- Rhodium(iii)-catalyzed asymmetric [4+1] spiroannulations of: O -pivaloyl oximes with α-diazo compounds
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Chiral RhIII catalysts can catalyze the asymmetric [4+1] spiroannulation of O-pivaloyl oximes with α-diazo homophthalimides under redox-neutral and acid/base-neutral conditions, leading to formation of chiral spirocyclic imines as a result of C-H activation and N-O cleavage. The reaction proceeded with high efficiency and features broad substrate scope, mild reaction conditions, and high to excellent enantioselectivities. This journal is
- Chang, Junbiao,Deng, Wei-Qiao,Kong, Lingheng,Li, Xingwei,Liu, Bingxian,Sun, Lincong,Wang, Fen,Zhao, Yanlian
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supporting information
p. 8268 - 8271
(2021/08/25)
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- AgNO3as Nitrogen Source for Cu-Catalyzed Cyclization of Oximes with Isocyanates: A Facile Route to N-2-Aryl-1,2,3-triazoles
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A versatile copper-catalyzed [3 + 1 + 1] annulation of oximes and isocyanates with AgNO3 is described. In this conversion, AgNO3 and isocyanates instead of conventional azide or diazonium reagents were used as the nitrogen source. This three-component transformation was achieved by cleaving N-O/C-H/C-N bonds and building CN/N-N bonds, which provides a strategy to prepare N-2-aryl-1,2,3-triazoles with a good substrate and functional compatibility.
- Liang, Jingwen,Rao, Yingqi,Zhu, Weidong,Wen, Tingting,Huang, Junjie,Chen, Zhichao,Chen, Lu,Li, Yibiao,Chen, Xiuwen,Zhu, Zhongzhi
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supporting information
p. 7028 - 7032
(2021/09/14)
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- Iron-Catalyzed, Iminyl Radical-Triggered Cascade 1,5-Hydrogen Atom Transfer/(5+2) or (5+1) Annulation: Oxime as a Five-Atom Assembling Unit
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By integration of iminyl radical-triggered 1,5-hydrogen atom transfer and (5+2) or (5+1) annulation processes, a series of structurally novel and interesting azepine and spiro-tetrahydropyridine derivatives have been successfully prepared in moderate to good yields. This method utilizes FeCl2 as the catalyst and readily available oximes as five-atom units, while showcasing broad substrate scope and good functional group compatibility. The annulation products can be easily converted into many valuable compounds. Moreover, DFT calculation studies are performed to provide some insights into the possible reaction mechanisms for the (5+2) and (5+1) annulations.
- Chen, Ying-Chun,Du, Fei,Jiang, Kun,Liang, Wu,Ouyang, Qin,Shuai, Li,Wei, Ye,Yang, Jie
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p. 19222 - 19228
(2020/08/25)
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- Synthesis of Functionalized Vinylsilanes via Metal-Free Dehydrogenative Silylation of Enamides
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A novel method of metal-free dehydrogenative silylation of enamides has been developed. The desired functionalized vinylsilane products were obtained in moderate to good yield and with high stereoselectivities. This protocol displays good tolerance of various functionalities. Furthermore, the high chemoselectivity of this reaction enables us to introduce different unsaturated C-C moieties to the products. The ease of further derivatization of the products to other useful compounds also demonstrates the highly synthetic utility of the current methodology.
- Chang, Xi-Hao,Wang, Zi-Lu,Zhao, Meng,Yang, Chao,Li, Jie-Jun,Ma, Wei-Wei,Xu, Yun-He
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supporting information
p. 1326 - 1330
(2020/02/13)
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- Direct Enamido C(sp2)?H Diphosphorylation Enabled by a PCET-Triggered Double Radical Relay: Access to gem-Bisphosphonates
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Herein we report a novel and straightforward protocol for the construction of valuable gem-BPs by means of proton-coupled electron-transfer (PCET)-triggered enamido C(sp2)?H diphosphorylation. This reaction represents a rare example of realizing the challenging double C?P bond formation at a single carbon atom, thus providing facile access to a broad variety of structurally diverse bisphosphonates from simple enamides under silver-mediated conditions. Initial mechanistic studies demonstrated that the diphosphorylation involves two rounds of PCET-initiated radical relay process.
- Cao, Hao-Qiang,Liu, Hao-Nan,Liu, Zhe-Yuan,Ma, Jun-An,Qiao, Bao-Kun,Zhang, Fa-Guang
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supporting information
p. 5515 - 5521
(2020/04/27)
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- Copper(0)/PPh3-Mediated Bisheteroannulations of o-Nitroalkynes with Methylketoximes Accessing Pyrazo-Fused Pseudoindoxyls
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A copper(0)/PPh3-mediated cascade bisheteroannulation reaction of o-nitroalkynes with methylketoximes has been developed that provides viable access to a diverse range of pyrazo-fused pseudoindoxyl compounds. Synthetically useful functional groups including sensitive C-I bonds are compatible with this system. Mechanistic studies suggest a reaction cascade involving sequential PPh3-mediated deoxygenative cycloisomerization and copper-catalyzed [3 + 2] pyrazo-annulation.
- Meng, Huanxin,Xu, Zhenhua,Qu, Zhonghua,Huang, Huawen,Deng, Guo-Jun
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supporting information
p. 6117 - 6121
(2020/08/12)
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- Merging alkenyl C-H activation with the ring-opening of 1,2-oxazetidines: Ruthenium-catalyzed aminomethylation of enamides
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1,2-Oxazetidines have been utilized as formaldimine precursors for the direct aminomethylation of enamides under a Ru(ii) species. By merging alkenyl C-H activation with ring-opening of 1,2-oxazetidines, this efficient protocol provides a facile and novel
- Hu, Lu-Min,Hu, Xu-Hong,Li, Song,Ma, Xue-Qing,Shan, Qi-Chao
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supporting information
p. 7969 - 7972
(2020/09/09)
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- Preparation method of pyrimidine salicylate oxime ester compound and application of compound as herbicide
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The invention discloses a preparation method of a pyrimidine salicylate oxime ester compound and application of the compound as a herbicide, belongs to the technical field of herbicides, and relates to the application of the herbicide in selectively controlling gramineous weeds and broadleaf weeds for crops. The compound is a pyrithiobac oxime ester compound. The preparation method includes the following steps that acids of pyrithiobac are condensed with substituted acetophenoxime in the presence of an organic solvent and a condensation agent to prepare a (I) compound. At 45 g a.i./hm, thecompound can effectively control echinochloa crusgalli, eleusineindica, setaria viridis, amaranthus retroflexus, portulaca oleracea, chenopodium album and other grassy weeds and broadleaf weeds, can serve as a candidate herbicide in a cotton field and has potential industrial application. Meanwhile, the compound is environmentally friendly, low in toxicity and highly safe for crops such as cotton.The invention provides a preparation technology of the efficient and safe novel pyrimidine salicylate oxime ester compound with the herbicidal activity, the compound can be massively produced, the yield is high and the purity is high.
- -
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Paragraph 0057; 0058
(2019/10/22)
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- Visible Light-Promoted Beckmann Rearrangements: Separating Sequential Photochemical and Thermal Phenomena in a Continuous Flow Reactor
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The Beckmann rearrangement of oximes to amides typically requires strong acids or highly reactive, hazardous electrophiles and/or elevated temperatures to proceed. A very attractive alternative is the in situ generation of Vilsmeier–Haack reagents, by means of photoredox catalysis, as promoters for the thermal Beckmann rearrangement. Investigation of the reaction parameters for this light-induced method using a one-pot strategy has shown that the reaction is limited by the different temperatures required for each of the two sequential steps. Using a continuous flow reactor, the photochemical and thermal processes have been separated by integrating a flow photoreactor unit at low temperature for the electrophile generation with a second reactor unit, at high temperature, where the rearrangement takes place. This strategy has enabled excellent conversions and yields for a diverse set of oximes, minimizing the formation of side products obtained with the original one-pot method.
- Chen, Yuesu,Cantillo, David,Kappe, C. Oliver
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supporting information
p. 2163 - 2171
(2019/03/14)
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- Direct access to bis-S-heterocycles via copper-catalyzed three component tandem cyclization using S8 as a sulfur source
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A novel strategy for constructing sulfur containing bis-S-heterocyclic compounds from oxime esters/vinyl azide, phenylacetylene/aldehydes and elemental sulfur (S8) has been developed. These transformations show good functional group tolerance. Various bis-S-heterocyclic products were efficiently synthesized from easily prepared or widely commercially available starting materials. In this protocol, S8 successfully served as a two-sulfur atom donor for thiophene and thiazole rings, respectively.
- Zhou, Peiqi,Huang, Yubing,Wu, Wanqing,Yu, Wentao,Li, Jianxiao,Zhu, Zhongzhi,Jiang, Huanfeng
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p. 3424 - 3432
(2019/04/01)
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- Access to 2-Aroylthienothiazoles via C-H/N-O Bond Functionalization of Oximes
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A novel strategy for the synthesis of 2-aroylthienothiazoles via C-H/N-O bond functionalization of ketoximes is developed. This reaction features excellent step- and atom-economy, as well as broad substrate scope. Various common ketoximes, even vinyl ketoximes, were efficiently converted to 2-aroylthienothiazoles. Preliminary mechanistic studies indicated that the radical process should be involved in this transformation. Moreover, the product exhibited good coordination with Cu(II), showing the potential application in the metal coordination field.
- Zhou, Peiqi,Huang, Yubing,Wu, Wanqing,Zhou, Jiaming,Yu, Wentao,Jiang, Huanfeng
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supporting information
p. 9976 - 9980
(2019/12/24)
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- Scope and mechanism of a true organocatalytic beckmann rearrangement with a boronic acid/perfluoropinacol system under ambient conditions
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Catalytic activation of hydroxyl functionalities is of great interest for the production of pharmaceuticals and commodity chemicals. Here, 2-alkoxycarbonyl- and 2-phenoxycarbonyl-phenylboronic acid were identified as efficient catalysts for the direct and chemoselective activation of oxime N-OH bonds in the Beckmann rearrangement. This classical organic reaction provides a unique approach to prepare functionalized amide products that may be difficult to access using traditional amide coupling between carboxylic acids and amines. Using only 5 mol % of boronic acid catalyst and perfluoropinacol as an additive in a polar solvent mixture, the operationally simple protocol features mild conditions, a broad substrate scope, and a high functional group tolerance. A wide variety of diaryl, aryl-alkyl, heteroaryl-alkyl, and dialkyl oximes react under ambient conditions to afford high yields of amide products. Free alcohols, amides, carboxyesters, and many other functionalities are compatible with the reaction conditions. Investigations of the catalytic cycle revealed a novel boron-induced oxime transesterification providing an acyl oxime intermediate involved in a fully catalytic nonself-propagating Beckmann rearrangement mechanism. The acyl oxime intermediate was prepared independently and was subjected to the reaction conditions. It was found to be self-sufficient; it reacts rapidly, unimolecularly without the need for free oxime. A series of control experiments and 18O labeling studies support a true catalytic pathway involving an ionic transition structure with an active and essential role for the boronyl moiety in both steps of transesterification and rearrangement. According to 11B NMR spectroscopic studies, the additive perfluoropinacol provides a transient, electrophilic boronic ester that is thought to serve as an internal Lewis acid to activate the ortho-carboxyester and accelerate the initial, rate-limiting step of transesterification between the precatalyst and the oxime substrate.
- Mo, Xiaobin,Morgan, Timothy D. R.,Ang, Hwee Ting,Hall, Dennis G.
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supporting information
p. 5264 - 5271
(2018/04/24)
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- Copper-catalyzed synthesis of thiazol-2-yl ethers from oxime acetates and xanthates under redox-neutral conditions
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A novel copper-catalyzed annulation of oxime acetates and xanthates for the synthesis of thiazol-2-yl ethers with remarkable regioselectivity has been developed. Various oxime acetates, whether derived from aryl ketones or alkyl ketones, or natural product cores are suitable for this conversion. Unique dihydrothiazoles were also obtained when both reaction sites were methine. Mechanistic studies indicated that imino copper(iii) intermediates were involved. In addition, this protocol proceeded under redox-neutral conditions and did not require additives or ligands.
- Zhu, Zhongzhi,Tang, Xiaodong,Cen, Jinghe,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 3767 - 3770
(2018/04/17)
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- Iminyl Radical-Mediated Controlled Hydroxyalkylation of Remote C(sp3)-H Bond via Tandem 1,5-HAT and Difunctionalization of Aryl Alkenes
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A visible-light mediated γ-hydroxyalkylation of ketones via C(sp3)-H functionalization has been developed under redox neutral conditions. This protocol relies on the iminyl radical-triggered 1,5-HAT followed by oxyalkylation of alkenes, wherein C?C and C?O bonds were constructed in one step. This three-component reaction features mild conditions, wide substrate scope and excellent functional group tolerance, thus providing a facile and highly efficient access to complex valuable ketones. (Figure presented.).
- Ma, Zhi-Yong,Guo, Li-Na,Gu, Yu-Rui,Chen, Li,Duan, Xin-Hua
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supporting information
p. 4341 - 4347
(2018/10/20)
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- Axial stereocontrol in: Tropos dibenz [c, e] azepines: The individual and cooperative effects of alkyl substituents
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6,7-Dihydro-5H-dibenz[c,e]azepines, a class of secondary amine incorporating a centre-axis chirality relay, can be prepared from N-(2-bromobenzyl)-N-(1-arylalkyl)methanesulfonamides via Pd-catalysed intramolecular direct arylation, and methylated at C(7)
- Balgobin, Sinead M. C.,Brookes, Dominic J.,Jiang, Junxiang,Pritchard, Robin G.,Wallace, Timothy W.
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supporting information
p. 10184 - 10199
(2017/12/26)
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- Synthesis of enaminones via copper-catalyzed decarboxylative coupling reaction under redox-neutral conditions
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A novel copper-catalyzed C(sp3)-H oxidative functionalization of aromatic oxime acetates with α-oxocarboxylic acids was reported. This process involved N-O/C-C bond cleavages and C-C bond formations to furnish substituted enaminones under redox-neutral conditions. The oxime acetates served as both reactants and internal oxidants. Furthermore, this transformation also features good functional group tolerance and needs no ligands or additional bases.
- Zhu, Zhongzhi,Tang, Xiaodong,Li, Jianxiao,Li, Xianwei,Wu, Wanqing,Deng, Guohua,Jiang, Huanfeng
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supporting information
p. 3228 - 3231
(2017/03/20)
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- Palladium-Catalyzed C-H Functionalization of Aromatic Oximes: A Strategy for the Synthesis of Isoquinolines
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An efficient strategy for synthesis of isoquinolines via Pd(II)-catalyzed cyclization reaction of oximes with vinyl azides or homocoupling of oximes is reported. Oximes could serve as a directing group and an internal oxidant in the transformation. This reaction features good functional group tolerance and provides a useful protocol for the synthesis of different kinds of isoquinolines under mild conditions. Some control experiments and 15N isotope labeling experiments were conducted for the mechanistic research. (Chemical Equation Presented).
- Zhu, Zhongzhi,Tang, Xiaodong,Li, Xianwei,Wu, Wanqing,Deng, Guohua,Jiang, Huanfeng
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p. 1401 - 1409
(2016/03/01)
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- Easy Access to 1-Amino and 1-Carbon Substituted Isoquinolines via Cobalt-Catalyzed C - H/N - O Bond Activation
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A green atom-economical method for the synthesis of highly functionalized 1-amino and 1-carbon substituted isoquinolines from the reaction of N′-hydroxybenzimidamides and aryl ketoximes, respectively, with alkynes via pentamethylcyclopentadienylcobalt(III)-catalyzed C - H/N - O bond activation is described. The external oxidant-free annulation reaction uses the =NOH moiety in N′-hydroxybenzimidamides or N-aromatic ketone oximes as the directing group and internal oxidant. This first row transition metal-catalyzed annulation serves as an efficient alternative for the synthesis of isoquinolines, as water is the only by-product and expensive noble metals such as rhodium(III), iridium(III), palladium(II), and ruthenium(II) are not required. The reaction proceeds via C - H activation, alkyne insertion, reductive elimination, and N - O activation.
- Muralirajan, Krishnamoorthy,Kuppusamy, Ramajayam,Prakash, Sekar,Cheng, Chien-Hong
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supporting information
p. 774 - 783
(2016/03/09)
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- TETRAZOLINONE COMPOUND AND USE THEREOF
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The compound represented by formula (1): wherein R4 and R5 each represents a hydrogen atom, a halogen atom, or a C1-C3 alkyl group; R6 represents a C1-C4 alkyl group, a C3-C6 cycloalkyl group, or the like; R7, R8, and R9 each represents a hydrogen atom, a halogen atom, or the like; R10 represents a C1-C3 alkyl group, or the like; R13 represents a C1-C3 alkyl group, or the like; and Q represents a phenyl group, or the like; has an excellent control effect on pests.
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Paragraph 0844-0845
(2015/11/16)
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- Self-catalyzed direct amidation of ketones: A sustainable procedure for acetaminophen synthesis
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High yielding amination of ketones and benzaldehyde in acid-less conditions has been conducted on several ketones to achieve amides and nitriles. The reactivity of the selected substrates showed to depend on both oximation and Beckmann rearrangement reaction rates. Oximation allows the in-situ production of hydrochloric acid that enables Beckmann rearrangement of the oxime to form the corresponding amide or nitrile. It is noteworthy that, using this one-pot synthetic approach, N-acetyl-4-aminophenol (acetaminophen drug), can be easily synthesized starting from 4-hydroxy-acetophenone in high yield. Acetanilide and ε-caprolactam can be also efficiently synthesized employing this synthetic procedure.
- Rancan, Elia,Aricò, Fabio,Quartarone, Giuseppe,Ronchin, Lucio,Tundo, Pietro,Vavasori, Andrea
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- Synthesis of isoquinolines via rhodium(III)-catalyzed dehydrative C-C and C-N coupling between oximines and alkynes
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Isoquinolines have been synthesized from the redox-neutral dehydrative C-N and C-C cross-coupling between oximines and alkynes using a catalytic amount of (pentamethylcyclopentadiene)rhodium dichloride dimer {[RhCp*Cl 2]2} and cesium
- Zhang, Xingping,Chen, Dan,Zhao, Miao,Zhao, Jing,Jia, Aiqun,Li, Xingwei
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supporting information; experimental part
p. 719 - 723
(2011/05/08)
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- Ruthenium-catalyzed hydrovinylation of N-acetylenamines leading to amines with a quaternary carbon center
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A catalytic hydrovinylation of N-acetylenamines with ethylene is reported. This new hydrovinylation reaction is catalyzed by a ruthenium hydride complex, RuHCl(CO)(PCy3)2, providing a series of N-acetylamines with a quaternary carbon center with up to 99% yield.
- Wang, Qiu-Shi,Xie, Jian-Hua,Li, Wei,Zhu, Shou-Fei,Wang, Li-Xin,Zhou, Qi-Lin
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supporting information; scheme or table
p. 3388 - 3391
(2011/08/21)
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- First iron-catalyzed synthesis of oximes from styrenes
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Aryl-substituted olefins react with t-butyl nitrite and sodium borohydride in the presence of iron(ii)phthalocyanine to give oximes in moderate to high yields.
- Prateeptongkum, Saisuree,Jovel, Irina,Jackstell, Ralf,Vogl, Nadine,Weckbecker, Christoph,Beller, Matthias
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supporting information; experimental part
p. 1990 - 1992
(2009/09/06)
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- Intermolecular Cope-type hydroamination of alkenes and alkynes using hydroxylamines
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The development of the Cope-type hydroamination as a method for the metal- and acid-free intermolecular hydroamination of hydroxylamines with alkenes and alkynes is described. Aqueous hydroxylamine reacts efficiently with alkynes in a Markovnikov fashion to give oximes and with strained alkenes to give N-alkylhydroxylamines, while unstrained alkenes are more challenging. N-Alkylhydroxy-lamines also display similar reactivity with strained alkenes and give modest to good yields with vinylarenes. Electron-rich vinylarenes lead to branched products while electron-deficient vinylarenes give linear products. A beneficial additive effect is observed with sodium cyanoborohydride, the extent of which is dependent on the structure of the hydroxylamine. The reaction conditions are found to be compatible with common protecting groups, free OH and NH bonds, as well as bromoarenes. Both experimental and theoretical results suggest the proton transfer step of the N-oxide intermediate is of vital importance in the intermolecular reactions of alkenes. Details are disclosed concerning optimization, reaction scope, limitations, and theoretical analysis by DFT, which includes a detailed molecular orbital description for the concerted hydroamination process and an exhaustive set of calculated potential energy surfaces for the reactions of various alkenes, alkynes, and hydroxylamines.
- Moran, Joseph,Gorelsky, Serge I.,Dimitrijevic, Elena,Lebrun, Marie-Eve,Bedard, Anne-Catherine,Seguin, Catherine,Beauchemin, Andre M.
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supporting information; experimental part
p. 17893 - 17906
(2009/07/18)
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- Aluminium chloride promoted carbohydroximoylation reaction of aromatic compounds with primary nitroalkanes
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The reaction of primary nitroalkanes with aromatic compounds in the presence of aluminium chloride afforded the corresponding carbohydroximoylated aromatic compounds.
- Kim,Song,Ryu
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p. 1711 - 1715
(2007/10/02)
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- Direct carbohydroximoylation of aromatics with primary nitroalkanes in triflic acid (TFSA)
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Primary nitroalkanes react with aromatics in triflic acid to yield arylated oximes at 70-80°C.
- Coustard, Jean-Marie,Jacquesy, Jean-Claude,Violeau, Bruno
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p. 8085 - 8086
(2007/10/02)
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- A High-Yield Regiospecific Synthesis of Keto Oximes from Aryl-Conjugated Ethylenes and Ethyl Nitrite in the Presence of Cobalt Complex and BH4- Ion
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The title reaction of substituted styrenes, 1-phenyl-1,3-butadiene, and some cyclic aryl-conjugated ethylenes proceeds smoothly at room temperature, affording the corresponding oximes in moderate to nearly quantitative yields.The reaction mechanism is discussed on the basis of the formation of an alkylcobalt intermediate and its subsequent reaction with ethyl nitrite.
- Okamoto, Tadashi,Kobayashi, Kenji,Oka, Shinzaburo,Tanimoto, Shigeo
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p. 4897 - 4901
(2007/10/02)
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- Cobalt-Catalyzed Reaction of Nitric Oxide with Aryl-Substituted Olefins in the Presence of Tetrahydroborate Ion
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A new transition-metal-catalyzed reaction of nitric oxide with aryl-substituted olefins in the presence of BH4- has been reported, where the oximes of alkyl aryl ketones are the products.The most successful results were obtained by using styrene and its ring-substituted derivatives as the substrate and Co(DH)2(py)Cl as the catalyst.A process involving the intermediate formation of a metal-alkyl complexes and its subsequent decomposition alkyl radical followed by the reaction of the radical with NO was proposed as the reaction mechanism in relation to the already reported cobalt-catalyzed oxygenation of aryl-substituted olefins.
- Okamoto, Tadashi,Kobayashi, Kenji,Oka, Shinzaburo,Tanimoto, Shigeo
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p. 5089 - 5092
(2007/10/02)
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