- Beckmann rearrangement of ketoximes promoted by cyanuric chloride and dimethyl sulfoxide under a mild condition
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Synthesis of amides via Beckmann rearrangement of ketoximes promoted by cyanuric chloride (TCT)/DMSO under mild conditions has been reported. Conditions of the Beckmann rearrangement, e.g., solvents, the ratios of TCT/DMSO, and the temperature, were investigated using diphenylmethanone oxime as a substrate. The optimized conditions were adopted to afford fourteen amides with yields ranging from 20% to 99%. A plausible mechanism involving an active dimethyl alkoxysulfonium intermediate was proposed according to the mass spectrometry analysis. To our best knowledge, this is the first case of study on Beckmann rearrangement of ketoximes promoted by TCT/DMSO under a mild condition to afford amides efficiently.
- Ma, Ruonan,Chen, Xueyuan,Xiao, Zhiyin,Natarajan, Mookan,Lu, Chunxin,Jiang, Xiujuan,Zhong, Wei,Liu, Xiaoming
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supporting information
(2021/01/06)
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- Chlorotropylium Promoted Conversions of Oximes to Amides and Nitriles
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Chlorotropylium chloride as a catalyst for the transformations of oximes, ketones, and aldehydes to their corresponding amides and nitriles in excellent yields (up to 99 %) and in short reaction times (mostly 10–15 min). Oximes were electrophilically attacked on the hydroxyl oxygen by chlorotropylium. The produced tropylium oxime ethers were the key intermediates, of which the ketoxime ether led to amide through Beckmann rearrangement, and the aldoxime ether led to nitrile by nitrogen base DBU assisted formal dehydration. This chlorotropylium activation protocol offered general, mild, and efficient avenues bifurcately from oximes to both amides and nitriles by one organocatalyst.
- Xu, Jiaxi,Gao, Yu,Li, Zhenjiang,Liu, Jingjing,Guo, Tianfo,Zhang, Lei,Wang, Haixin,Zhang, Zhihao,Guo, Kai
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p. 311 - 315
(2020/01/25)
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- Access to Cyanoimines Enabled by Dual Photoredox/Copper-Catalyzed Cyanation of O-Acyl Oximes
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An efficient strategy for the synthesis of pharmaceutically important and synthetically useful cyanoimines, as well as cyanamides, has been described. This strategy is enabled by dual photoredox/copper-catalyzed cyanation of O-acyl oximes or O-acyl hydroxamides. This state of the art protocol for cyanoimines and cyanamides features readily available starting materials, mild reaction conditions, good functional group tolerance, and operational simplicity. The resultant cyanoimines can be transformed into structurally diverse and functionally important N-containing heterocycles.
- Wei, Ziyan,Yu, Shouyun,Zhang, Ai Hua,Zhang, Hao
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supporting information
p. 7315 - 7320
(2020/10/02)
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- Microdroplets as Microreactors for Fast Synthesis of Ketoximes and Amides
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The formation of amide bonds is one of the most valuable transformations in organic synthesis. Beckmann rearrangement is a well-known method for producing secondary amides from ketoximes. This study demonstrates the rapid synthesis of ketoximes and amides in microdroplets. Many factors are found to affect the yield, such as microdroplet generation devices, temperature, catalysts, and concentrations of reactants. In particular, the temperature has a great influence on the synthesis of amide, which is demonstrated by a sharp ascendance to the yield when the temperature was increased to 45 °C. The best amide yield (93.3%) can be obtained by using coaxial flowing devices, a sulfonyl chloride compound as a catalyst, and heating to 55 °C in microdroplets. The yields can reach 78.7-91.3% for benzoylaniline and 87.2-93.4% for benzophenone oximes in several seconds in microdroplets compared to 10.1-66.1% and 82.5-93.3% in several hours in the bulk phase. Apart from the dramatically decreased reaction time and enhanced reaction yields, the microdroplet synthesis is also free of severe reaction environments (anhydrous and anaerobic conditions). In addition, the synthesis in microdroplets also saves reactants and solvents and reduces the waste amounts. All of these merits indicate that the microdroplet synthesis is a high-efficiency green methodology.
- Zhang, Wenwen,Yang, Shiwei,Lin, Qiuyu,Cheng, Heyong,Liu, Jinhua
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p. 851 - 859
(2019/01/24)
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- o-Phthalic Anhydride/Zn(OTf)2 co-catalyzed Beckmann rearrangement under mild conditions
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o-Phthalic anhydride/Zn(OTf)2 co-catalyzed Beckmann rearrangement was developed, producing the corresponding amide in up to 99% yield with acid-sensitive functionalities tolerated well, and the scale of the reaction could be enlarged to 77 mmol and the excellent yield was maintained. A successive procedure was developed. Moreover, the reaction was carried out at rt under nearly neutral conditions, and the workup was concise. These features illustrated the potential of the protocol in amide synthesis.
- Xu, Ze-Feng,Zhang, Teng,Hong, Wenjun
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supporting information
p. 3113 - 3117
(2019/05/08)
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- Pt-catalyzed O-silylation of oximes by tri-substituted organosilanes
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Silylated derivatives of oximes are important intermediates in organic synthesis, and have found application in the preparation of various nitrogen containing compounds including nitriles, amines, nitrones, and hydroxylamines. An efficient method for the
- Bhatt, Shreeja V.,Bhatt, Shreya V.,Fotie, Jean
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supporting information
p. 1636 - 1639
(2019/06/04)
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- Beckmann rearrangement of ketoxime catalyzed by N-methyl-imidazolium hydrosulfate
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Beckmann rearrangement of ketoxime catalyzed by acidic ionic liquid-N-methyl-imidazolium hydrosulfate was studied. Rearrangement of benzophenone oxime gave the desirable product with 45% yield at 90 ?C. When co-catalyst P2O5 was added, the yield could be improved to 91%. The catalyst could be reused three cycles with the same efficiency. Finally, reactions of other ketoximes were also investigated.
- Hu, Hongyu,Cai, Xuting,Xu, Zhuying,Yan, Xiaoyang,Zhao, Shengxian
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- Dichloroimidazolidinedione-Activated Beckmann Rearrangement of Ketoximes for Accessing Amides and Lactams
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A novel protocol for the activation of the Beckmann rearrangement utilizing the readily available and economical geminal dichloroimidazolidinediones (DCIDs) on a substoichiometric scale (10 mol %) has been developed. A unique self-propagating mechanism for the substoichiometric dichloroimidazolidinedione-activated transformation was proposed and validated. The substrate scope of the developed protocol has been demonstrated by 23 examples with good to excellent yields (mostly 90-98%) in a short time (mostly 10-30 min), including a substrate for synthesizing the monomer of nylon-12 and a complicated steroidal substrate on a preparative scale. This research not only unveils for the first time the synthetic potential of substoichiometric amounts of dichloroimidazolidinediones in promoting chemical transformation but also offers yet another important illustration of the self-propagating cycle in the context of the Beckmann rearrangement activated by a structurally novel organic promoter.
- Gao, Yu,Liu, Jingjing,Li, Zhenjiang,Guo, Tianfo,Xu, Songquan,Zhu, Hui,Wei, Fulan,Chen, Siming,Gebru, Hailemariam,Guo, Kai
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p. 2040 - 2049
(2018/02/23)
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- Preparation method of ketoxime
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The invention belongs to the technical field of ketoxime and specifically relates to a preparation method of ketoxime. The preparation method comprises the following steps: (1) sufficiently mixing ketone and hydroxylamine hydrochloride, adding absolute ethyl alcohol, and stirring till total dissolution to obtain mixed liquid 1; (2) adding imidazolyl anion functionalized ionic liquid into the mixedliquid 1, and heating till ethanol reflux, wherein reaction liquid is obtained after the reaction; (3) removing ethanol in the reaction liquid, adding deionized water and stirring to separate out solid, and performing suction filtration and washing to obtain white solid ketoxime. According to the preparation method provided by the invention, by taking the imidazolyl anion functionalized ionic liquid as a catalyst, a reaction between ketone and hydroxylamine hydrochloride can be efficiently catalyzed, and the preparation method has the advantages of mild reaction conditions, high product yieldand purity and the like.
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Paragraph 0038-0040
(2018/07/30)
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- Asymmetric Nitrone Synthesis via Ligand-Enabled Copper-Catalyzed Cope-Type Hydroamination of Cyclopropene with Oxime
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We report realization of the first enantioselective Cope-type hydroamination of oximes for asymmetric nitrone synthesis. The ligand promoted asymmetric cyclopropene "hydronitronylation" process employs a Cu-based catalytic system and readily available starting materials, operates under mild conditions and displays broad scope and exceptionally high enantio- and diastereocontrol. Preliminary mechanistic studies corroborate a CuI-catalytic profile featuring an olefin metalla-retro-Cope aminocupration process as the key C-N bond forming event. This conceptually novel reactivity enables the first example of highly enantioselective catalytic nitrone formation process and will likely spur further developments that may significantly expedite chiral nitrone synthesis.
- Li, Zhanyu,Zhao, Jinbo,Sun, Baozhen,Zhou, Tingting,Liu, Mingzhu,Liu, Shuang,Zhang, Mengru,Zhang, Qian
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supporting information
p. 11702 - 11705
(2017/09/07)
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- Discovery of N-[Bis(4-methoxyphenyl)methyl]-4-hydroxy-2-(pyridazin-3-yl)pyrimidine-5-carboxamide (MK-8617), an Orally Active Pan-Inhibitor of Hypoxia-Inducible Factor Prolyl Hydroxylase 1-3 (HIF PHD1-3) for the Treatment of Anemia
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The discovery of novel 4-hydroxy-2-(heterocyclic)pyrimidine-5-carboxamide inhibitors of hypoxia-inducible factor (HIF) prolyl hydroxylases (PHD) is described. These are potent, selective, orally bioavailable across several species, and active in stimulati
- Debenham, John S.,Madsen-Duggan, Christina,Clements, Matthew J.,Walsh, Thomas F.,Kuethe, Jeffrey T.,Reibarkh, Mikhail,Salowe, Scott P.,Sonatore, Lisa M.,Hajdu, Richard,Milligan, James A.,Visco, Denise M.,Zhou, Dan,Lingham, Russell B.,Stickens, Dominique,Demartino, Julie A.,Tong, Xinchun,Wolff, Michael,Pang, Jianmei,Miller, Randy R.,Sherer, Edward C.,Hale, Jeffrey J.
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p. 11039 - 11049
(2016/12/30)
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- Lewis acid-assisted N-fluorobenzenesulfonimide-based electrophilic fluorine catalysis in Beckmann rearrangement
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A microwave-assisted N-fluorobenzenesulfonimide (NFSI)/Lewis acid-catalyzed Beckmann rearrangement was developed. The remarkable promotion to the electrophilicity of NFSI by Lewis acids was illustrated utilizing a series of readily available oxime substrates. The action model between NFSI and Lewis acids was probed by control experiments and theoretical calculations.
- Xie, Fukai,Du, Chuan,Pang, Yadong,Lian, Xu,Xue, Chentao,Chen, Yanyu,Wang, Xuefei,Cheng, Maosheng,Guo, Chun,Lin, Bin,Liu, Yongxiang
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supporting information
p. 5820 - 5824
(2016/12/06)
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- Organic Compounds
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A compound of formula (I) or stereoisomers or pharmaceutically acceptable salts thereof, and their preparation and use as pharmaceuticals wherein R1, R2 and R3 are as defined herein.
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Page/Page column 73
(2010/12/29)
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- PURINE DERIVATIVES AS A2A RECEPTOR AGONISTS
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A compound of formula (I) or stereoisomers or pharmaceutically acceptable salts thereof.and their preparation and use as A2A receptor agonists
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Page/Page column 37
(2008/06/13)
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- ORGANIC COMPOUNDS
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A compound of formula (I) or stereoisomers or pharmaceutically acceptable salts thereof, and their preparation and use as pharmaceuticals wherein Rl, R2 and R3 are as defined herein.
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Page/Page column 47
(2008/06/13)
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- PURINE DERIVATIVES ACTING AS A2A RECEPTOR AGONISTS
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Compounds of formula (I) in free or salt form, wherein R1, R2 and R3 have the meanings as indicated in the specification, are useful for treating conditions mediated by activation of the adenosine A2A receptor, especially inflammatory or obstructive airways diseases. Pharmaceutical compositions that contain the compounds and a process for preparing the compounds are also described.
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Page/Page column 36
(2008/06/13)
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- PURINE DERIVATIVES FOR USE AS ADENOSIN A-2A RECEPTOR AGONISTS
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Compounds of formula (I) in free or salt form, wherein R1, R2 and R3 have the meanings as indicated in the specification, are useful for treating conditions mediated by activation of the adenosine A2A receptor,
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Page/Page column 46-47
(2010/11/08)
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- Aminolysis of O-(2,4-dinitrophenyl)-p-p′-disubstituted benzophenone oximes in benzene: Evidence for Hirst's mechanism
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The reactions of O-(2,4-dinitropnenyl)-substituted p,p′-dimethoxybenzophenone oxime, p,p′-fluorobenzophenone oxime and p,p×-dichlorobenzophenone oxime with pyrrolidine and piperidine in benzene were found to be third order in amine, with no uncatalytic ro
- Jain, Ajay K.,Singh, Prashant,Sahoo
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p. 770 - 776
(2007/10/03)
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- Asymmetric 1,3-Dipolar Cycloaddition: Synthesis of N-protected (4S)-4-Hydroxy L-Glutamic Acid Diester
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An asymmetric synthesis of N-protected (4S)-4-hydroxy L-glutamic acid diester is described.The key feature of the synthesis is the asymmetric 1,3-dipolar cycloaddition of nitrone 4 with 5, which provides stereoselectively the isoxazolidine with the correc
- Gefflaut, Thierry,Bauer, Udo,Airola, Karri,Koskinen, Ari M. P.
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p. 3099 - 3102
(2007/10/03)
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- The catalytic Friedel-Crafts acylation reaction and the catalytic Beckmann rearrangement promoted by a Gallium(III) or an antimony(V) cationic species
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The catalytic Friedel-Crafts acylation reaction and the catalytic Beckmann rearrangement are successfully carried out by using the active cationic species dichlorogallium(III) perchlorate and tetrachloroantimonium(V) hexafluoroantimonate(V), respectively, which were generated in situ from appropriate silver, gallium(III) or antimony(V) salts.
- Harada,Ohno,Kobayashi,Mukaiyama
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p. 1216 - 1220
(2007/10/02)
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- Diphenyl-methane compounds useful in the treatment of diseases caused by aggregation of platelets or formation of thrombus
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A new diphenyl-methane derivative is useful to inhibit agglomeration of blood and is defined by the formula, including a diphenylethylene derivative and a benzophenone oxime ether derivative. STR1 in which R1 and R2 each are hydrogen, hydroxyl or a lower alkoxy, U is =CXY or =N--O--W, X is hydrogen, cyano or --COR6, R6 being hydroxyl or an amino, Y is --R10--COOR3, R3 being hydrogen or a lower alkoxy, R10 being an alkylene having 1 to 3 carbon atoms, straight or branched, --CO--NR4R5, R4 and R5 each being hydrogen, a lower alkyl or a lower arylalkyl, --CH2--NHSO2--C6H5 or --C(R8)=NR7, R7 being a lower alkoxy or an aryl, R8 is --VR9, V being oxygen, sulfur or nitrogen, R9 being an alkyl or an aryl, W is --CH2--CO--CH2--COOR13, R13 being hydrogen or a lower alkyl, --CH2--C(C=NOR14)--CH2--COOR15, R15 being hydrogen or a lower alkyl, R14 being a lower alkyl, --CH(CN)--(CH2)q--COOR16, R16 being hydrogen or a lower alkyl, q being an integer of 1 to 3, or --(CH2)p--Z, Z being --SH, --SCN or a monovalent group derived from a five- or six-membered ring which may be substituted by a ring having one or more sulfur atoms in the ring, p being 1 or 2.
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- ARYL SUBSTITUENT EFFECTS UPON THE THERMAL ISOMERIZATION OF N-ALKYL OXAZIRIDINES TO NITRONES
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The results of a kinetic study of the thermal isomerization of oxaziridines derived from para-substituted C-arylaldimines and C-diarylketimines to the isomeric nitrones is reported.
- Boyd, Derek R.,Coulter, Peter B.,Hamilton, W. James,Jennings, W. Brian,Wilson, Valerie E.
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p. 2287 - 2288
(2007/10/02)
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