1532-72-5Relevant academic research and scientific papers
Copper(II)-catalyzed electrophilic amination of quinoline N-oxides with O-benzoyl hydroxylamines
Li, Gang,Jia, Chunqi,Sun, Kai,Lv, Yunhe,Zhao, Feng,Zhou, Kexiao,Wu, Hankui
, p. 3207 - 3210 (2015)
Copper acetate-catalyzed C-H bond functionalization amination of quinoline N-oxides was achieved using O-benzoyl hydroxylamine as an electrophilic amination reagent, thereby affording the desired products in moderate to excellent yields. Electrophilic amination can also be performed in good yield on a gram scale. This journal is
The Mechanism of Thermal Eliminations. Part 21. Rate Data for Pyrolysis of 2-Ethoxyquinoline, 1-and 3-Ethoxyisoquinoline, and 1-Ethoxythiazole: Correlation of Reactivities with ?-Bond Order of the C=N Bond
Al-Awadi, Nouria,Taylor, Roger
, p. 1589 - 1592 (1986)
We have measured the rates of thermal elimination of ethylene from the title compounds between 587.3 and 722.9 K.The reactivities relative to 2-ethoxypyridine at 650 K are: 3-ethoxyisoquinoline (0.21), 2-ethoxyquinoline (3.13), 1-ethoxyisoquinoline (6.47), 2-ethoxythiazole (63.1).These reactivities parallel the ?-bond order of the C=N bond, though the exceptional reactivity of 2-ethoxythiazole is attributed to additional acceleration through +M electron release from sulphur to nitrogen.This emphasizes the greater relative importance of nucleophilic attack by the nitrogen upon the β-hydrogen atom as compared with the analogous mechanism for pyrolysis of esters.Because of semi-concentrated nature of the reaction, interruption of aromaticity is much less significant than in, for example, electrophilic aromatic substitution.Thus retention of the benzenoid character of the ring not involved in the elimination is not an important rate-determining feature, as shown by the lower reactivity of 3-ethoxyisoquinoline relative to 2- ethoxypyridine.The unimportance of the interruption of aromaticity of the benzenoid ring means that conjugative effects are better relayed to nitrogen in the β-naphthalene-like position (isoquinoline) than in the α-naphthalene-like position (quinoline).This is the reverse of the familiar pattern for reactions of naphthalene-like systems where full charges are involved, and may be an additional factor contributing to the higher reactivity of 1-ethoxyisoquinoline than of 2-ethoxyquinoline, as may also be the -I effect of the benzo substiutent.The conclusions are used to predict elimination rates for alkoxyheterocycles not yet studied.
Elimination of Carbon Monoxide by Electron Impact on Quinoline N-oxide, Carbostyril and 8-Hydroxyquinoline
Blumenthal, Thomas,Gillis, Richard G.,Porter, Quentin N.,Yeoh, Li Li
, p. 247 - 249 (1991)
Under electron impact, the molecular ions of quinoline N-oxide, carbostyril and 8-hydroxyquinoline lose carbon monoxide giving a fragment ion C8H7N (m/z 117), which was shown by collision-activated dissociation in each case to have the structure of the molecular ion of indole.Its formation from 8-hydroxyquinoline requires an unusual rearrangement.Isoquinoline N-oxide loses HCN rather than CO and gives a fragment which has the structure of the molecular ion of benzofuran.When the first three compounds were subjected to flash vacuum pyrolysis, quinoline N-oxide at 500-700 deg C gave carbostyril and indole was detected by gas chromatography/mass spectrometry.At 900 deg C carbostyril and 8-hydroxyquinoline both gave indole in small amounts, detected by gas chromatography/mass spectrometry.
Cu(II)-Catalyzed Construction of Heterobiaryls using 1-Diazonaphthoquinones: A General Strategy for the Synthesis of QUINOX and Related P,N Ligands
Biswas, Aniruddha,Pan, Subarna,Samanta, Rajarshi
, p. 1631 - 1636 (2022/03/14)
An efficient and straightforward method was developed for the synthesis of heterobiaryls using easily available N-oxides and diazonaphthoquinones under cheap Cu(II) catalysis. The developed method offered QUINOX and related congeners in a simple manner. A wide scope of important heterobiaryls was achieved with high site selectivity. The synthesized naphthols were transformed into the privileged related P,N ligands. Suitable resolution methods can directly afford the corresponding axially chiral heterobiaryls.
Method for preparing sulfone and N-oxygen compound by using green and efficient oxidation system
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Paragraph 0030-0032, (2021/01/29)
The invention discloses a method for preparing sulfone and N-oxygen compound by using a green and efficient oxidation system. The method comprises the following steps of: by using a tertiary amine compound or aromatic thioether or fatty thioether compound as a raw material, H2O2 as an oxidant, methanol as a reaction solvent and potassium carbonate as an alkali, introducing sulfuryl fluoride 5O2F2gas as an accelerator; performing stirring at room temperature under a sealed condition for oxidation reaction; and after finishing the reaction, filtering to remove solid potassium carbonate, dryingto remove water, filtering to obtain a crude product, and finally carrying out column chromatography separation to obtain a pure product. Tertiary amine is oxidized into an N-oxygen compound, and thethioether is oxidized into sulfone. According to the method, the sulfuryl fluoride (SO2F2) which is very cheap and easy to obtain is used as the reaction promoter, green and environment-friendly hydrogen peroxide (H2O2) is used as an oxidizing agent, and so that the yield of the reaction is generally high; after the reaction, byproducts are only water and inorganic salts (SO4 and F) whichare easy to remove and free of pollution, and the green and efficient oxidation system can be realized, and therefore, the method is suitable for large-scale industrial production.
SO2F2-mediated oxidation of primary and tertiary amines with 30% aqueous H2O2 solution
Liao, Xudong,Zhou, Yi,Ai, Chengmei,Ye, Cuijiao,Chen, Guanghui,Yan, Zhaohua,Lin, Sen
supporting information, (2021/11/01)
A highly efficient and selective oxidation of primary and tertiary amines employing SO2F2/H2O2/base system was described. Anilines were converted to the corresponding azoxybenzenes, while primary benzylamines were transformed into nitriles and secondary benzylamines were rearranged to amides. For tertiary amine substrates quinolines, isoquinolines and pyridines, their oxidation products were the corresponding N-oxides. The reaction conditions are very mild and just involve SO2F2, amines, 30% aqueous H2O2 solution, and inorganic base at room temperature. One unique advantage is that this oxidation system is just composed of inexpensive inorganic compounds without the use of any metal and organic compounds.
Waste-minimized synthesis of C2 functionalized quinolines exploiting iron-catalysed C-H activation
Ferlin, Francesco,Zangarelli, Agnese,Lilli, Simone,Santoro, Stefano,Vaccaro, Luigi
supporting information, p. 490 - 495 (2021/01/28)
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
Rhodium-Catalyzed Atroposelective Construction of Indoles via C?H Bond Activation
Sun, Lincong,Chen, Haohua,Liu, Bingxian,Chang, Junbiao,Kong, Lingheng,Wang, Fen,Lan, Yu,Li, Xingwei
supporting information, p. 8391 - 8395 (2021/03/03)
Reported herein is the rhodium(III)-catalyzed C?H activation of anilines bearing an N-isoquinolyl directing group for oxidative [3+2] annulation with four classes of internal alkynes, leading to atroposelective indole synthesis via dynamic kinetic annulation with C-N reductive elimination constituting the stereo-determining step. This reaction proceeds under mild conditions with high regio- and enantioselectivity and functional group compatibility.
Visible-Light-Induced Decarboxylative Acylation of Pyridine N-Oxides with α-Oxocarboxylic Acids Using Fluorescein Dimethylammonium as a Photocatalyst
Hou, Chuanfu,Sun, Shouneng,Liu, Ziqi,Zhang, Hui,Liu, Yue,An, Qi,Zhao, Jian,Ma, Junjie,Sun, Zhizhong,Chu, Wenyi
supporting information, p. 2806 - 2812 (2021/04/15)
Herein, the development of a visible-light-induced catalytic system to achieve the decarboxylative acylation of pyridine N-oxides with α-oxocarboxylic acids, at room temperature and using the organic dye fluorescein dimethylammonium as a new type of photocatalyst, is reported. A series of 2-arylacylpyridine N-oxides were selectively synthesized in moderate to good yields by controlling the polarity of the reaction solvent. The developed strategy was successfully applied in the synthesis of an important intermediate of the drug, acrivastine, on a gram scale. Notably, this is the first time that fluorescein dimethylammonium has been used to catalyze the Minisci-type C?H decarboxylative acylation reaction. The mechanism of decarboxylative acylation was studied by capturing adducts of acyl radicals and 1,1-diphenylethylene to confirm a radical mechanism. The disclosed catalytic system provides a green synthetic strategy for decarboxylative acylation without the use of additional oxidants or metal catalysts. (Figure presented.).
Design, synthesis, and biological evaluation of isoquinolin-1(2H)-one derivates as tankyrase-1/2 inhibitors
MO, JIANGWEN,PENG, YAN,WANG, YANYAN,WANG, ZHU,YAO, HAIPING
, p. 132 - 137 (2021/05/31)
To investigate structure-activity relationships of tankyrase (TNKS) inhibitors, twelve new derivatives of isoquinolin- 1(2H)-one were designed and synthesized, and biological assessments were conducted. Several potent TNKS inhibitors with single- or double-digit nanomolar IC50 values were identified using enzymatic assays. Compound 11c was the most potent compound of this series and inhibited TNKS1 and TNKS2 at an IC50 of 0.009 and 0.003 μM, respectively, and showed an IC50 of 0.029 μM in a DLD-1 SuperTopFlash assay. Molecular docking results showed that compound 11c occupied a unique subpocket and formed a hydrogen bond with Glu1138 of TNKS2, which was not consistent with the patterns of known TNKS inhibitors and thus warrants further research.
