synthesis of over 20 heterocyclic N-oxides.
- Larionov, Oleg V.,Stephens, David,Mfuh, Adelphe M.,Arman, Hadi D.,Naumova, Anastasia S.,Chavez, Gabriel,Skenderi, Behije
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p. 3026 - 3036
(2014/05/06)
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- The oxidation of pyridines catalyzed by surfactant-encapsulated polyoxometalate [(C18H37)2(CH3) 2N]8[HBW11O39] with the temperature-responsive property of solubility
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Temperature-responsive characterization of solubility based on a surfactant-encapsulated polyoxometalate ([(C18H37) 2(CH3)2N]8[HBW11O 39]) in tert-butyl alcohol was described and used in catalytic oxidation of pyridines. The catalyst could be recovered and reused several times by controlling the temperature.
- Zhao, Wei,Yang, Chunxia,Ding, Yong,Ma, Baochun
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p. 2614 - 2618
(2013/09/12)
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- HETEROARYL COMPOUNDS AND METHODS OF USE THEREOF
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Provided herein are heteroaryl compounds, methods of their synthesis, pharmaceutical compositions comprising the compounds, and methods of their use. In one embodiment, the compounds provided herein are useful for the treatment, prevention, and/or management of various disorders, such as CNS disorders and neurological disorders, including, but not limited to, e.g., psychosis, schizophrenia, depression, movement disorders, and Parkinson's disease.
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Paragraph 00265; 00266
(2013/12/03)
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- QUATERNARY AMMONIUM SALT COMPOUNDS
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[Problem] The object of the present invention is to provide a novel compound having 132 adrenergic receptor agonist activity and muscarinic receptor antagonist activity. [Means for Solving the Problem] The present invention is a quaternary ammonium salt compounds represented by formula (I), or a pharmaceutically acceptable salt thereof, with superior β32 adrenergic receptor agonist activity and muscarinic receptor antagonist activity.
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Page/Page column 19
(2012/03/10)
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- New ligands that promote cross-coupling reactions between aryl halides and unactivated arenes
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Several ligands were designed to promote transition-metal-free cross-coupling reactions of aryl halides with benzene derivatives. Among the systems probed, quinoline-1-amino-2-carboxylic acid was found to serve as an excellent catalyst for cross-coupling between aryl halides and unactivated benzene. Reactions using this inexpensive catalytic system displayed a high functional group tolerance as well as excellent chemoselectivities.
- Qiu, Yatao,Liu, Yanghan,Yang, Kai,Hong, Wenkun,Li, Zheng,Wang, Zhaoyang,Yao, Zhiyi,Jiang, Sheng
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supporting information; experimental part
p. 3556 - 3559
(2011/09/14)
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- The oxidation of pyridine and alcohol using the Keggin-type lacunary polytungstophosphate as a temperature-controlled phase transfer catalyst
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A novel temperature-controlled phase transfer catalyst of [(C 18H37)2(CH3)2N] 7[PW11O39] has been developed for the oxidation of pyridines and alcohols with hydrogen peroxide. The reactions were conducted in 1,4-dioxane, and high yields of the corresponding heterocyclic N-oxides and ketones were obtained under relative mild conditions. The catalyst could be easily recovered and reused after reaction with cooling. There was no discernable loss in activity and selectivity after several reaction cycles.
- Ding, Yong,Zhao, Wei
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experimental part
p. 45 - 51
(2011/04/24)
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- Ligands for copper-catalyzed C-N bond forming reactions with 1 Mol% CuBr as catalyst
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Several new ligands were designed to promote copper-catalyzed Ullman C-N coupling reactions. In this group, 8-hydroxyquinolin-N-oxide was found to serve as a superior ligand for CuBr-catalyzed coupling reactions of aryl iodides, bromides, and chlorides with aliphatic amines and N-heterocycles under a low catalyst loading (1% [Cu] mol). Reactions with the inexpensive catalytic system display a high functional group tolerance as well as excellent chemoselectivity.
- Yang, Kai,Qiu, Yatao,Li, Zheng,Wang, Zhaoyang,Jiang, Sheng
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experimental part
p. 3151 - 3159
(2011/06/23)
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- The Hiratani-double-Claisen rearrangement as a key step in the preparation of sequential bis(8-hydroxyquinoline) ligands
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Symmetric and sequential isobutenylidene-bridged bis-(8-hydroxyquinoline)s are prepared by application of the Hiratani-double-Claisen rearrangement as a key step in the reaction sequence. The formation of a dinuclear helicate-type zinc(II) complex is also described. Georg Thieme Verlag Stuttgart.
- Albrecht, Markus,Osetska, Olga,Fr?hlich, Roland
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p. 924 - 926
(2007/10/03)
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- Silica-supported vanadium-catalyzed N-oxidation of tertiary amines with aqueous hydrogen peroxide
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A recyclable silica supported vanadium 1 catalyzes the oxidation of tertiray amines to the corresponding N-oxides with 30% H2O 2 in high yield.
- Rout, Laxmidhar,Punniyamurthy, Tharmalingam
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p. 1958 - 1960
(2007/10/03)
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- Ion-triggered multistate molecular switching device based on regioselective coordination-controlled ion binding
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Molecular devices capable of accessing different controlled conformational states, while optically signaling the occupied state, are attractive tools for nanotechnology since they relate to both areas of molecular mechanical devices and logic gates. We report here a simple molecular system that allows access to four distinct conformational and optical states. It is based on the regioselective complexation of metal ions to a heterocyclic ligand triad, which is dictated by the accessible coordination geometry and electrostatic properties of two distinct binding subunits. Thus, local conformational switching is brought about by tetrahedral coordination (of CuI) or octahedral coordination (of M2+ ions) to bidentate and tridentate binding subunits, respectively. The shape modifications undergone represent an ion-controlled nanomechanical device. They give controlled access to four different states that display different physico-chemical (e.g. optical) properties and provide a basis for logic gate operations.
- Petitjean, Anne,Kyritsakas, Nathalie,Lehn, Jean-Marie
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p. 6818 - 6828
(2007/10/03)
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- Aqueous biphasic oxidation: A water-soluble polyoxometalate catalyst for selective oxidation of various functional groups with hydrogen peroxide
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A "sandwich" type polyoxometalate, Na12[(WZn 3(H2O)2][(ZnW9O34) 2], was used as an oxidation catalyst in aqueous biphasic reaction media to effect oxidation of alcohols, diols, pyridine derivatives, amines and aniline derivatives with hydrogen peroxide. The catalyst was shown by 183W NMR to be stable in aqueous solutions in the presence of H 2O2 and showed only minimal non-productive decomposition of the oxidant. Secondary alcohols were selectively oxidized to ketones, while primary alcohols tended to be oxidized to the corresponding carboxylic acids, although secondary alcohols were selectively oxidized in the presence of primary alcohols. Vicinal diols yielded carbon-carbon bond cleavage products in very high yields. Pyridine derivatives were oxidized to the respective TV-oxides, but strongly electron-withdrawing moieties inhibited the oxidation reaction. Primary amines were oxidized to the oximes, but significantly hydrolyzed in situ. Aniline derivatives were oxidized to the corresponding azoxy or nitro products depending on the substitution pattern in the aromatic ring. Catalyst recovery and recycle was demonstrated.
- Sloboda-Rozner, Dorit,Witte, Peter,Alsters, Paul L.,Neumann, Ronny
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p. 339 - 345
(2007/10/03)
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- 2-Phenyl-quinoline derivatives, preparation method and therapeutic use thereof
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Compounds of general formula (I) 1in which: A represents a hydrogen atom or a hydroxyl, B represents a hydrogen atom or a C1-3 alkyl group, R1 represents a phenyl optionally substituted with a halogen, a hydroxyl, a C1-3 alkoxy, C1-3 alkyl, C1-3 fluoroalkyl or C1-2 perfluoroalkyl group, R2, R3 and R6, which may be identical or different, each represent a hydrogen atom, a halogen, a C1-6 alkyl or C2-6 alkenyl group, R4 and R5, which may be identical or different, each represent a hydrogen atom, a C1-6 alkyl, C2-6 alkenyl or C3-6 cycloalkyl group, or R4 and R5 together form a C2-6 alkylene or C3-6 alkenylene chain to give, with the nitrogen to which they are attached, a heterocycle, this heterocycle optionally being substituted with a C1-4 alkyl group. Therapeutic use.
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- 2-arylquinoline derivatives, preparation and therapeutic use thereof
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Compounds of general formula (I) in which: A represents a hydrogen atom, a hydroxyl, a C1-3alkoxy group, a hydroxy(C1-6alkyl) group, a (C1-3alkoxy)(C1-3alkyl) group, a thiol, (C1-6alkyl)sulfanyl or a halogen; B and D represent, independently of one another, a hydrogen atom, a C1-6alkyl group, a fluoro(C1-6alkyl) group or a perfluoro(C1-2alkyl) group or B and D together from an oxo; R1represents a phenyl, a naphthyl or a heteroaryl comprising 4 or 5 carbon atoms; R2and R3represent, independently of one another, a hydrogen atom, a halogen or a C1-6alkyl group, R4represents a hydrogen atom, a hydroxyl or a halogen, and R5and R6represent, independently of one another, a hydrogen atom, a C1-6alkyl group, a C2-6alkenyl group, a C3-6cycloalkyl group, a C3-6cycloalkenyl group, a fluoro(C1-6alkyl) group or a perfluoro(C1-2alkyl) group or R5and R6together form a C2-6alkylene chain or a C3-6alkenylene chain, to give, with the nitrogen to which they are attached, a heterocycle, this heterocycle optionally being substituted by a C1-4alkyl group; and their salts.
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- Phase-Vanishing Methodology for Efficient Bromination, Alkylation, Epoxidation, and Oxidation Reactions of Organic Substrates
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(Matrix presented) In cases where both reactants in a phase-vanishing reaction are less dense than the fluorous phase, an alternative to the U-tube method is to employ a solvent with greater density than the fluorous phase, such as 1,2-dibromoethane. This modification has been successfully applied to the methylation of a phenol derivative with dimethyl sulfate and to the m-CPBA-induced epoxidation of alkenes, N-oxide formation from nitrogen-containing compounds, and S-oxide or sulfone formation from organic sulfides.
- Jana, Nirmal K.,Verkade, John G.
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p. 3787 - 3790
(2007/10/03)
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- Oxidation of tertiary nitrogen compounds to N-oxides by molecular oxygen-aldehyde system in the absence of metal catalyst
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A variety of tertiary nitrogen compounds have been oxidized to corresponding N-oxides in near quantitative yields by molecular oxygen/2-methylpropanal system in the absence of metal catalyst.
- Dongre,Venkateshwar Rao,Sharma,Sain,Bhatia
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p. 167 - 172
(2007/10/03)
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- A new non-metal heterogeneous catalyst for the activation of hydrogen peroxide: A perfluorinated ketone attached to silica for oxidation of aromatic amines and alkenes
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A silane functionalized by octafluoroacetophenone was polymerized by the sol-gel method to form an insoluble silicate with perfluoroketone pendants; the silicate was used as a heterogeneous catalyst for the activation of aqueous hydrogen peroxide and the oxidation of aromatic amines and alkenes.
- Neimann,Neumann
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p. 487 - 488
(2007/10/03)
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- Structure-affinity profile of 8-hydroxycarbostyril-based agonists that dissociate slowly from the β2-adrenoceptor
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Several carbostyril-based β-agonists have been shown to bind tightly to and slowly dissociate from the β2-adrenoceptor (β2AR). In the present study, the structural features of 8-hydroxy-5-[2-[(1-phenyl-2-methylprop-2- yl)amino]-1-hydroxyethyl]-carbostyril (11a) which contribute to its binding properties at the β2AR were investigated using a series of synthesized analogs. The k(off), estimated by the rate of cAMP decline in DDT1 MF-2 (DDT) cells with a reduced receptor density, K(i) and ligand-induced receptor reductions were determined. All of the derivatives stimulated cAMP accumulation in DDT cells in the sub to mid nanomolar range and elicited the same maximal stimulation as (-)isoproterenol. Derivatives of 11a with side chain N-substitutions comprising 2-methylbutyl, phenylethyl and isopropyl had higher k(off)-values and lower affinities as compared to 11a. Increasing the number of methylenes between the side chain tertiary alpha carbon and phenyl from 1 in 11a to 3 or reducing the number to 0 also resulted in derivatives with higher k(off)- and K(i)-values). In addition, replacement of the 8- hydroxycarbostyril nucleus of 11a with catechol reduced the affinity of the compound for the β2AR by 48-fold and increased its k(off). Only those derivatives with the lowest k(off)-values induced a decrease in the receptor density of DDT cell membranes following a preincubation and extensive washing. The data show that the 8-hydroxycarbostyril nucleus in conjunction with substitutions on the tertiary alpha carbon of the side chain and positioning of the phenyl group are important characteristics determining the high affinity and slow dissociation of 11a from the β2AR.
- Deyrup,Nowicki,Richards,Otero,Harrison,Baker
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p. 168 - 177
(2007/10/03)
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- α-methylene-γ-butyrolactones: new inhibitors of platelet aggregation
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The present inventors have discovered three classes of novel α-methylene-γ-butyrolactones with excellent antiplatelet activity. As a result of intensive studies, it has been found that compounds represented by the formula I-III are potent inhibitors of platelet aggregation. STR1 For the formula I, R1 is a methyl, a phenyl group optionally substituted with one or two group selected from halide, (C1 -C4) alkyl, (C1 -C4) alkoxy, phenyl, nitro, amino. For the formula II, R1 is a methyl, a phenyl group optionally substituted with one or two group selected from halide, (C1 -C4) alkyl, (C1 -C4) alkoxy, phenyl, nitro, amino; R2 represents hydrogen, halide, (C1 -C4) alkyl, phenyl, nitro, amino; R3 represents hydrogen, halide, (C1 -C4) alkyl, phenyl, nitro, amino. For the formula III, R1 is a methyl, a phenyl group optionally substituted with one or two group selected from halide, (C1 -C4) alkyl, (C1 -C4) alkoxy, phenyl, nitro, amino; R4 represents hydrogen, hydroxy, (C1 -C4) alkyl. The present invention also provides a cost-efficient method for the preparation of formula I-III. Formula I-III may be administered orally or parenterly with an inert diluent or with a pharmaceutically acceptable carrier in the treatment or the prevention of cardiovascular disease.
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- 8-hydroxyquinoline chelating agents
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The present invention provides linear, cyclic and trifurcate tri- and tetramine backbone multidentate chelating agents based on the 8-hydroxyquinoline chelating unit. The chelating agents may optionally be substituted with a substate reactive moiety and antibody-metal ion conjugates may be produced for in vivo diagnostic and therapeutic methods.
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