- Hydrolysis of 8-quinolyl phosphate monoester: Kinetic and theoretical studies of the effect of lanthanide ions
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8-Quinolyl phosphate (8QP) in the presence of the trivalent lanthanide ions (Ln = La, Sm, Eu, Tb, and Er) forms a [Ln ? 8QP]+ complex where the lanthanide ion catalyzes hydrolysis of 8QP. In reactions with Tb 3+ or Er3+, t
- Souza, Bruno S.,Brandao, Tiago A. S.,Orth, Elisa S.,Roma, Ana C.,Longo, Ricardo L.,Bunton, Clifford A.,Nome, Faruk
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- (AEDPH3)·(8-OQH)·(H2O): A yellow supramolecular plaster with ammonia adsorption and ammonia-induced discoloration properties
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A novel supramolecular plaster, namely (AEDPH3)·(8-OQH) ·(H2O) (1), is synthesized and characterized. This plaster is an organic acid-base compound, which shows a three-dimensional (3D) sandwich-type supramolecular network. It is a yellow gelling material with excellent mechanical properties superior to that of gypsum plaster. Moreover, the plaster can adsorb ammonia (NH3) effectively, and exhibits an interesting ammonia-induced discoloration property.
- Tian, Di,Xiong, Juan,Liang, Xi-Chao,Deng, Jing,Yuan, Liang-Jie,Chen, Shuo-Ping
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- Photolysis of Zn(8-quinolinolate)2(H2O)2 in non-aqueous solution. Photoactivation of hydrolysis
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The octahedral complex Zn(8-quinolinolate)2(H2O) 2 in non-aqueous solvents (e.g. chloroform, cyclohexane) undergoes a photolysis: Zn(8-quinolinolate)2(H2O)2 → Zn(OH)2 + 2 8-quinolinole. It is suggested that this photohydrolysis is facilitated by hydrogen bonding. The irradiation (λ > 340 nm) is absorbed by the ligand chromophore. The IL excitation is associated with a charge shift from the coordinated phenolate to the nitrogen of the pyridine ring. As a consequence, the phenolate loses its coordinating ability. The subsequent deactivation is accompanied by the reversal of the charge shift. The regenerated phenolate may now undergo protonation from an adjacent water ligand in competition with the re-coordination to Zn2 +. This system represents a simple model for activation of water which is coordinated to zinc(II). In distinction to the enzymatic function the hydrolysis in our system is initiated by a light switch.
- Vogler, Arnd
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- Photodegradation of quinoline in water
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The photodegradation kinetics of quinoline have been studied at 313 nm and in sunlight in organic-free water, lake water, and water containing several different solutes. The half-life of sunlight photodegradation is slightly shorter in lake water than in organic-free water (4-8%, depending upon the season). In near-surface lake water at 40° N latitude in summer, quinoline was predicted to degrade readily in sunlight, with a half-life of about 14 calendar days. The calculated half-life in winter was about 123 calendar days. The photodegradation of quinoline was accelerated significantly by NaNO3 and dissolved organic matter, two effective producers of hydroxyl radicals in aquatic environments. The rate was also faster at pH 4.5 than at pH 7.0. Two photoproducts were identified in low yield, 2-hydroxyquinoline and 8-hydroxyquinoline; prolonged irradiation appeared to destroy the aromatic nucleus.
- Kochany, Jan,Maguire, R. James
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- A prochelator with a modular masking group featuring hydrogen peroxide activation with concurrent fluorescent reporting
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Metal chelators masked with protecting groups for targeted release have the potential to conditionally modulate cellular metals. We report a new route to prepare cis-cinnamate protecting groups that enabled development of a prochelator with chemical stimulus response, fluorescent reporting and active compound release in a single structure. the Partner Organisations 2014.
- Franks, Andrew T.,Franz, Katherine J.
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- Effect of Poly(diallyldimethylammonium Chloride) and of Poly(ethyleneimine) on the Esterolysis of 8-Acetoxyquinoline
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The esterolysis of 8-acetoquinoline (8-AQ) in aqueous solution in the presence of an excess of poly(diallyldimethylammonium chloride) (PDDA) or poly(ethylenimine) (PEI) was investigated at 30 deg C.In the presence of PDDA hydrolysis takes place and the polyion does not affect the rate of the reaction.In the presence of PEI the ester undergoes aminolysis and saturation kinetics are observed.The pH dependence of kobs, the apparent first-order rate constant of esterolysis, can be explained on the basis of the pH dependence of pKapp and the degree of ionization of PEI.A Broensted relationship has already been found for the aminolysis of 8-AQ with primary and secondary amines of low molecular weight.By extending the relationship to the reaction between the polymeric amino groups in PEI and 8-AQ, we can quantitatively predict the pH dependence of kobs under saturation conditions, provided that the proper values of pKapp of the amino groups are considered.
- Arcelli, Antonio,Concilio, Carlo
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- Synthesis of quinolines by iron-catalyzed reaction of anilines with propane-1,3-diol
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Quinoline and its derivatives were synthesized by cyclocondensation of anilines with propane-1,3-diol in 57-96% yield in the presence of iron-containing catalysts in carbon tetrachloride.
- Khusnutdinov,Bayguzina,Aminov
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- Solid-state structural transformations of two AgI supramolecular polymorphs to another polymer upon absorption of HNO3 vapors
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Solid-state structural transformation of two polymorphic forms of [Ag(8-HqH)(8-Hq)]n (1α and 1β, where 8-HqH = 8-hydroxyquinoline and 8-Hq- = 8-hydroxyquinolate) to {[Ag(8-HqH)2]NO3}n (2) has been observed upon solid-gas reaction of compounds 1α and 1β with HNO3 vapors. Solid-gas reaction of compound 2 with hydrated vapors of NH3 results in the formation of only the 1β polymorph, while solid-solid reaction of compound 2 with KOH results in the formation of a 1α and 1β mixture with chiral and achiral space groups of P212 121 and Pbcn, respectively.
- Akhbari, Kamran,Morsali, Ali
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- A prochelator activated by hydrogen peroxide prevents metal-induced amyloid β aggregation
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(Chemical Equation Presented) The masked marvel: Elevated production of H2O2 by deviant species of Cu-Aβ (Cu-amyloid beta) might trigger neurodegeneration in Alzheimer's disease. A new boronic ester-masked prochelator called QBP is activated under conditions that mimic early Alzheimer's pathology in which copper, Aβ, and reductants exacerbate reactive oxygen species formation. Once activated to its unmasked form, the released chelator diminishes copper's pro-oxidant reactivity and inhibits Aβ aggregation.
- Dickens, Marina G.,Franz, Katherine J.
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- Properties and infrared spectra in the potassium bromide region of 8-quinolinol and its metal chelates
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The infrared absorption spectra in the 11-25 μ region of 8-quinolinol and the 8-quinolinol chelates of the alkaline earth ions, manganese(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), lead(II), aluminum(III), iron(III), thorium(IV), and uranium(Vl) have been recorded and band assignments have been made. A consideration of the spectral shifts has been used to study the structures of the divalent metal chelates in the solid phase. The spectral data indicate that the divalent ions which have available d-orbitals bond differently with 8-quinolinol from those without available d-orbitals. The solvate oxine in the thorium(IV) and uranium(VI) chelates is not distinguishable from the ligand oxines on the basis of the infrared data. Structures for the a and β forms of copper oxinate are proposed.
- Tackett, James E.,Sawyer, Donald T.
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- Dissociation of μ-Oxo-bis and μ-Oxo-bis in Chlorobenzene
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Dissociation of dimeric vanadium(V) complexes with 8-quinolinol(Hox) and 4-isopropyltropolone(Hipt), V2O3(ox)4 and V2O3(ipt)4, in organic solvents was studied spectrophotometrically.The equilibrium is found to be V2O3L4 + H2O 2VO2L + 2HL with the foll
- Yuchi, Akio,Muranaka, Hiroshi,Yamada, Shinkichi,Tanaka, Motoharu
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- Method for realizing oxidative dehydrogenation of nitrogen-containing heterocyclic ring by using biomass-based carbon material
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The invention provides a method for realizing oxidative dehydrogenation of a nitrogen-containing heterocyclic ring by using a biomass-based carbon material, and belongs to the field of organic synthesis. According to the method, the raw materials of the biomass-based carbon material comprise wheat, sorghum, rice, corn straw, wheat straw, peanut shells, sesame shells, bean shells and the like, and are crushed and then ground into powder, the powder is fully mixed with an inorganic alkali, and calcination is performed in an inert gas atmosphere to prepare the biomass-based carbon material; and by using air as an oxygen source, at a temperature of 50-120 DEG C, oxidative dehydrogenation of nitrogen-containing heterocyclic compounds to synthesize quinoline compounds, isoquinoline compounds, acridine compounds, quinazoline compounds, indole compounds, imine compounds, and even quinoline compounds with pharmaceutical activity can be achieved. According to the present invention, easily available wheat flour is adopted as a raw material to prepare a non-metal catalyst, the alkali is not added during the reaction process, and a remarkable industrial application prospect is achieved.
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Paragraph 0010-0011; 0030-0031
(2021/06/26)
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- Electrochemical-induced hydroxylation of aryl halides in the presence of Et3N in water
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A thorough study of mild and environmentally friendly electrochemical-induced hydroxylation of aryl halides without a catalyst is presented. The best protocol consists of hydroxylation of different aryl iodides and aryl bromides by water solution in the presence of Et3N under air, affording the target phenols in good isolated yields. Moreover, aryl chlorides were successfully employed as substrates. This methodology also provides a direct pathway for the formation of deoxyphomalone, which displayed a significant anti-proliferation effect.
- Ke, Fang,Lin, Chen,Lin, Mei,Long, Hua,Wu, Mei,Yang, Li,Zhuang, Qinglong
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supporting information
p. 6417 - 6421
(2021/08/03)
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- Photocatalytic synthesis of phenols mediated by visible light using KI as catalyst
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A transition-metal-free hydroxylation of iodoarenes to afford substituted phenols is described. The reaction is promoted by KI under white LED light irradiation and uses atmospheric oxygen as oxidant. By the use of triethylamine as base and solvent, the corresponding phenols are obtained in moderate to good yields. Mechanistic studies suggest that KI and catalysis synergistically promote the cleavage of C-I bond to form free aryl radicals.
- Huiqin, Wei,Wu, Mei
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supporting information
(2021/11/30)
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- Geometric and electronic effects on the performance of a bifunctional Ru2P catalyst in the hydrogenation and acceptorless dehydrogenation of N-heteroarenes
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The development of bifunctional catalysts for the efficient hydrogenation and acceptorless dehydrogenation of N-heterocycles is a challenge. In this study, Ru2P/AC effectively promoted reversible transformations between unsaturated and saturated N-heterocycles affording yields of 98% and 99%, respectively. Moreover, a remarkable enhancement in the reusability of Ru2P/AC was observed compared with other Ru-based catalysts. According to density functional theory calculations, the superior performance of Ru2P/AC was ascribed to specific synergistic factors, namely geometric and electronic effects induced by P. P greatly reduced the large Ru-Ru ensembles and finely modified the electronic structures, leading to a low reaction barrier and high desorption ability of the catalyst, further boosting the hydrogenation and acceptorless dehydrogenation processes.
- Shao, Fangjun,Yao, Zihao,Gao, Yijing,Zhou, Qiang,Bao, Zhikang,Zhuang, Guilin,Zhong, Xing,Wu, Chuan,Wei, Zhongzhe,Wang, Jianguo
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p. 1185 - 1194
(2021/02/16)
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- Method for synthesizing phenol or derivative thereof in aqueous phase by photocatalytic one-pot method
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The invention discloses a method for synthesizing phenol or a derivative thereof in an aqueous phase by a photocatalytic one-pot method. The method comprises the following steps: by taking a compoundaryl halide shown in formula (I) as a raw material and water as a solvent, adding a catalyst and an auxiliary agent, and carrying out reacting under the conditions of alkali and visible light to obtain the phenol or the derivative (II) thereof. Compared with the prior art, the method is applicable to a large number of functional groups, high in yield, few in byproducts, simple and safe to operate,low in cost and environmentally friendly, wherein R is selected from substituted or non-substituted phenyl, pyridyl, quinolyl or pyrimidinyl; X is selected from halogen; the substituted phenyl is substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, halogen, cyano, aldehyde group, nitro, amino, acetyl or carboxyl; and the substituted pyridyl, quinolyl or pyrimidinyl is pyridyl, quinolyl or pyrimidinyl substituted by C1-C4 alkyl.
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Paragraph 0032-0033; 0083-0084; 0085-0106
(2020/12/08)
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- A Mild Method for Electrochemical Reduction of Heterocyclic N-Oxides
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Deoxygenation of heteroaromatic N-oxides is commonly accomplished using chemical or enzymatic methods. In this work, we report on an expedient protocol for electrochemical reduction of pyridine N-oxide derivatives under mild conditions. A diverse range of mono- and bis N-oxides were converted into the corresponding nitrogen bases in good yields. Importantly, the method is highly selective towards N-oxides and tolerates challenging halo and nitro substituents in the heteroaromatic ring.
- Fukazawa, Yasuaki,Rubtsov, Aleksandr E.,Malkov, Andrei V.
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supporting information
p. 3317 - 3319
(2020/05/25)
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- Visible-Light-Promoted Efficient Aerobic Dehydrogenation of N-Heterocycles by a Tiny Organic Semiconductor Under Ambient Conditions
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An efficient reusable catalytic system has been developed based on perylene diimide (PDI) organic semiconductor for the aerobic dehydrogenation of N-heterocycles with visible light. This practical catalytic system without any additives proceeds under ambient conditions. The minute aggregates of PDI molecules on the surface of SiO2 nanospheres form tiny organic semiconductors, resulting in high-efficiency photo-oxidative activity. Notably, the robustness of this method is demonstrated by the synthesis of a wide range of N-heteroarenes, gram-scale experiments as well as reusability tests.
- Su, Chenliang,Yu, Kunyi,Zhang, Hanjie,Zhu, Yongfa
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supporting information
p. 1956 - 1960
(2020/04/10)
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- Production method of 8-hydroxyquinoline
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The invention is applicable to the technical field of chemical industry production, and provides a production method of 8-hydroxyquinoline. The method comprises the following steps: stirring and mixing o-aminophenol, o-nitrophenol and an acid solution to obtain a mixture; dropwise adding glycerol into the mixture, and carrying out a cyclization reaction to obtain a reaction solution; neutralizingthe reaction solution with an alkali liquid until the pH value is 7-8, and separating to obtain an organic phase; and carrying out water washing and layering on the organic phase, and then sequentially carrying out reduced pressure distillation, condensation and crushing treatment to obtain the 8-hydroxyquinoline. According to the method, o-aminophenol and o-nitrophenol are firstly added, concentrated sulfuric acid is dropwise added, and then glycerol is added, so that the product can be directly synthesized by a one-pot method, the production method effectively reduces side reactions, the yield and the quality of the 8-hydroxyquinoline product are further improved, the product conversion rate can reach 96%, and the product yield can reach 91%.
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Paragraph 0020-0039; 0041-0042
(2020/11/09)
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- Superhydrophobic nickel/carbon core-shell nanocomposites for the hydrogen transfer reactions of nitrobenzene and N-heterocycles
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In this work, catalytic hydrogen transfer as an effective, green, convenient and economical strategy is for the first time used to synthesize anilines and N-heterocyclic aromatic compounds from nitrobenzene and N-heterocycles in one step. Nevertheless, how to effectively reduce the possible effects of water on the catalyst by removal of the by-product water, and to further introduce water as the solvent based on green chemistry are still challenges. Since the structures and properties of carbon nanocomposites are easily modified by controllable construction, a one step pyrolysis process is used for controllable construction of micro/nano hierarchical carbon nanocomposites with core-shell structures and magnetic separation performance. Using various characterization methods and model reactions the relationship between the structure of Ni?NCFs (nickel-nitrogen-doped carbon frameworks) and catalytic performance was investigated, and the results show that there is a positive correlation between the catalytic performance and hydrophobicity of catalysts. Besides, the possible catalytically active sites, which are formed by the interaction of pyridinic N and graphitic N in the structure of nitrogen-doped graphene with the surfaces of Ni nanoparticles, should be pivotal to achieving the relatively high catalytic performance of materials. Due to its unique structure, the obtained Ni?NCF-700 catalyst with superhydrophobicity shows extraordinary performances toward the hydrogen transfer reaction of nitrobenzene and N-heterocycles in the aqueous state; meanwhile, it was also found that Ni?NCF-700 still retained its excellent catalytic activity and structural integrity after three cycles. Compared with traditional catalytic systems, our catalytic systems offer a highly effective, green and economical alternative for nitrobenzene and N-heterocycle transformation, and may open up a new avenue for simple construction of structure and activity defined carbon nanocomposite heterogeneous catalysts with superhydrophobicity.
- Duan, Zhiying,Liu, Fangfang,Pang, Shaofeng,Su, Qiong,Wang, Yanbin,Xie, Xin,Zhang, Ping,Zhang, Yujing,Zhou, Feng
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p. 1996 - 2010
(2020/04/07)
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- Superacid-promoted synthesis of quinoline derivatives
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A series of vinylogous imines have been prepared from anilines and cinnamaldehydes. These substrates react in superacidic media to provide quinolines and related compounds. A mechanism for the conversion is proposed which involves the cyclization of dicationic superelectrophilic intermediates. Aromatization of the quinoline ring is thought to occur by superacid-promoted elimination of benzene.
- Klumpp, Douglas A.,Stentzel, Michael R.,Vuong, Hein
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supporting information
(2020/01/24)
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- A Reusable Cobalt Catalyst for Reversible Acceptorless Dehydrogenation and Hydrogenation of N-Heterocycles
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The development of robust catalytic systems based on base-metals for reversible acceptorless dehydrogenation (ADH) and hydrogenation of feedstock chemicals is very important in the context of ‘hydrogen storage’. Herein, we report a highly efficient reusable cobalt-based heterogeneous catalyst for reversible dehydrogenation and hydrogenation of N-heterocycles. Both the ADH and the hydrogenation processes operate under mild, benign conditions.
- Jaiswal, Garima,Subaramanian, Murugan,Sahoo, Manoj K.,Balaraman, Ekambaram
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p. 2449 - 2457
(2019/05/10)
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- Corrigendum: Organo-Photoredox Catalyzed Oxidative Dehydrogenation of N-Heterocycles (Chemistry - A European Journal, (2017), 23, 57, (14167-14172), 10.1002/chem.201703642)
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The authors have been alerted to an error that was unfortunately missed at the time of publication. Table was duplicated with Table 4. The correct version of Table 2 is shown below. The authors apologise for any inconvenience caused. Organo-photoredox catalyzed oxidative dehydrogenation of tetrahydroquinolines (THQ).[a,b] (Table presented.) [a] Reaction conditions: 1 (0.5 mmol), rose bengal (1.0 mol %), N,N-dimethylacetamide (2.0 mL), open air atmosphere under visible-light irradiation at room temperature for 24 h. [b] Isolated yields. [c] 0.1 mol % of photoredox catalyst for 28 h.
- Sahoo, Manoj K.,Jaiswal, Garima,Rana, Jagannath,Balaraman, Ekambaram
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p. 7038 - 7038
(2019/05/17)
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- Preparation method of 8-hydroxyquinoline
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The invention relates to a preparation method of 8-hydroxyquinoline. The preparation method comprises the following steps: A), uniformly mixing quinoline and a sulfonating agent, performing a sulfonation reaction, and hydrolyzing to obtain a reaction solid and reaction liquid; B), under the action of a catalyst, heating the reaction solid obtained in the step A), water and inorganic strong alkali,and reacting to obtain the 8-hydroxyquinoline, wherein the catalyst is one or more of methanol, ethanol and isopropanol. By the preparation method, through addition of the catalyst during the reaction, the reaction temperature in an alkali-melting step in the production process of the 8-hydroxyquinoline is reduced, so that a requirement on equipment is reduced and the danger coefficient in actualproduction is also reduced, and thus a reaction condition is mild, operation is easy, and the purity and the yield are relatively high; meanwhile, through the addition of the catalyst, the using amount of the inorganic strong alkali is reduced, so that the production cost is reduced; in addition, the reaction liquid produced in the sulfonation reaction is recycled in a subsequent acidification process, so that discharge of waste liquid is reduced and clean production is achieved.
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Paragraph 0042; 0044; 0045; 0047; 0048; 0050
(2018/03/26)
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- Synthesis of substituted phenols via hydroxylation of arenes using hydrogen peroxide in the presence of hexaphenyloxodiphosphonium triflate
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A mild and efficient protocol for the synthesis of phenols from arenes has been developed using aqueous hydrogen peroxide as an oxidizing agent and hexaphenyloxodiphosphonium triflate as a promoter. The reactions were carried out with the simple procedure in EtOH-H2O at room temperature in short reaction times.
- Khodaei, Mohammad Mehdi,Alizadeh, Abdolhamid,Hezarkhani, Hadis Afshar
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p. 878 - 882
(2018/11/06)
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- Method of synthesizing 8-hydroxyquinoline
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The invention discloses a method of synthesizing 8-hydroxyquinoline. Ortho-aminophenol and acrolein are used as raw materials, and hydroquinone is used as a polymerization inhibitor; an addition reaction and a cyclization reaction are carried out under the acidic condition to obtain an intermediate, and a cobalt oxime chelate photocatalyst and an eosin Y photosensitizer are directly added withoutthe need of separation of the intermediate; and an acetonitrile solvent and deionized water are added, under continuous irradiation of visible light, the 8-hydroxyquinoline is obtained through a photocatalytic dehydrogenation oxidation reaction. The reaction process is easy to control, by-products are few, post-treatment is simple, and the generated target product is good in selectivity, high in yield and stable.
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Paragraph 0038-0044
(2019/01/14)
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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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- C70 Fullerene-Catalyzed Metal-Free Photocatalytic ipso-Hydroxylation of Aryl Boronic Acids: Synthesis of Phenols
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A metal-free C70 fullerene-catalyzed method has been developed for the ipso-hydroxylation of aryl and heteroaryl boronic acids to corresponding phenols under photocatalytic conditions. The reaction proceeds under oxygen atmosphere and the mechanistic study revealed that C70 plays a critical role in the generation of reactive oxygen species in the presence of blue light. Reactions in the presence of 18O-labelled water and oxygen confirmed the generation of reactive oxygen species from oxygen molecule. Amine used as a reductant could be recovered in the form of imine. The current method is also applicable to the synthesis of aryl ethers in one-pot two-step process. (Figure presented.).
- Kumar, Inder,Sharma, Ritika,Kumar, Rakesh,Kumar, Rakesh,Sharma, Upendra
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supporting information
p. 2013 - 2019
(2018/04/02)
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- A rapid, solvent-free deprotection of methoxymethyl (MOM) ethers by pTSA; An eco-friendly approach
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Background: Ease of preparation and alkaline stability of methoxymethyl (MOM) makes it an important hydroxyl protecting group. A number of methods are available for the deprotection of MOM. Though the methods are good in general, they use solvents, require prolonged reaction time and tedious work up. A solvent free, solid phase, fast deprotection of MOM has been developed and is the major theme of this paper. Methods: A mixture of MOM protected compounds and pTSA is triturated in a mortar (5 min) and left at room temperature for 30 min. On addition of water (4°C), pTSA, methanol and formaldehyde dissolved leaving the products as precipitates. Results: A series of different MOM ethers were deprotected by this method in good to excellent yield (85-98%). The compatibility of MOM in the presence of other protections such as methoxyl, benzyl, ester, amide, allyl and lactone was also established. Acetate protection is not stable under these conditions. Conclusion: An efficient, selective and high yielding deprotection MOM groups by pTSA under solvent free condition is described. The process is environment friendly since no solvent was used in the deprotection process. The reaction conditions are mild and should be useful for the deprotection of MOM derivatives of complex and labile molecules.
- Pandurangan, Nanjan
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p. 231 - 235
(2017/07/15)
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- Assembly of Diversely Substituted Quinolines via Aerobic Oxidative Aromatization from Simple Alcohols and Anilines
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An aerobic oxidative aromatization of simple aliphatic alcohols and anilines under the Pd(OAc)2/2,4,6-Collidine/Br?nsted acid catalytic system has been established, providing a direct approach for the preparation of diverse substituted quinoline derivatives in high yields with wide functional group tolerance. Practically, the protocol can be easily scaled up to gram-scale and was utilized in the concise formal synthesis of a promising herbicide candidate.
- Li, Jixing,Zhang, Jinlong,Yang, Huameng,Jiang, Gaoxi
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supporting information
p. 3284 - 3290
(2017/03/23)
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- Organo-Photoredox Catalyzed Oxidative Dehydrogenation of N-Heterocycles
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We report here for the first time the catalytic oxidative dehydrogenation of N-heterocycles by a visible-light organo-photoredox catalyst with low catalyst loading (0.1–1 mol %). The reaction proceeds efficiently under base- and additive-free conditions with ambient air at room temperature. The utility of this benign approach is demonstrated by the synthesis of various pharmaceutically relevant N-heteroarenes such as quinoline, quinoxaline, quinazoline, acridine, and indole.
- Sahoo, Manoj K.,Jaiswal, Garima,Rana, Jagannath,Balaraman, Ekambaram
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supporting information
p. 14167 - 14172
(2017/10/16)
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- Dehydrogenation of Nitrogen Heterocycles Using Graphene Oxide as a Versatile Metal-Free Catalyst under Air
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Graphene oxide (GO) has been developed as an inexpensive, environmental friendly, metal-free carbocatalyst for the dehydrogenation of nitrogen heterocycles. Valuable compounds, such as quinoline, 3,4-dihydroisoquinoline, quinazoline, and indole derivatives, have been successfully used as substrates. The investigation of various oxygen-containing molecules with different conjugated systems indicated that both the oxygen-containing groups and large π-conjugated system in GO sheets are essential for this reaction. (Figure presented.).
- Zhang, Jingyu,Chen, Shiya,Chen, Fangfang,Xu, Wensheng,Deng, Guo-Jun,Gong, Hang
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supporting information
p. 2358 - 2363
(2017/07/22)
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- Palladium Nanoparticles Stabilized by Metal–Carbon Covalent Bonds as an Expeditious Catalyst for the Oxidative Dehydrogenation of Nitrogen Heterocycles
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The first method for the dehydrogenation of nitrogen heterocycles catalyzed by a palladium nanocatalyst was developed. Carbon–metal covalent-bond-stabilized nanoparticles were found to be efficient for the dehydrogenation process in the presence of tert-butyl hydroperoxide. A variety of N-heterocycles were transformed into functionalized quinolines in medium to excellent yields in water as the solvent under mild conditions by a simple operation.
- Sun, Xiao-Tao,Zhu, Jie,Xia, Yun-Tao,Wu, Lei
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p. 2463 - 2466
(2017/07/12)
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- KHF2: A mild and selective desilylating agent for phenol tert-butyldimethylsilyl (TBDMS) ethers
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TBDMS (t-BuMe2Si, tert-butyldimethylsilyl) ethers of a variety of phenols have been deprotected with KHF2 in MeOH, at room temperature. Carboxylic ester and labile phenolic acetate were unaffected under these conditions. In competition reactions between TBDMS ethers of a phenol and two primary benzylic alcohols, the phenolic ether underwent cleavage whereas the alcohol ethers remained intact. From a substrate containing both a phenolic hydroxyl group and a secondary, doubly benzylic hydroxyl group protected as TBDMS ethers, the phenol was rapidly and selectively released. Cleavage of TBDMS, TBDPS, and TIPS ethers of a phenol was also compared. TBDMS and TBDPS ethers underwent cleavage at room temperature within 30 minutes, whereas removal of the TIPS ether required 2.5 hours. Ease of cleavage appears to be TBDMS ≈ TBDPS > TIPS. At 60°C, TBDMS ethers of primary benzylic, allylic, and unactivated alcohols can be efficiently desilylated over a prolonged period (13-17 h). Thus, KHF2 proves to be a mild and effective reagent for the selective desilylation of phenol TBDMS ethers at room temperature.
- Lakshman, Mahesh K.,Tine, Fatou A.,Khandaker, Tashrique A.,Basava, Vikram,Agyemang, Nana B.,Benavidez, Michael S.A.,Ga?i, Marikone,Guerrera, Lisa,Zajc, Barbara
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supporting information
p. 381 - 385
(2017/02/10)
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- A 8-hydroxy quinoline synthesis method (by machine translation)
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The present invention provides a kind of 8-hydroxy quinoline synthesis method, the steps are as follows : (1) added to the fuming sulfuric acid in four-mouth bottle, actuated stirring, 12 °C the quinoline is put into the constant pressure dropping funnel, and then the quinoline dropping slowly added in four-mouth bottle, completion of the postheating to 90-110°C, thermal insulation sulfonated 3 hours ; (2) the solution in the tube is moved to the radiation, nitrogen 30 minutes and then closed, the irradiation in a cobalt source 2 hours, the solution is taken out after, adding ice water for dilution, frozen 1 day, to crystallize, filtering, drying to obtain 8-sulfonic acid quinolines ; (3) in the four bottle by the addition of a base, heating to 260-320 °C enable its fusing, adding stirring 8-sulfonic acid quinolines, thermal insulation reaction 3 hours, the temperature after the completion of the 90 °C, adding distilled water to make its full dissolved, cooling to room temperature, neutralized to the solution for PH 7, after filtration of the precipitated crystals of distillation, to obtain white crystalline solid 8-hydroxy quinoline. The operation of the invention is simple, low cost, high yield. (by machine translation)
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Paragraph 0020; 0021; 0022; 0023; 0024
(2016/10/31)
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- A 8-hydroxy quinoline method of preparing copper
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The invention discloses a preparation method of copper 8-hydroxyquinoline, belonging to the technical field of organic synthesis. The preparation method comprises the following steps: (1) heating quinoline and fuming sulfuric acid to react, hydrolyzing to obtain quinolyl-8-sulfonic acid, and heating the quinolyl-8-sulfonic acid and solid sodium hydroxide to react to obtain 8-hydroxyquinoline; and (2) completely dissolve sodium hydroxide and the 8-hydroxyquinoline prepared in the step (1) in water, and adding anhydrous cupric sulfate to react to obtain the copper 8-hydroxyquinoline. The method is high in yield; and the prepared copper 8-hydroxyquinoline has the advantages of high purity, stable product quality and stable color, and is suitable for the high-end produce market.
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Paragraph 0025; 0028
(2017/04/13)
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- 8-hydroxyquinoline and preparation method thereof
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The invention discloses 8-hydroxyquinoline and a preparation method thereof. The preparation method comprises the following steps: (1) preparing a reaction reagent A, namely, mixing ortho-aminophenol and o-nitrophenol; (2) preparing a reaction reagent B, namely, mixing formic acid and acrolein, and adding a zeolite molecular sieve into a mixed liquid of the formic acid and the acrolein; (3) heating the reaction reagent A to 95-100 DEG C, adding the reaction reagent B, enabling the component to react under a condition of constant-temperature stirring, filtering, and cooling the filtrate to the room temperature; and (4) neutralizing the filtrate obtained in the step (3) by using a 40% sodium hydroxide solution, filtering again, and performing reduced pressure distillation, thereby obtaining a final expected product, that is, 8-hydroxyquinoline. Compared with the prior art, the preparation method has the advantages of rapid reaction, gentle condition and high yield and is particularly applicable to industrial production.
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Paragraph 0025; 0026; 0027; 0028; 0029; 0030
(2016/12/16)
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- Formation of 2,2-dimethylchroman-4-ones during the photoinduced rearrangement of some aryl 3-methyl-2-butenoate esters. A mechanistic insight
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Several aryl 3-methyl-2-butenoate esters upon irradiation lead to the formation of [1,3]-migrated photoproducts, phenol and, surprisingly 2,2-dimethylchroman-4-one derivatives. The starting photochemical reaction takes place from the singlet excited state of the ester and as a total mechanism two consecutive reaction pathways are proposed. The former involves the photo-Fries rearrangement of the esters in all the solvents studied and, depending on the proticity of the solvent, the latter involves an ESIPT process followed by thermal 6π-electrocyclic reaction and/or thermal (intramolecular oxa-Michael addition) cyclization of the ortho regioisomers photoformed. This second pathway is responsible of the formation of the 2,2-dimethylchroman-4-one derivatives.
- Iguchi, Daniela,Erra-Balsells, Rosa,Bonesi, Sergio M.
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p. 1903 - 1910
(2016/04/05)
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- Synthesis method of 8-hydroxyquinoline
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The invention discloses a synthesis method of 8-hydroxyquinoline. On the basis of Skraup reaction, reaction conditions are optimized, and 8-hydroxyquinoline is obtained through cyclization reaction of glycerinum and ortho-aminophenol; by adding anhydrous cupric sulfate and calcium oxide, water in a system can be absorbed, and concentrated sulfuric acid efficiency can be improved; meanwhile, dehydration cyclization of an addition product of aniline and acrolein can be accelerated, reaction speed is increased, reaction yield is ensured, and high economic benefits are achieved.
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Paragraph 0037; 0038; 0039; 0040; 0041; 0042; 0059; 0060
(2017/01/02)
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- Study of solvatochromic behavior and antimicrobial activities of some newly synthesized bis-azo-dapsone congeners
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In the present study, a series of new bisazo dyes derived from dapsone have been synthesized in one step, using diazotized coupling reaction and evaluated for their in-vitro antimicrobial activity. Ampicillin and fluconazole have been taken as reference antibiotics (RA). The structure of synthesized compounds are confirmed by different spectral techniques viz. elemental analysis, 1H NMR, UV-Vis, FT-IR and mass spectrometry. The solvatochromic behavior of the synthesized compounds are also studied by UV-Vis spectrometry. The compound 4b has been observed with significant antibacterial activity against Shigella flexneri, Escherichia coli, Vibrio cholera and Streptococcus mitis in comparison to standard drug whereas all the compounds except 4f show significant antifungal activity against Aspergillus niger. The results have been statistically interpreted by one way analysis-of variance (ANOVA) followed by Dunnett's Post Hoc test. Exploitation of dapsone molecule by the attachment of different nucleophiles may be responsible for the significant increase of antimicrobial activity. However, the 8-hydroxy quinoline linked bisazo dapsone showed highest significant antimicrobial activity than the other newly synthesized bisazo dapsone analogues in comparison to RA.
- Sahoo, Jyotirmaya,Kumar, Paidesetty Sudhir
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p. 724 - 733
(2017/01/18)
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- 8-hydroxyquinoline and synthetic method thereof
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The invention discloses 8-hydroxyquinoline and a synthetic method thereof.Ortho-aminophenol, anhydrous glycerol and o-nitrophenol are used as raw materials in the synthetic method.The synthetic method includes the steps of (1), dissolving nickel sesquioxide in concentrated sulfuric acid, stirring at room temperature, dropwise adding glacial acetic acid into a mixture, and stirring continuously for 1 hour after dropwise adding is completed so as to obtain a catalyst; (2), adding the ortho-aminophenol, the anhydrous glycerol and the o-nitrophenol into a reactor with stirring intensely, dropping the catalyst obtained in the step 1, stirring continuously for 5 hours by maintaining the temperature at 70-90 DEG C, regulating a pH value to be 7-8 after reaction is completed, distilling to obtain crude 8-hydroxyquinoline and subjecting the crude 8-hydroxyquinoline to ethanol recrystallization so as to obtain the 8-hydroxyquinoline.The synthetic method has the advantages of higher yield of the 8-hydroxyquinoline, reduction of by-products, high purity of the 8-hydroxyquinoline, mild reaction temperature, safe preparation process and easiness for large-scale industrial production.
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Paragraph 0027; 0028; 0029; 0030
(2016/12/16)
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- Quinoline synthesis by improved Skraup-Doebner-Von Miller reactions utilizing acrolein diethyl acetal
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A robust synthetic method has been developed as an improvement to the venerable Skraup-Doebner-Von Miller reaction providing access to various quinoline products. The straightforward procedure utilizes acrolein diethyl acetal as a three-carbon annulation partner with aniline substrates in a monophasic, organic solvent-free reaction medium. Differentially substituted aniline precursors were found to be compatible with the reaction conditions and the corresponding quinoline products are isolated in moderate to good yields.
- Ramann, Ginelle A.,Cowen, Bryan J.
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supporting information
p. 6436 - 6439
(2015/11/16)
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- 2,4-dinitrophenyl ether-containing chemodosimeters for the selective and sensitive in vitro and in vivo detection of hydrogen sulfide
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Four probes (i.e. D1-D4) for the selective and sensitive fluorogenic detection of HS- have been prepared and characterised. HEPES (10 mM, pH 7.4)-DMSO 99:1 v/v solutions of D1-D4 are essentially non-fluorescent. Changes in the emission using D1-D4 in the presence of anions (F-, Cl-, Br-, I-,N-3, CN-, SCN-, AcO-,CO2-3 ,PO2-4,SO2-4, HS- and OH-), biothiols (GSH, Cys, Hcy, Me-Cys and lipoic acid), reducing agents (SO2-3 and S2O2-3) and oxidants (H2O2) demonstrated that only HS- is able to induce the appearance of intense emission bands in the 400-520 nm range in the four probes. The selectivity observed was ascribed to a unique hydrogen sulfide-induced hydrolysis of the 2,4-dinitrophenyl ether moiety that yielded the corresponding free highly fluorescent alcohols. The potential detection of intracellular HS- was also studied.
- El Sayed, Sameh,De La Torre, Cristina,Santos-Figueroa, Luis E.,Martinez-Manez, Ramon,Sancenon, Felix,Orzaez, Mar,Costero, Ana M.,Parra, Margarita,Gil, Salvador
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p. 244 - 254
(2015/10/20)
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- Synthesis and Characterization of Iron-Nitrogen-Doped Graphene/Core-Shell Catalysts: Efficient Oxidative Dehydrogenation of N-Heterocycles
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An important goal for nanocatalysis is the development of flexible and efficient methods for preparing active and stable core-shell catalysts. In this respect, we present the synthesis and characterization of iron oxides surrounded by nitrogen-doped-graphene shells immobilized on carbon support (labeled FeOx@NGr-C). Active catalytic materials are obtained in a simple, scalable and two-step method via pyrolysis of iron acetate and phenanthroline and subsequent selective leaching. The optimized FeOx@NGr-C catalyst showed high activity in oxidative dehydrogenations of several N-heterocycles. The utility of this benign methodology is demonstrated by the synthesis of pharmaceutically relevant quinolines. In addition, mechanistic studies prove that the reaction progresses via superoxide radical anions (·O2-).
- Cui, Xinjiang,Li, Yuehui,Bachmann, Stephan,Scalone, Michelangelo,Surkus, Annette-Enrica,Junge, Kathrin,Topf, Christoph,Beller, Matthias
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supporting information
p. 10652 - 10658
(2015/09/28)
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- Olefin Metathesis
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The present invention relates to pre-catalysts for olefin metathesis and composition involving these pre-catalysts.
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Page/Page column
(2014/08/07)
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- Silver-catalyzed oxidative coupling of aniline and ene carbonyl/acetylenic carbonyl compounds: An efficient route for the synthesis of quinolines
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An efficient silver-mediated coupling of aniline with ene carbonyl/acetylenic carbonyl compounds for the synthesis of quinolines is reported. The transformation is effective for a broad range of substrates, thus enabling the expansion of substituent architectures on the heterocyclic framework. The electronic properties of the substituents on the amine have been investigated. It was found that molecules with both electron-donating and electron-withdrawing substituents were suitable substrates for this transformation, and the expected products were obtained in moderate to excellent yields. The use of a single catalytic system to mediate chemical transformations in a synthetic operation is important for the development of new atom-economic strategies and this strategy is efficient in building complex structures from simple starting materials in an environmentally benign fashion.
- Zhang, Xu,Xu, Xuefeng
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supporting information
p. 3089 - 3093
(2015/02/19)
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- Quinoline and phenanthroline preparation starting from glycerol via improved microwave-assisted modified Skraup reaction
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An efficient "green" modified Skraup reaction in neat water was developed using inexpensive, abundant and environmentally-friendly glycerol under microwave irradiation conditions. Starting from aniline derivatives, various quinolines were obtained in 10-66% yields. The use of nitroaniline led to the corresponding phenanthrolines in 15-52% yields, respectively. This journal is the Partner Organisations 2014.
- Saggadi, Hanen,Luart, Denis,Thiebault, Nicolas,Polaert, Isabelle,Estel, Lionel,Len
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p. 21456 - 21464
(2014/06/10)
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- Cesium carbonate mediated aryl triflate esters' deprotection
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A variety of diversely substituted aryl triflate esters were efficiently deprotected to the parent phenols by exposure to cesium carbonate in toluene. This procedure proved highly compatible with existing functional groups.
- Green, Alice E.,Agouridas, Vangelis,Deniau, Eric
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supporting information
p. 7078 - 7079
(2013/12/04)
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- Microwave-assisted copper-catalyzed hydroxylation of aryl halides in water
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A simple and efficient protocol for microwave-assisted copper-catalyzed hydroxylation of aryl halides is developed. A variety of phenols can be obtained in moderate to excellent yields of up to 95%. Its application is performed to synthesize 2,3-dihydroxy-1,4-naphthoquinone, which displays significant anti-proliferation effect.
- Ke, Fang,Chen, Xiaole,Li, Zhengkai,Xiang, Haifeng,Zhou, Xiangge
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p. 22837 - 22840
(2013/11/19)
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- Pd2dba3/Bippyphos: A robust catalyst system for the hydroxylation of aryl halides with broad substrate scope
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A mixture of tris(dibenzylideneacetone)dipalladium(0) (Pd 2dba3) and 5-(di-tert-butylphosphino)-1′,3′, 5′-triphenyl-1′H-[1,4′]bipyrazole (Bippyphos) is shown to be a robust and efficient catalyst system for the hydroxylation of structurally diverse (hetero)aryl halides under mild conditions and with broad substrate scope. Included in this reactivity survey is the successful synthesis of substituted benzofurans and related heteroatomic derivatives, which are formed via the hydroxylation of 2-haloalkynylarenes. Notably, a significant number of the reactions reported herein proceed at room temperature, and we have demonstrated that it is possible to conduct reactions on the benchtop under air using unpurified solvents with negligible loss in reactivity versus related transformations conducted under inert atmosphere conditions. We also report herein the first crystallographically characterized (Bippyphos)Pd(II) complex, which confirms the ability of this synthetically useful ligand to adopt a bidentate binding motif in a manner similar to Buchwald's biarylphosphine ligand class. Copyright
- Lavery, Christopher B.,Rotta-Loria, Nicolas L.,McDonald, Robert,Stradiotto, Mark
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supporting information
p. 981 - 987
(2013/05/08)
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- Glycosylated copper(ii) ionophores as prodrugs for β-glucosidase activation in targeted cancer therapy
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8-Hydroxyquinoline derivatives are metal-binding compounds that have recently attracted interest as therapeutic agents for cancer therapy. In this scenario, we designed and synthesized three new glucoconjugates, 5,7-dichloro-8-quinolinyl-β-d-glucopyranoside, 5-chloro-8-quinolinyl- β-d-glucopyranoside and 2-methyl-8-quinolinyl-β-d-glucopyranoside and investigated their biological properties in comparison to the parent 8-hydroxyquinoline derivatives in the presence of Cu2+. In vitro data show that 2 out of 3 glycosylated compounds possess a pharmacologically- relevant antiproliferative activity against tumor cells, similar to that of their parent compounds; this activity is associated with a relevant triggering of apoptosis. The pharmacological profile of the glucoconjugates depends on the cellular enzymatic β-glucosidase activity, as demonstrated by the inhibition of antiproliferative activity in the presence of the 2,5-dideoxy-2,5-imino-d-mannitol. The Royal Society of Chemistry 2013.
- Oliveri, Valentina,Viale, Maurizio,Caron, Giulia,Aiello, Cinzia,Gangemi, Rosaria,Vecchio, Graziella
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p. 2023 - 2034
(2013/03/14)
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- PROCHELATORS USEFUL FOR INHIBITING METAL-ASSOCIATED TOXICITY
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Prochelator compounds of Formula (I) or Formula (II) are described, along with methods of using the same and pharmaceutical formulations or compositions containing the same.
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Page/Page column 22-26
(2011/02/24)
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- Investigation of self-immolative linkers in the design of hydrogen peroxide activated metalloprotein inhibitors
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A series of self-immolative boronic ester protected methyl salicylates and metal-binding groups with various linking strategies have been investigated for their use in the design of matrix metalloproteinase proinhibitors.
- Jourden, Jody L. Major,Daniel, Kevin B.,Cohen, Seth M.
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supporting information; experimental part
p. 7968 - 7970
(2011/08/07)
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- STIMULUS-TRIGGERED PRODRUGS
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Set forth herein, inter alia, are compositions and methods for treating diseases with prodrugs. Provided herein are prodrug compositions for inhibiting the function of proteins, compositions and methods for treating diseases associated with oxidative compounds, oxidatively-sensitive prodrugs of inhibitors of metalloproteases. and methods of inhibiting metalloproteases using oxidatively-sensitive prodrugs.
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Page/Page column 54-56
(2012/01/13)
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- Palladium-catalysed reactions of 8-hydroxy- and 8-benzyloxy-5,7- diiodoquinoline under aminocarbonylation conditions
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Various 5-carboxamido-7-iodo-8-benzyloxyquinolines were synthesised via selective aminocarbonylation of 5,7-diiodo-8-benzyloxyquinoline in the presence of 'in situ' generated palladium(0) catalysts. Under similar conditions (50 °C, 80 bar CO), 5,7-bis(N-tert-butyl-glyoxylamido)-8-hydroxyquinoline was obtained using tert-butylamine as N-nucleophile. The unprotected 5,7-diiodo-8-hydroxyquinoline underwent dehydroiodination resulting in 8-hydroxyquinoline as the major product.
- Takács, Attila,Szilágyi, Antal,ács, Péter,Márk, László,Peixoto, Andreia F.,Pereira, Mariette M.,Kollár, László
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experimental part
p. 2402 - 2406
(2011/04/26)
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