- Base-free oxidation of alcohols enabled by nickel(ii)-catalyzed transfer dehydrogenation
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An efficient nickel(ii)-catalyzed transfer dehydrogenation oxidation of alcohols is reported that relies on cyclohexanone as the formal oxidant and does not require the use of an external base. The synthetic utility of this protocol is demonstratedviathe facile oxidation of structurally complicated natural products.
- Ye, Danfeng,Liu, Zhiyuan,Sessler, Jonathan L.,Lei, Chuanhu
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supporting information
p. 11811 - 11814
(2020/10/13)
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- ε-Caprolactone manufacture via efficient coupling Baeyer-Villiger oxidation with aerobic oxidation of alcohols
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To avoid the use of peracids oxidant or highly concentrated hydrogen peroxide which is potentially hazardous and explosive, herein, a new route to ε-caprolactone was developed in which molecule oxygen was employed as the terminal oxidant. The commercial available N-hydroxyphthalimide and ammonium cerium nitrate were used as the key catalysts for the increased yield of ε-caprolactone. For instance, the selectivity of ε-caprolactone was obtained 92 % with 85 % conversion of cyclohexanone which was comparable to the strategies using highly concentrated hydrogen peroxide. The sacrificed alcohols were transformed into corresponding ketones which were also valuable chemicals. Furthermore, the efficiency of the alcohols was achieved to unprecedented 52 %. The Baeyer-Villiger oxidation of various other cycloalkanones was also examined. The substituent group effect on the efficiency of sacrificed alcohols was investigated in which weak electron-donating substituent induced nearly quantitative yield of ε-caprolactone. The reaction mechanism was studied with the help of electron paramagnetic resonance which indicated the existence of a radical pathway.
- Du, Renfeng,Li, Haoran,Wang, Yongtao,Yao, Jia,Yuan, Haoran,Zhao, Chenxuan
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- Method for preparing symmetric diarylketone through catalytic oxidative carbonylation
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The invention discloses a method for preparing symmetric diarylketone of a formula (I) as shown in the description. The method comprises the following steps: mixing arylboronic acid (II) (Ar-B(OH)2 (II)), a palladium catalyst, a promoter and an organic solvent in a reactor, introducing air and CO having a volume ratio of (7-19):1, reacting under the conditions of a pressure of 1-6 atm and a temperature of 30-80 DEG C for 8-16 hours, and performing after-treatment on the reaction solution, thereby obtaining the product symmetric diarylketone. According to the method disclosed by the invention,the air directly serves as an oxidizing agent to replace the O2 to be applied to oxidative carbonylation of the arylboronic acid, and the ratio of the air to CO is beyond an explosion limit. Therefore, the catalytic system is safe and economic. The palladium catalyst is small in dosage and simple in separation and can be recycled for several times. The method disclosed by the invention is mild inreaction condition, excellent in substrate suitability and high in yield.
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Paragraph 0023; 0024; 0025; 0026; 0030
(2019/03/08)
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- A novel process for the synthesis of substantially pure Letrozole
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This article demonstrates an improved novel and practical synthesis of oral non-steroidal aromatase inhibitor (AI) Letrozole in a five-stage synthetic process in excellent yields. Key steps of the synthesis involve the condensation of 4-(chloro(4-cyanophenyl)methyl)benzamide with 1H-1,2,4-triazole and further its dehydration to Letrozole by using trifluoroacetic anhydride at low temperature.
- Suman,Vijayabhaskar,NageswaraRao,Syam Kumar,VenkateswaraRao
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- Palladium-Catalyzed Carbonylative Homocoupling of Aryl Iodides for the Synthesis of Symmetrical Diaryl Ketones with Formic Acid
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A convenient method for the palladium-catalyzed carbonylative homocoupling of aryl iodides was developed. With formic acid as the CO source, various symmetrical diaryl ketones were synthesized in moderate to good yield in the presence of a palladium catalyst.
- Wu, Fu-Peng,Peng, Jin-Bao,Qi, Xinxin,Wu, Xiao-Feng
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p. 173 - 177
(2017/11/27)
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- At normal pressure fragrant ketone copper catalytic synthesis method
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The invention discloses a method of synthesizing diaryl ketone under normal pressure by virtue of copper catalysis. The method is as follows: in a solvent alcohol or aqueous liquor of alcohol, under action of alkali and acid, adding a copper catalyst, alkyl iodide, alkyl boric acid and carbon monoxide to directly carry out crossed coupling reaction to prepare diaryl ketone compounds. According to the invention, the method of preparing diaryl ketone compounds by carbonylation Suzuki coupling reaction has the advantages as follows: the catalyst is wide in source, cheap and small in toxicity; the reaction is free of ligand in reaction and good in activity; the reaction is carried out under the normal pressure and selectivity is high; a substrate source is wide and stable; functional group compatibility is good and scope of application for the substrate is wide; a reaction medium is environment-friendly and recyclable. Under the condition of optimizing reaction conditions, the target product separating yield is 95%.
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Paragraph 0032; 0033; 0038
(2017/07/14)
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- Shifting Chemical Equilibria in Flow - Efficient Decarbonylation Driven by Annular Flow Regimes
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To efficiently drive chemical reactions, it is often necessary to influence an equilibrium by removing one or more components from the reaction space. Such manipulation is straightforward in open systems, for example, by distillation of a volatile product from the reaction mixture. Herein we describe a unique high-temperature/high-pressure gas/liquid continuous-flow process for the rhodium-catalyzed decarbonylation of aldehydes. The carbon monoxide released during the reaction is carried with a stream of an inert gas through the center of the tubing, whereas the liquid feed travels as an annular film along the wall of the channel. As a consequence, carbon monoxide is effectively vaporized from the liquid phase into the gas phase and stripped from the reaction mixture, thus driving the equilibrium to the product and preventing poisoning of the catalyst. This approach enables the catalytic decarbonylation of a variety of aldehydes with unprecedented efficiency with a standard coil-based flow device.
- Gutmann, Bernhard,Elsner, Petteri,Glasnov, Toma,Roberge, Dominique M.,Kappe, C. Oliver
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supporting information
p. 11557 - 11561
(2016/02/19)
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- SMALL MOLECULE LFA-1 INHIBITORS
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The present invention relates to novel compounds which are capable of inhibiting the interaction of LFA-1 with its counter ligands.
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Page/Page column 122
(2016/01/01)
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- Copper-catalyzed carbonylative Suzuki coupling of aryl iodides with arylboronic acids under ambient pressure of carbon monoxide
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An efficient and ligandless nanocopper-catalyzed carbonylative cross-coupling of aryl iodides with arylboronic acids at ambient CO pressure in poly(ethylene glycol), has been developed. This protocol is general, practical, and recyclable, and offers an attractive alternative to the corresponding palladium-mediated carbonylative Suzuki process for the construction of biaryl ketone scaffolds.
- Cheng, Laijin,Zhong, Yanzhen,Ni, Zhuchao,Du, Hongyan,Jin, Fengli,Rong, Qi,Han, Wei
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p. 44312 - 44316
(2014/12/10)
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- One-pot synthesis of diarylmethanones through palladium-catalyzed sequential coupling and aerobic oxidation of aryl bromides with acetophenone as a latent carbonyl donor
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A one-pot palladium-catalyzed synthesis of symmetrical and unsymmetrical diarylmethanones using acetophenone and aryl bromides as raw materials has been developed. In this reaction, acetophenone acts as a latent carbonyl donor and two pathways of palladium-catalyzed sequential coupling and aerobic oxidation are identified. The reaction is applicable to a spectrum of substrates and delivers the products in moderate to good yields. This method can be used for the synthesis of ketoprofen, a nonsteroidal anti-inflammatory drug, in a two-step procedure and 45% overall yield.
- Wang, Xing,Liu, Fu-Di,Tu, Hai-Yang,Zhang, Ai-Dong
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p. 6554 - 6562
(2014/08/05)
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- One-pot transformation of methylarenes into aromatic nitriles with inorganic metal-free reagents
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Various methylarenes were transformed into the corresponding aromatic nitriles in good to moderate yields by the treatment with aq. HBr and aq. H 2O2, followed by reaction with molecular iodine and aq. ammonia in a one-pot procedure. The present reaction is a useful, practical, transition-metal-free, and organic-reagent-free method for the preparation of aromatic nitriles from methylarenes. Various methylarenes were treated with aq. HBr and aq. H2O2 under warming conditions and/or irradiation conditions, followed by the reaction with molecular iodine and aq. ammonia, to provide the corresponding aromatic nitriles, in a one-pot procedure. The present reaction was carried out under metal-free and organic-reagent-free conditions. Copyright
- Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
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p. 4115 - 4122
(2014/07/08)
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- Palladium-catalyzed oxidative carbonylation for the synthesis of symmetrical diaryl ketones at atmospheric co pressure
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A mild and efficient synthesis of symmetrical diaryl ketones by palladium-catalyzed oxidative carbonylation of arylboronic acids with carbon monoxide at atmospheric pressure is reported. Georg Thieme Verlag Stuttgart New York.
- Li, Yang,Lu, Wei,Xue, Dong,Wang, Chao,Liu, Zhao-Tie,Xiao, Jianliang
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supporting information
p. 1097 - 1100
(2014/05/20)
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- Pd/Cu-cocatalyzed aerobic oxidative carbonylative homocoupling of arylboronic acids and CO: A highly selective approach to diaryl ketones
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A highly selective Pd/Cu-cocatalyzed aerobic oxidative carbonylative homocoupling of arylboronic acids has been developed. This method employs a simple catalytic system, readily available boronic acids as the substrates, molecular oxygen as the oxidant, and 1 atm of CO/O2, which makes this method practical for further applications.
- Ren, Long,Jiao, Ning
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supporting information
p. 2411 - 2414
(2014/10/15)
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- Rh-catalyzed carbonylation of arylzinc compounds yielding symmetrical diaryl ketones by the assistance of oxidizing agents
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Carbonylative homocoupling of arylzinc compounds 1 using 1 atm of CO and 1,2-dibromoethane as an oxidant was achieved in the presence of Rh-dppf catalyst, affording symmetrical diaryl ketones in good yields. Under similar conditions, Pd or Ni catalysts induced oxidative homocoupling of 1 to yield biaryls instead. The beneficial catalysis by Rh in the carbonylation was presumed to stem from the facility by which the migration of the aryl ligand to CO at the Rh3+ intermediate occurred.
- Kobayashi, Kana,Nishimura, Yugo,Gao, Fuxing,Gotoh, Kazuma,Nishihara, Yasushi,Takagi, Kentaro
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supporting information; experimental part
p. 1949 - 1952
(2011/06/20)
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- Convenient Processes for the Synthesis of Aromatic Ketones from Aryl Bromides and Carboxylic Anhydrides Using a Cobalt Catalysis
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The cross-coupling of various para- and meta-substituted aromatic bromides, mostly bearing sensitive moieties, with several carboxylic acid anhydrides is reported. This reaction can be carried out in two steps, by forming an aromatic organozinc reagent via cobalt catalysis in the first step, or even more interestingly in a single step, also by using a cobalt-based catalyst. The aromatic ketones are obtained by these new, mild, and convenient methods in 30-79% yields versus starting aryl bromide. Results are also disclosed that suggest the role played by cobalt species in the coupling of organozinc reagents with electrophiles could be similar to those of more commonplace transition metal complexes.
- Kazmierski, Igor,Bastienne, Mylene,Gosmini, Corinne,Paris, Jean-Marc,Perichon, Jacques
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p. 936 - 942
(2007/10/03)
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- Ultrafast Chemistry: Cobalt Carbonyl-Mediated Synthesis of Diaryl Ketones under Microwave Irradiation
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(Equation Presented) By combining the advantages of metal activation, in situ carbon monoxide delivery, and microwave heating, benzophenones were efficiently synthesized in 6-10 s. These ultrafast carbonylation reactions occur under air by flash heating o
- Enquist, Per-Anders,Nilsson, Peter,Larhed, Mats
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p. 4875 - 4878
(2007/10/03)
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- Synthesis and solubility properties of C60 fullerene derivatives bearing carboxy groups
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Bis(4-tert-butoxycarbonylphenyl)diazomethanes have been prepared and treated with fullerene (C60) to give the corresponding 1,2-methano derivatives which upon hydrolysis with CF3CO2H gave the title compounds. The solubility of the latter in aqueous THF has been measured.
- Tomioka, Hideo,Yamamoto, Katsutoshi
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- Heteroarylmethylbenzenes
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Compounds of formula I STR1 wherein Z is thiazolyl or isothiazolyl, and X, R, R0, R1, R2 and R3 are as defined in the description, have valuable pharmaceutical properties and are effective especially against tumors.
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- Tetrazolyl substituted benzonitriles and anti-tumor use thereof
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Compounds of formula I, STR1 wherein Tetr, R, R0, R1 and R2 are as defined in the description, have valuable pharmaceutical properties and are especially effective against tumors. They are prepared in a manner known per se
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- A NEW METHOD FOR THE PREPARATION OF SYMMETRICAL AROMATIC KETONES FROM AROMATIC CARBOXYLIC ACID
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Treatment of S-(2-pyridyl) aromatic thioates, readily derived from aromatic carboxylic acids, with bis(1,5-cyclooctadiene)nickel under mild conditions afforded symmetrical aromatic ketones in good yields.
- Goto, Toshio,Onaka, Makoto,Mukaiyama, Teruaki
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