6563-11-7Relevant academic research and scientific papers
Aza-boron-diquinomethene complexes bearing N-aryl chromophores: Synthesis, crystal structures, tunable photophysics, the protonation effect and their application as pH sensors
Zhu, Xiaolin,Huang, Hai,Liu, Rui,Jin, Xiaodong,Li, Yuhao,Wang, Danfeng,Wang, Qiang,Zhu, Hongjun
, p. 3774 - 3782 (2015)
A series of aza-boron-diquinomethene complexes (1a-1e) bearing different N-aryl chromophores were synthesized and characterized by multinuclear NMR spectroscopy, X-ray crystallography, optical absorption and emission spectroscopy, and elemental analysis. These robust thermal complexes possess tunable intense luminescence from blue to red with relatively high emission quantum yields. The introduction of different N-aryl chromophores into the aza-BODIQU core significantly tuned the emission colors. The relationship between their structures and properties was investigated systematically via spectroscopic methods and simulated by density functional theory (DFT) calculations. Additionally, the application of 1c as a pH sensor with a remarkable colour-changing property has been investigated. All these results indicate that these complexes exhibit robust thermal stability, tunable photophysical properties, relatively high photoluminescence quantum yields and protonation effect, making these complexes potential candidates for pH sensors, bioimaging probes and organic light-emitting materials.
2-Position-selective C[sbnd]H fluoromethylation of six-membered heteroaryl N-oxides with (fluoromethyl)triphenylphosphonium iodide
Hu, Chen-Chen,Hu, Wei-Qiang,Qing, Feng-Ling,Xu, Xiu-Hua
, (2020/12/14)
A mild and efficient method for the regioselective C[sbnd]H fluoromethylation of heteroaryl N-oxides with (fluoromethyl)triphenylphosphonium iodide is presented. With LiOt-Bu as the base and DMSO as the solvent, this reaction delivers a series of C2-fluor
From Pyridine- N-oxides to 2-Functionalized Pyridines through Pyridyl Phosphonium Salts: An Umpolung Strategy
Bugaenko, Dmitry I.,Yurovskaya, Marina A.,Karchava, Alexander V.
supporting information, p. 6099 - 6104 (2021/08/03)
The reactions of pyridine-N-oxides with Ph3P under the developed conditions provide an unprecedented route to (pyridine-2-yl)phosphonium salts. Upon activation with DABCO, these salts readily serve as functionalized 2-pyridyl nucleophile equivalents. This umpolung strategy allows for the selective C2 functionalization of the pyridine ring with electrophiles, avoiding the generation and use of unstable organometallic reagents. The protocol operates at ambient temperature and tolerates sensitive functional groups, enabling the synthesis of otherwise challenging compounds.
Efficient visible light mediated synthesis of quinolin-2(1H)-ones from quinolineN-oxides
Bhuyan, Samuzal,Chhetri, Karan,Hossain, Jagir,Jana, Saibal,Mandal, Susanta,Roy, Biswajit Gopal
supporting information, p. 5049 - 5055 (2021/07/29)
Quinolin-2(1H)-ones are one of the important classes of compounds due to their prevalence in natural products and in pharmacologically useful compounds. Here we present an unconventional and hitherto unknown photocatalytic approach to their synthesis from easily available quinoline-N-oxides. This reagent free highly atom economical photocatalytic method, with low catalyst loading, high yield and no undesirable by-product, provides an efficient greener alternative to all conventional synthesis reported to date. The robustness of the methodology has been successfully demonstrated with easy scaling up to the gram scale.
Reaction of Pyridine-N-Oxides with Tertiary sp2-N-Nucleophiles: An Efficient Synthesis of Precursors for N-(Pyrid-2-yl)-Substituted N-Heterocyclic Carbenes
Bugaenko, Dmitry I.,Karchava, Alexander V.,Yurovskaya, Marina A.
supporting information, p. 5777 - 5782 (2020/12/01)
N-(Pyrid-2-yl)-substituted azolium and pyridinium salts, precursors for hybrid NHC-containing ligands, were obtained with excellent regioselectivity, employing a deoxygenative CH-functionalization of pyridine-N-oxides with substituted imidazoles, thiazoles, and pyridine. Unlike the traditional SNAr-based methods, this approach provides high yields for substrates bearing substituents of different electronic nature. The utility of azolium and pyridinium salts thus prepared was also highlighted by the synthesis of pyridyl-substituted imidazolyl-2-thione, benzodiazepine as well as 2-aminopyridines.
COMPOSITIONS FOR THE TREATMENT OF BRAIN TUMORS
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Page/Page column 55, (2020/05/19)
The instant invention describes pharmaceutical compositions and dosing regimens comprising radiation therapy and seviteronel with or without dexamethasone, and methods of treating diseases, disorders or symptoms thereof.
Hypervalent Iodine(III)-Mediated Regioselective Cyanation of Quinoline N-Oxides with Trimethylsilyl Cyanide
Xu, Feng,Li, Yuqin,Huang, Xin,Fang, Xinjie,Li, Zhuofei,Jiang, Hongshuo,Qiao, Jingyi,Chu, Wenyi,Sun, Zhizhong
supporting information, p. 520 - 525 (2018/12/13)
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.).
Rh/O2-Catalyzed C8 Olefination of Quinoline N-Oxides with Activated and Unactivated Olefins
Sharma, Ritika,Kumar, Rakesh,Sharma, Upendra
, p. 2786 - 2797 (2019/02/26)
The rhodium/O2 system-catalyzed distal C(sp2)-H olefination of quinoline N-oxides is developed. Molecular oxygen has been explored as an economic and clean oxidant, an alternative to inorganic oxidants. A wide substrate scope with respect to quinoline N-oxides and olefins (activated acrylates and styrenes; unactivated aliphatic olefins) demonstrates the robustness of the developed catalytic method. Interestingly, 2-substituted quinoline N-oxides also afforded good yields of the corresponding C8-olefinated products. Kinetic isotope studies and deuterium-labeling experiments have been performed to understand the preliminary mechanistic pathway. The applicability of the developed method is demonstrated by utilizing natural product-derived substrates and by converting the C8-olefinated quinoline N-oxides into various other useful molecules.
Catalyst-Free Synthesis of 2-Anilinoquinolines and 3-Hydroxyquinolines via Three-Component Reaction of Quinoline N-Oxides, Aryldiazonium Salts, and Acetonitrile
Dhiman, Ankit Kumar,Chandra, Devesh,Kumar, Rakesh,Sharma, Upendra
, p. 6962 - 6969 (2019/06/14)
A rapid microwave-assisted, catalyst-free, three-component synthesis of various 2-anilinoquinolines from quinoline N-oxides and aryldiazonium salts in acetonitrile under microwave irradiation is reported. This reaction utilizes acetonitrile as a single nitrogen source and involves the formation of two new C-N bonds via the formal [3 + 2] cycloaddition reaction. In the case of 2-substituted quinolines, 3-hydroxyquinoline was observed as the main product via a 1,3 shift of the oxygen atom from N-oxide to the C3 position of quinolines.
2-Position-Selective Trifluoromethylthiolation of Six-Membered Heteroaromatic Compounds
Muta, Ryuhei,Torigoe, Takeru,Kuninobu, Yoichiro
supporting information, (2019/06/13)
The regioselective C-H trifluoromethylthiolation of six-membered heteroaromatic compounds via nucleophilic attack of a CF3S source on the electrophilically activated six-membered heteroaromatic ring was developed. The reaction proceeds in good yield with good functional group tolerance, even on a gram-scale. The key to the successful regioselective transformation is the presence of an additive (2,4-dinitrobenzenesulfonyl chloride). The regioselective trifluoromethylthiolation of quinidine derivative is also demonstrated. Trifluoromethylthiolation, followed by S-oxidation, affords the corresponding sulfones.
