- Photosensitized Desulfurization of Heterocyclic Thioketones and Its Accompanied Chemiluminescence
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Photosensitized oxygenation of 10-methyl-9(10H)-acridinethione, 9H-xanthene-9-thione, and 9H-thioxanthene-9-thione at -78 deg C gave the corresponding ketones, 10-methyl-9(10H)-acridinone, 9H-xanthen-9-one, and 9H-thioxanthen-9-one quantitatively in a 3-10 min-irradiation.Weak chemiluminescence was observed from the irradiated solution upon warming-up.
- Suzuki, Nobutaka,Sano, Kaniti,Wakatsuki, Satoshi,Tani, Noriyuki,Izawa, Yasuji
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Read Online
- Synthesis of xanthones, thioxanthones and Acridones by a metal-free photocatalytic oxidation using visible light and molecular oxygen
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9H-Xanthenes, 9H-thioxanthenes and 9,10-dihydroacridines can be easily oxidized to the corresponding xanthones, thioxanthones and acridones, respectively, by a simple photo-oxidation procedure carried out using molecular oxygen as oxidant under the irradiation of visible blue light and in the presence of riboflavin tetraacetate as a metal-free photocatalyst. The obtained yields are high or quantitative.
- Chinchilla, Rafael,Torregrosa-Chinillach, Alejandro
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- Cu2O-CuO/Chitosan Composites as Heterogeneous Catalysts for Benzylic C?H Oxidation at Room Temperature
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Recently, in catalysis, chitosan has been exploited as a macrochelating ligand for metal active species due to the presence of various functional groups in its structure. Moreover, copper-based catalysts are classified as one of the most environmentally friendly catalytic systems and their use for the oxidation of alkylarene has not been established much. Therefore, in this work, the hydrothermal synthesis of copper oxide-chitosan composites as heterogeneous catalysts for the benzylic C?H oxidation of alkylarene was investigated. Characterization results reveal mixed phases of CuO and Cu2O, inferring the ability of chitosan to act as a reducing sugar under the hydrothermal condition. The pre-existing interaction between copper species and chitosan as well as the co-existence of the Cu2O and CuO structures give rise to the efficient performance of the catalysts. The synthesized composites exhibit high activity for the oxidation of fluorene to 9-fluorenone at room temperature and small catalyst loading (1 mol % of Cu, >90 % conversion and 100 % selectivity). Superior TOF was observed, and a good scope of substrates can be converted to corresponding ketones in 48–97 % yields with these copper oxide-chitosan catalysts. In addition, the catalysts can be used for up to nine cycles without significant decrease of the activity.
- Kanarat, Jurin,Bunchuay, Thanthapatra,Klysubun, Wantana,Tantirungrotechai, Jonggol
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p. 4833 - 4840
(2021/10/07)
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- Ultraviolet-light-induced aerobic oxidation of benzylic C(sp3)-H of alkylarenes under catalyst- and additive-free conditions
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A mild and efficient system has been discovered for the synthesis of α-aryl carbonyl compounds via oxidation of benzylic C–H to C[dbnd]O bonds. This ultraviolet-light-mediated oxygenation reaction exhibited excellent substrate scope including various xanthenes, thioxanthenes and 9, 10-dihydroacridines and afforded the corresponding ketones with good to excellent yields under catalyst- and additive-free conditions at room temperature.
- Zhou, Jiacheng,Li, Meichao,Li, Tianci,Li, Chunmei,Hu, Xinquan,Jin, Liqun,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu
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- HCl-Catalyzed Aerobic Oxidation of Alkylarenes to Carbonyls
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The construction of C?O bonds through C?H bond functionalization remains fundamentally challenging. Here, a practical chlorine radical-mediated aerobic oxidation of alkylarenes to carbonyls was developed. This protocol employed commercially available HCl as a hydrogen atom transfer (HAT) reagent and air as a sustainable oxidant. In addition, this process exhibited excellent functional group tolerance and a broad substrate scope without the requirement for external metal and oxidants. The mechanistic hypothesis was supported by radical trapping, 18O labeling, and control experiments.
- Ding, Ling,Liu, Yuxiu,Niu, Kaikai,Shi, Xiaodi,Song, Hongjian,Wang, Qingmin
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- COMPOUND FOR ORGANIC ELECTRONIC ELEMENT, ORGANIC ELECTRONIC ELEMENT USING THE SAME, AND AN ELECTRONIC DEVICE THEREOF
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The present invention provides a novel compound that can improve the luminous efficiency, stability and life span of the element, an organic electronic element using the same, and an electronic device thereof.
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Paragraph 0097; 0099; 0103; 0105
(2021/05/21)
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- Poly(ethylene glycol) dimethyl ether mediated oxidative scission of aromatic olefins to carbonyl compounds by molecular oxygen
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A simple, and practical oxidative scission of aromatic olefins to carbonyl compounds using O2as the sole oxidant with poly(ethylene glycol) dimethyl ether as a benign solvent has been developed. A wide range of monosubstituted,gem-disubstituted, 1,2-disubstituted, trisubstituted and tetrasubstituted aromatic olefins was successfully converted into the corresponding aldehydes and ketones in excellent yields even with gram-scale reaction. Some control experiments were also conducted to support a possible reaction pathway.
- Yu, Tao,Guo, Mingqing,Wen, Simiaomiao,Zhao, Rongrong,Wang, Jinlong,Sun, Yanli,Liu, Qixing,Zhou, Haifeng
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p. 13848 - 13852
(2021/04/22)
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- Method for preparing aldehyde ketone compound through olefin oxidation
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The invention provides a method for preparing an aldehyde ketone compound by olefin oxidation, which relates to an olefin oxidative cracking reaction in which oxygen participates. The method comprises the following specific steps: in the presence of a solvent and an oxidant, carrying out oxidative cracking on an olefin raw material to obtain a corresponding aldehyde ketone product. Compared with the traditional method, the method does not need to add any catalyst or ligand, does not need to use high-pressure oxygen, has the advantages of simple and mild reaction conditions, environment friendliness, low cost, high atom economy and the like, is wide in substrate application range and high in yield, and has a wide application prospect in the aspects of synthesis of aldehyde ketone medical intermediates and chemical raw materials.
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Paragraph 0019
(2021/04/07)
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- Formation and Disproportionation of Xanthenols to Xanthenes and Xanthones and Their Use in Synthesis
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A facile and versatile strategy employing TiCl4-mediated cyclization followed by a Cannizzaro reaction has been developed for the synthesis of various xanthene derivatives. The reaction proceeded smoothly to afford both xanthenes/xanthones or their sulfur derivatives and tolerated a wide range of electronically diverse substrates. Using this methodology, pranoprofen was synthesized in three steps in 59% overall yield from commercially available starting materials.
- Shi, Zeyu,Chen, Si,Xiao, Qiong,Yin, Dali
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p. 3334 - 3343
(2021/02/05)
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- Scalable electrochemical reduction of sulfoxides to sulfides
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A scalable reduction of sulfoxides to sulfides in a sustainable way remains an unmet challenge. This report discloses an electrochemical reduction of sulfoxides on a large scale (>10 g) under mild reaction conditions. Sulfoxides are activated using a substoichiometric amount of the Lewis acid AlCl3, which could be regeneratedviaa combination of inexpensive aluminum anode with chloride anion. This deoxygenation process features a broad substrate scope, including acid-labile substrates and drug molecules.
- Kong, Zhenshuo,Pan, Chao,Li, Ming,Wen, Lirong,Guo, Weisi
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supporting information
p. 2773 - 2777
(2021/04/21)
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- COMPOUND FOR ORGANIC ELECTRONIC ELEMENT, ORGANIC ELECTRONIC ELEMENT USING THE SAME, AND AN ELECTRONIC DEVICE THEREOF
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The present invention provides a compound represented by chemical formula 1, an organic electric device including a first electrode, a second electrode, and an organic material layer between the first electrode and the second electrode, and an electronic device including the organic electric device. By including the compound represented by chemical formula 1 in the organic material layer, the driving voltage of the organic electric device can be lowered, luminous efficiency and lifespan can be improved, and in particular, the lifespan can be improved.COPYRIGHT KIPO 2021
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Paragraph 0144; 0238; 0247-0248; 0251-0252
(2020/10/31)
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- Ultraviolet light promoted synthesis method of thioxanthone compounds
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The invention discloses an ultraviolet light promoted synthesis method of a thioxanthone compound. The preparation method comprises the following steps: carrying out a reaction in 1,2-dichloroethane at normal temperature under the condition of 380-385 nm ultraviolet irradiation by taking a thioxanthone compound as a reaction substrate and taking oxygen in air as an oxidizing agent, and after the reaction is finished, carrying out separation treatment to obtain the thioxanthone compound. According to the synthesis method disclosed by the invention, the traditional heating reaction is replaced by an illumination reaction, so that energy sources can be saved, and any catalyst is not used.
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Paragraph 0023-0024
(2020/06/02)
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- Benzylic oxidation and functionalizations of xanthenes by ligand trasfer reactions of hypervalent iodine reagents
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The benzylic oxidation, amidation, and unprecedented heteroarylation proceed at room temperature using iodosobenzene, (sulfonylimido)iodobenzenes, and diaryliodonium(III) salts are described for the direct Csp3-H functionalizations of xanthene molecules. This study has demonstrated that hypervalent iodine reagents serve as unified synthetic tools for versatile xanthene Csp3-H transformations based on the radical and SET oxidation processes.
- Dohi, Toshifumi,Ito, Motoki,Kita, Yasuyuki,Komiyama, Keina,Ueda, Shohei,Yamaoka, Nobutaka
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- Synthesis of dibenzocycloketones by acyl radical cyclization from aromatic carboxylic acids using methylene blue as a photocatalyst
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An efficient intramolecular radical cyclization reaction via photoredox catalysis was developed for the synthesis of dibenzocycloketone derivatives using methylene blue as a photosensitizer. This strategy could be widely used to synthesize large heterocycles due to the unique reactivity of phosphoranyl radicals formed by a polar/SET crossover between an aromatic carboxylic acid and a phosphine radical cation. Attractive features of this process include generation of an acyl radical by an inexpensive and metal-free photocatalyst, which effectively undergoes a cyclization process.
- Jiang, Hongshuo,Mao, Guijie,Wu, Hongfeng,An, Qi,Zuo, Minghui,Guo, Weihao,Xu, Chunzhao,Sun, Zhizhong,Chu, Wenyi
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supporting information
p. 5368 - 5373
(2019/10/11)
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- Visible-Light-Induced Aerobic Oxidation of Benzylic C(sp 3)-H of Alkylarenes Promoted by DDQ, tert -Butyl Nitrite, and Acetic Acid
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A visible-light photocatalytic aerobic oxidation of benzylic C(sp 3)-H bonds proceeded in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, tert -butyl nitrite, and acetic acid. Advantages of this aerobic oxidation method include its relatively mild conditions, the use of visible-light irradiation instead of conventional thermal methods, the use of a low catalyst loading, and the ability to oxidize a range of alkylarenes, including xanthenes, thioxanthenes, and 9,10-dihydroacridines, to the corresponding ketones in excellent yields.
- Pan, Decheng,Wang, Yiqing,Li, Meichao,Hu, Xinquan,Sun, Nan,Jin, Liqun,Hu, Baoxiang,Shen, Zhenlu
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p. 218 - 224
(2019/01/14)
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- A sulfur mixed anthracene compound photocatalytic oxidation synthesis method (by machine translation)
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The present invention discloses a sulfur mixed anthracene compound photocatalytic oxidation synthesis method, sulfur mixed anthracene compound as a reaction substrate, in order to 2, 3 - dichloro - 5, 6 - dinitrile - 1, 4 - benzoquinone (DDQ) and tert-butyl nitrite (TBN) as catalyst, in order to acetic acid as the reaction additive, to oxygen as the oxidizing agent, the reaction substrate in 1, 2 - dichloroethane in the solvent, and the blue light illumination at normal temperature and under the conditions of reaction, after the reaction is completed after the separation and processed to obtain the sulfur mixed anthracene compound. The synthesizing method of the invention, in order to light the reaction to replace the traditional heating reaction, the energy can be saved; without the use of a transition metal catalyst; under the condition of optimizing, the yield is high. (by machine translation)
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Paragraph 0024-0039
(2019/02/04)
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- A g-C3N4-based heterogeneous photocatalyst for visible light mediated aerobic benzylic C-H oxygenations
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A metal-free heterogeneous photocatalytic system has been developed for highly efficient benzylic C-H oxygenations using oxygen as an oxidant. This visible light mediated oxidation reaction utilizes graphitic carbon nitride (g-C3N4) as a recyclable, nontoxic and low cost photocatalyst. Mild reaction conditions allow for the generation of synthetically and biologically valued isochromannones, phthalides, isoquinolinones, isoindolinones and xanthones from readily accessible alkyl aromatic precursors in good yields. The heterogeneous nature of the g-C3N4 catalytic system enables easy recovery and recycling as well as the use in multiple runs without loss of activity. The synthetic utility of this "green" methodology was further demonstrated by applying in bioactive and drug valued target syntheses.
- Geng, Pengxin,Tang, Yurong,Pan, Guanglong,Wang, Wentao,Hu, Jinchuan,Cai, Yunfei
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supporting information
p. 6116 - 6122
(2019/11/20)
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- Thiolate-Initiated Synthesis of Dibenzothiophenes from 2,2′-Bis(methylthio)-1,1′-Biaryl Derivatives through Cleavage of Two Carbon-Sulfur Bonds
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A catalytic reaction involving the cleavage of two carbon-sulfur bonds in 2,2′-bis(methylthio)-1,1′-biaryl derivatives is reported. This reaction does not require a transition-metal catalyst and is promoted by a thiolate anion. Notably, based on DFT calculations, the product-forming cyclization step is shown to proceed through a concerted nucleophilic aromatic substitution (CS N Ar) mechanism.
- Chatani, Naoto,Kawashima, Yuki,Kodama, Takuya,Masuya, Yoshihiro,Tobisu, Mamoru
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supporting information
p. 1995 - 1999
(2019/10/22)
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- A molybdenum based metallomicellar catalyst for controlled and chemoselective oxidation of activated alcohols in aqueous medium
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A surfactant based oxodiperoxo molybdenum complex, which could activate molecular oxygen, has been employed as a catalyst for controlled oxidation of benzylic alcohols to corresponding carbonyls. The oxidation reactions were carried out under aqueous environment, however, in the absence of any extraneous base or co-catalyst. Sensitive/oxidizable functional groups like cyano, sulfide, hydroxyl, aryl-hydroxyl, alkene (internal/terminal), alkyne (internal/terminal), and acetal were tolerated during the transformations. Such selectivity is attributed to the mild nature of the catalyst. The methodology could also be scaled-up for multi-gram synthesis and the protocol is likely to find practical use since it requires an inexpensive recyclable-catalyst and easily available oxidant (under green conditions). A plausible mechanism is proposed with the help of preliminary computational study.
- Thiruvengetam, Prabaharan,Chakravarthy, Rajan Deepan,Chand, Dillip Kumar
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p. 123 - 133
(2019/07/19)
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- π-Expanded Thioxanthones – Engineering the Triplet Level of Thioxanthone Sensitizers for Lanthanide-Based Luminescent Probes with Visible Excitation
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Bright lanthanide based probes for optical bioimaging must rely on the antenna principle, where the lanthanide-centred excited state is formed by a complex sensitization process. Efficient sensitization of lanthanide-centred emission occurs via triplet states centred on the sensitizing chromophore. Here, the triplet state of thioxanthone chromophores is modulated by extending the π-system. Three thioxanthone chromophores-thioxanthone, benzo[c]thioxanthone, and naphtho[2,3-c]thioxanthone were synthesised and characterised. The triplet state energies and lifetimes is found to change as expected, and two dyes are found to be suitable sensitizers for europium(iii) luminescence. Reactive derivatives of thioxanthone and benzo[c]thioxanthone were prepared and coupled to a 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A) lanthanide binding pocket. The photophysics and the performance in optical bioimaging of the resulting europium(iii) complexes were investigated. It is concluded that while the energetics favour efficient sensitization, the solution structure does not. While it was found that the complexes are too lipophilic to be efficient luminescent probes for optical bioimaging, we successfully demonstrated bioimaging using europium(iii) luminescence following 405 nm excitation.
- Dansholm, Charlotte Nybro,Junker, Anne Kathrine R.,Nielsen, Lea G.,Kofod, Nicolaj,Pal, Robert,S?rensen, Thomas Just
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p. 1778 - 1788
(2019/07/15)
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- Synthesis method of thioether compounds
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The invention discloses a synthesis method of thioether compounds. The method comprises steps as follows: phosphorus trichloride and a solvent with uniformly distributed sulfoxide compounds are mixeduniformly, after mixing, the mixture is subjected to a reaction at the temperature of 20-25 DEG C for 0.5-6 h, and the thioether compounds are obtained, wherein the solvent is acetonitrile. Compared with the prior art, the synthesis method has the advantages that raw materials are cheap and easy to obtain, a reducer is cheap and easy to obtain and store, and a series of thioether compounds can beobtained.
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Paragraph 0137-0141
(2019/08/02)
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- Nitric acid-catalyzed aerobic oxidation of benzylic sp3 C–H bonds of isochromans, xanthenes and 9-fluorenone under additive-free conditions
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HNO3 was demonstrated to be an effective catalyst for aerobic oxidation of benzylic sp3 C–H bonds under additive-free conditions. A series of isochromans, xanthenes and fluorenes underwent this transformation to give the targeted products in low to high yields under the catalysis of HNO3, which provided an effective method for the synthesis of the synthetically and biologically valued isochromanones, xanthones and 9-fluorenones.
- Tian, Xinzhe,Ren, Fangping,Zhao, Bo,Ren, Yun-Lai,Zhao, Shuang,Wang, Jianji
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- Deoxygenation of sulphoxides to sulphides with trichlorophosphane
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An efficient route to deoxygenation of sulphoxides to sulphides with PCl3 under mild reaction condition was developed. PCl3 was used as a reducing agent for the first time to convert sulphoxides to sulphides. The mild conditions, use of cheap and readily available reagent, and broad substrate scope render it a useful strategy for preparing sulphides.
- Zhao, Xia,Zheng, Xiancai,Yang, Bo,Sheng, Jianqiao,Lu, Kui
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p. 1200 - 1204
(2018/02/21)
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- Method for catalytic oxidization synthesis of anthone compound
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The invention discloses a method for catalytic oxidation synthesis of an anthone compound. The method is carried out according to the following steps: adding an anthene compound, Fe(NO3)3*9H2O and a fluorine-containing inorganic salt into an acetonitrile solvent, and performing a reaction for 2-12h at 75-85 DEG C under a normal pressure oxygen condition to obtain the anthone compound, wherein the mass ratio of the reaction substrate namely the anthone compound, Fe(NO3)3*9H2O and the fluorine-containing inorganic salt is 100:(8-15):(15-30), and after the completion of the reaction, the anthone compound can be obtained by adopting conventional column separation purification. The method provided by the invention is simple, convenient and safe to operate, and has the following beneficial effects: A) clean oxygen is used as an oxidant in the method, so that the environmental cost is greatly reduced; and B) Fe(NO3)3*9H2O is used as a catalyst in the method, so that the cost is low.
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Paragraph 0041
(2017/07/21)
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- CBr4 promoted intramolecular aerobic oxidative dehydrogenative arylation of aldehydes: application in the synthesis of xanthones and fluorenones
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A simple and practical carbon tetrabromide promoted intramolecular aerobic oxidative dehydrogenative coupling reaction has been developed to provide a straightforward ring closure protocol for 2-aryloxybenzaldehydes to furnish xanthones. The reaction was performed under metal-, additive- and solvent-free conditions with good tolerance of functional groups. The present method is also applicable to the synthesis of fluorenones by using 2-arylbenzaldehydes as substrates. Preliminary studies of the reaction mechanism indicated that the reaction may proceed through a radical pathway.
- Tang, Jing,Zhao, Shijun,Wei, Yuanyuan,Quan, Zhengjun,Huo, Congde
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supporting information
p. 1589 - 1592
(2017/02/23)
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- Quetiapine synthesizing method
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The invention discloses a quetiapine synthesizing method. O-chlorobenzoic acid with the low price is adopted as a starting material to react with thiophenol, and then ring closure is performed to obtain thioxanthone. Hydroxyl amination and Beckmann rearrangement are performed to obtain a key intermediate dibenzo[b,f][1,4]thiazepines-11-(10H)one, chlorination is performed, then, a reaction is performed on 1-(2-hydroxyethoxy)ethylpiperazine with the existence of acid-binding agent to obtain quetiapine, and the quetiapine and fumaric acid form a salt in an absolute ethyl alcohol system to obtain a product. According to the quetiapine synthesizing method, raw materials are low in price and easy to obtain, the steps are simple, operation is easy, and the cost can be effectively lowered. According to the method, the high-purity quetiapine can be obtained, the liquid phase purity of the obtained semi-fumaric acid quetiapine obtained through salt forming is 99% or above, and the quetiapine synthesizing method can be applied to the field of medicine.
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Paragraph 0064; 0065
(2017/06/27)
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- C-H Photooxygenation of Alkyl Benzenes Catalyzed by Riboflavin Tetraacetate and a Non-Heme Iron Catalyst
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A mixture of the photocatalyst riboflavin tetraacetate (RFT) and the biomimetic non-heme iron complex [Fe(TPA)(MeCN)2](ClO4)2 (TPA=tris(2-pyridylmethyl)amine) efficiently catalyzes the visible-light-driven aerobic oxidation of alkyl benzenes to ketones and carboxylic acids. An RFT-catalyzed photocycle and the independent action of the iron complex as a catalyst for H2O2 disproportionation and alkyl benzene oxygenation ensure high yields and selectivities.
- Mühldorf, Bernd,Wolf, Robert
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supporting information
p. 427 - 430
(2016/01/25)
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- Hydrodeoxygenation of sulfoxides to sulfides by a Pt and MoOx co-loaded TiO2 catalyst
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Supported metal nanoparticle catalysts were studied for the hydrodeoxygenation of sulfoxides to sulfides under solvent-free and mild conditions (50-155 °C, 1 or 7 atm H2). The catalytic activity for the model reaction of diphenyl sulfoxide depended on the type of metals, support materials and co-loaded oxides of transition metals (V, Nb, Mo, W, Re). Pt and MoOx co-loaded TiO2 (Pt-MoOx/TiO2) showed the highest activity. Pt-MoOx/TiO2 was reusable after the reaction and was effective for the reduction of various sulfoxides and showed a higher turnover number (TON) than previously reported catalysts. Using Pt-MoOx/TiO2, benzylphenylsulfone was reduced by H2 to give phenylbenzyl sulfide via benzylphenyl sulfoxides, which represented the first example of catalytic conversion of a sulfone to a sulfide by H2. Characterization studies of Pt-MoOx/TiO2 show that the surface of TiO2 is covered by small (or thin layer) Mo oxide species with exposed Mo cations as Lewis acid sites, and 4-5 nm sized Pt metal nanoparticles are supported on the Mo oxide-covered TiO2.
- Touchy, Abeda Sultana,Hakim Siddiki,Onodera, Wataru,Kon, Kenichi,Shimizu, Ken-Ichi
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p. 2554 - 2560
(2016/05/19)
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- Organocatalytic Aerobic Oxidation of Benzylic sp3 C-H Bonds of Ethers and Alkylarenes Promoted by a Recyclable TEMPO Catalyst
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An entirely metal-free catalyst system consisting of an easily prepared recyclable new TEMPO derived sulfonic salt catalyst, and mineral acids (NaNO2 and HCl) has been developed for selective aerobic oxidation of structurally diverse benzylic sp3 C-H bonds of ethers and alkylarenes. The mild reaction conditions allow for the generation of synthetically and biologically valued isochromanones and xanthones from readily accessible alkyl aromatic precursors in good yields.
- Zhang, Zhiguang,Gao, Yuan,Liu, Yuan,Li, Jianjun,Xie, Hexin,Li, Hao,Wang, Wei
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supporting information
p. 5492 - 5495
(2015/11/18)
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- Aerobic oxidation of alcohols by using a completely metal-free catalytic system
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A metal-free reaction system of air, NH4NO3(cat), 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)(cat), and H +(cat) is introduced as a simple, safe, inexpensive, efficient and chemoselective mediator for aerobic oxidation of various primary and secondary benzyl and alkyl alcohols, including those bearing oxidizable heteroatoms (N, S, O) to the corresponding aldehydes or ketones. Air oxygen under slight overpressure plays the role of the terminal oxidant, which is catalytically activated by redox cycles of nitrogen oxides released from a catalytic amount of NH4NO3 and cocatalyzed by TEMPO (nitroxyl radical compound), under acidic conditions, which are essential for an overall activation of the reaction system. The synthetic value of this reaction system and its green chemical profile was illustrated by a 10 g scale-up experiment, performed in an open-air system by using a renewable and reusable polymer-supported form of TEMPO (OXYNITROXS100). The reaction solvent was recovered by distillation under atmospheric pressure, and the pure final product was isolated under reduced pressure; the acid activators (HCl or H 2SO4) were recovered as ammonium salts. A metal-free reaction system of air/NH4NO3(cat)/TEMPO (cat)/H+(cat) is introduced as a simple, safe, inexpensive, efficient and chemoselective mediator for aerobic oxidation of various primary and secondary benzyl, alkyl and allyl alcohols, including those bearing oxidizable heteroatoms (N, S, O) to the corresponding aldehydes or ketones. Copyright
- Prebil, Rok,Stavber, Gaj,Stavber, Stojan
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supporting information
p. 395 - 402
(2014/01/23)
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- Aerobic Oxidation of Alcohols by Using a Completely Metal-Free Catalytic System
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A metal-free reaction system of air, NH4NO3(cat), 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)(cat), and H+(cat) is introduced as a simple, safe, inexpensive, efficient and chemoselective mediator for aerobic oxidation of various primary and secondary benzyl and alkyl alcohols, including those bearing oxidizable heteroatoms (N, S, O) to the corresponding aldehydes or ketones. Air oxygen under slight overpressure plays the role of the terminal oxidant, which is catalytically activated by redox cycles of nitrogen oxides released from a catalytic amount of NH4NO3 and cocatalyzed by TEMPO (nitroxyl radical compound), under acidic conditions, which are essential for an overall activation of the reaction system. The synthetic value of this reaction system and its green chemical profile was illustrated by a 10 g scale-up experiment, performed in an open-air system by using a renewable and reusable polymer-supported form of TEMPO (OXYNITROXS100). The reaction solvent was recovered by distillation under atmospheric pressure, and the pure final product was isolated under reduced pressure; the acid activators (HCl or H2SO4) were recovered as ammonium salts.
- Prebil, Rok,Stavber, Gaj,Stavber, Stojan
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supporting information
p. 395 - 402
(2015/10/05)
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- AIBN-catalyzed oxidative cleavage of gem -disubstituted alkenes with O 2 as an oxidant
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A 2,2-azobis(isobutyronitrile) (AIBN) catalyzed oxidative cleavage of gem-disubstituted alkenes with molecular oxygen as the oxidant has been described. Carbonyl compounds were obtained as the desired products in high yield under mild conditions. Based on previous documents and current experimental results, a relatively reasonable mechanism is proposed.
- Wang, Guang-Zu,Li, Xing-Long,Dai, Jian-Jun,Xu, Hua-Jian
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p. 7220 - 7225
(2014/08/18)
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- A convenient synthesis of 9H-thioxanthen-9-ones and their aza-analogues
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An efficient method for the preparation of 9H-thioxanthen-9-ones and their three aza-analogues has been developed. The reaction of (2-fluorophenyl)(2- halophenyl)methanones, derived from 1-bromo-2-fluorobenzenes and 2- halobenzaldehydes by an easy two-step sequence, with Na2S· 9H2O in DMF at 60 °C gives 9H-thioxanthen-9-ones. This procedure can be applied to the synthesis of 5H-[1]benzothiopyrano[2,3-b](or [2,3-c])pyridin-5-ones or 10H-[1]-benzothiopyrano[3,2-c]pyridin-10-ones starting from 2-, 3- or 4-chloropyridines, respectively.
- Kobayashi, Kazuhiro,Komatsu, Toshihide,Nakagawa, Kazuhiro,Hara, Erika,Yuba, Shohei
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p. 2577 - 2587
(2014/01/06)
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- NaI/silica sulfuric acid as an efficient reducing system for deoxygenation of sulfoxides in poly ethylene glycol (PEG-200)
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Deoxygenation of structurally diverse sulfoxides including dialkyl, diaryl, aryl alkyl and allyl sulfoxides to the corresponding sulfides were carried out using a NaI/silica sulfuric acid reducing system at room temperature in poly ethylene glycol (PEG-200) in excellent yields.
- Zarei, Morteza,Ameri, Mohammad Aghil,Jamaleddini, Azar
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p. 259 - 263
(2013/08/26)
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- Oxidation of secondary benzylic alcohols to ketones and benzylic oxygenation of alkylarenes with hydrogen peroxide in the presence of activated carbon
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A variety of benzylic alcohols were oxidized to the corresponding carbonyl compounds selectively with 30% hydrogen peroxide (H in the presence of activated carbon. Alkylarenes such as fluorenes, xanthenes, and anthrone were also effectively oxygenated to the corresponding carbonyl compounds with 30% Has oxidant in the presence of activated carbon. Georg Thieme Verlag Stuttgart · New York.
- Nishida, Shunsuke,Hayashi, Masahiko
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experimental part
p. 1683 - 1685
(2012/08/13)
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- Synthesis of dihydrodibenzo[b,f]furo[2,3-d]oxepins and related reactions
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Nine dihydrodibenzo[b,f]furo[2,3-d]oxepin derivatives were synthesized by the Mn(III)-based oxidative addition of dibenz[b,f]oxepins at C10-C11 with acetic anhydride, acetylacetone, dialkyl malonates, and malonamide. Oxidative ring-expansion of methyl hydrogen thioxanthenylmalonate with manganese(III) acetate did not give the desired dibenzo[b,f]thiepincarboxylate but produced 2-acetoxy-2-(thioxanthen-9-yl)acetate and thioxanthone.
- Maemura, Yasunobu,Tanoue, Yuka,Nishino, Hiroshi
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p. 2491 - 2503,13
(2020/08/24)
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- TiCl4 hiocarbonyls and oxidation of sulfides in the presence of H2O2
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H2O2 in combination with TiCl4 proved to be a highly reactive reagent system for the desulfurization of thioamide and thioketone derivatives in excellent yields and short reaction times with high purity. Sulfides were also found to undergo oxidation to sulfones under similar reaction conditions. In most cases, these reactions are highly selective, simple, and clean, affording products in high yields and purity.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Shakibaian, Vida,Khaledian, Donya,Yousefi, Behrooz H.
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experimental part
p. 155 - 163
(2012/06/01)
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- Microwave-assisted, Yb(OTf)3/TfOH cocatalyzed synthesis of xanthones and thioxanthones by intramolecular friedel-crafts reaction under solvent-free conditions
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An efficient method for the synthesis of biologically interesting xanthones and thioxanthones was achieved using Yb(OTf)3/TfOH as co-catalysts by a microwave radiation-mediated reaction. Both electron-rich and electron-poor substrates could be cyclized in good yields.
- Li, Jie,Jin, Can,Su, Weike
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experimental part
p. 855 - 866
(2011/05/12)
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- Cyanuric chloride as promoter for the oxidation of sulfides and deoxygenation of sulfoxides
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This Letter discusses the use of cyanuric chloride as an efficient promoter for the chemoselective oxidation of sulfides to the corresponding sulfones in the presence of H2O2 as the terminal oxidant. Sulfoxides were also found to undergo deoxygenation to sulfides with cyanuric chloride and potassium iodide system. The reaction is broad in scope and easy to perform.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Sohrabnezhad, Samira
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experimental part
p. 6420 - 6423
(2011/12/21)
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- Trimethylsilyl chloride promoted selective desulfurization of thiocarbonyls to carbonyls with hydrogen peroxide
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In the presence of hydrogen peroxide and trimethylsilyl chloride, thiocarbonyls desulfurize to the corresponding carbonyls. The safe, operationally simple, general reaction gives excellent yields in short reaction times with no side reactions and excellent regioselectivity, which makes this process an attractive, environmentally benign alternative for the desulfurization of thiocarbonyls
- Bahrami, Kiumars,Khodaei, Mohammad Mehdi,Tajik, Maryam
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experimental part
p. 4282 - 4286
(2011/02/25)
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- TAPC-promoted oxidation of sulfides and deoxygenation of sulfoxides
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Figure presented. 1,3,5-Triazo-2,4,6-triphosphorine-2,2,4,4,6,6- tetrachloride (TAPC) was found to be an efficient promoter for the oxidation of sulfides and deoxygenation of sulfoxides. Excellent yields, short reaction time, easy and quick isolation of the products, solvent-free process, and excellent chemoselectivity are the main advantages of this procedure.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Sheikh Arabi, Mehdi
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supporting information; experimental part
p. 6208 - 6213
(2010/11/04)
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- H2O2/SOCl2: a useful reagent system for the conversion of thiocarbonyls to carbonyl compounds
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The H2O2/SOCl2 reagent system has been used as a new and efficient reagent for deprotection of thiocarbonyls to carbonyl compounds. The salient features of this protocol are short reaction times, good chemoselectivity, clean reaction profiles, and simple work-up that preclude the use of toxic solvents.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Farrokhi, Azita
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supporting information; experimental part
p. 7658 - 7661
(2009/12/04)
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- Clean and efficient benzylic C-H oxidation in water using a hypervalent iodine reagent: Activation of polymeric iodosobenzene with KBr in the presence of montmorillonite-K10
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(Chemical Equation Presented) We have found that unreactive and insoluble polymeric iodosobenzene [PhIO]n induced aqueous benzylic C-H oxidation to effectively give arylketones, in the presence of KBr and montmorillonite-K10 (M-K10) clay. Water-soluble and reactive species 1 having the unique I(III)-Br bond, in situ generated from [PhIO]n and KBr, was considered to be the key radical initiator during the reactions.
- Dohi, Toshifumi,Takenaga, Naoko,Goto, Akihiro,Fujioka, Hiromichi,Kita, Yasuyuki
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experimental part
p. 7365 - 7368
(2009/05/07)
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- Mild and efficient deoxygenation of sulfoxides to sulfides with triflic anhydride/potassium iodide reagent system
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It was found that the combination of triflic anhydride/potassium iodide was an effective promoter for the deoxygenation of sulfoxides and gave the corresponding sulfides in excellent yield in acetonitrile at room temperature. It is worth mentioning that this reagent system is chemoselective and tolerates various functional groups, such as alkene, ketone, ester, aldehyde, acid, and oxime. Georg Thieme Verlag Stuttgart.
- Bahrami, Kiumars,Khodaei, Mohammad Mehdi,Karimi, Ahmad
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experimental part
p. 2543 - 2546
(2009/04/04)
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- Synthesis of xanthones, thioxanthones, and acridones by the coupling of arynes and substituted benzoates
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The reaction of silylaryl triflates, CsF, and ortho-heteroatom-substituted benzoates affords a general and efficient way to prepare biologically interesting xanthones, thioxanthones, and acridones. This chemistry presumably proceeds by a tandem intermolecular nucleophilic coupling of the benzoate with an aryne and a subsequent intramolecular electrophilic cyclization.
- Zhao, Jian,Larock, Richard C.
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p. 583 - 588
(2007/10/03)
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- A novel method for the deoxygenation of sulfoxides with the PPh 3/Br2/CuBr system
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It was found that the combination of PPh3/Br2/CuBr was an effective promoter for the deoxygenation of sulfoxides and gave the corresponding sulfides in excellent yield in acetonitrile under refluxing conditions. It is worth mentioning that this reagent system is chemoselective, tolerating various functional groups such as carbon-carbon double bond and ketone. Copyright
- Bahrami, Kiumars,Khodaei, Mohammad Mehdi,Khedri, Mohammad
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p. 1324 - 1325
(2008/03/18)
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- Preparation of functionalized aryl magnesium reagents by the addition of magnesium aryl thiolates and amides to arynes
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(Chemical Equation Presented) Reactive arynes, which are readily generated by the reaction of ortho-iocloarylsulfonates with iPrMgCl, undergo the smooth addition of various magnesium nucleophiles like magnesium thiolates, selenides, and amides. In all cases the resulting functionalized aryl magnesium species can be trapped by an electrophile leading to highly functionalized aromatic compounds (see scheme).
- Lin, Wenwei,Sapountzis, Ioannis,Knochel, Paul
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p. 4258 - 4261
(2007/10/03)
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- One-pot synthesis of xanthones and thioxanthones by the tandem coupling-cyclization of arynes and salicylates
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(Chemical Equation Presented) The reaction of silylaryl triflates, CsF, and salicylates affords a general and efficient way to prepare biologically interesting xanthones and thioxanthones. This chemistry presumably proceeds by a tandem intermolecular nucleophilic coupling and subsequent intramolecular electrophilic cyclization.
- Zhao, Jian,Larock, Richard C.
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p. 4273 - 4275
(2007/10/03)
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- Benzylic oxygenation of alkylarenes with molecular oxygen in the presence of activated carbon
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A variety of alkylarenes such as fluorenes, xanthenes, and anthrone were effectively oxygenated to the corresponding carbonyl compounds with molecular oxygen as oxidant in the presence of activated carbon.
- Kawabata, Hirotoshi,Hayashi, Masahiko
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p. 5457 - 5459
(2007/10/03)
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- Nitrous oxide oxidation catalyzed by ruthenium porphyrin complex
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Dinitrogen oxide was employed as a clean oxidant for various oxidations in the presence of a catalytic amount of dioxoruthenium tetramesitylporphyrin complex (Ru(tmp)(O)2). A variety of olefins, secondary alcohols, and benzyl alcohols were smoothly oxidized to the corresponding epoxides, ketones, and aldehydes in high yields. In the oxidation of 9,10-dihydroanthracene derivatives, the competitive reactions affording anthraquinones and anthracenes could be regulated by the reaction conditions. At a high temperature (200°C), anthraquinones were selectively produced, while the anthracenes were selectively produced by the addition of sulfuric acid.
- Tanaka, Hirotaka,Hashimoto, Kentaro,Suzuki, Kyosuke,Kitaichi, Yasunori,Sato, Mitsuo,Ikeno, Taketo,Yamada, Tohru
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p. 1905 - 1914
(2007/10/03)
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- New method for the preparation of dibenzo[b,f][1,4]thiazepines
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The S-amination of 9H-thioxanthen-9-ol (2a) and 9-substituted derivatives 2b-e (Me (b), Et (c), iPr (d), Ph (e)) with O- mesitylenesulfonylhydroxylamine (MSH) was carried out. The expected product, 10-amino-9-hydroxy-9-isopropyl-9H-thioxanthenium mesitylenesulfonate (3d), was obtained in 78% yield from the corresponding thioxanthen-9-ol 2d. However, in the case of 2a-c and 2e the reaction led instead to dibenzo[b, f][1,4]thiazepines 6a-c and 6e in moderate yields.
- Fujii, Takayoshi,Hao, Wei,Yoshimura, Toshiaki
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p. 246 - 250
(2007/10/03)
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