- Reconciling Electrostatic and n→π* Orbital Contributions in Carbonyl Interactions
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Interactions between carbonyl groups are prevalent in protein structures. Earlier investigations identified dominant electrostatic dipolar interactions, while others implicated lone pair n→π* orbital delocalisation. Here these observations are reconciled.
- Adam, Catherine,Borsley, Stefan,Cockroft, Scott L.,Ling, Kenneth B.,Mati, Ioulia K.,Muchowska, Kamila B.,Nichol, Gary S.,Pascoe, Dominic J.,Smolyar, Ivan V.
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Read Online
- Diversity-oriented synthesis of intensively blue emissive 3-hydroxyisoquinolines by sequential Ugi four-component reaction/reductive heck cyclization
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A convergent approach to highly functionalized 3-hydroxyisoquinolines is reported. The key steps are an Ugi multicomponent reaction and a subsequent intramolecular reductive Heck reaction; these can also be performed as a one-pot procedure. The structures
- Moni, Lisa,Valentini, Gianluca,Riva, Renata,Deniβen, Melanie,Müller, Thomas J. J.
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Read Online
- Transient imine as a directing group for the metal-free o-C-H borylation of benzaldehydes
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Organoboron reagents are important synthetic intermediates and have wide applications in synthetic organic chemistry. The selective borylation strategies that are currently in use largely rely on the use of transition-metal catalysts. Hence, identifying much milder conditions for transition-metal-free borylation would be highly desirable. We herein present a unified strategy for the selective C-H borylation of electron-deficient benzaldehyde derivatives using a simple metal-free approach, utilizing an imine transient directing group. The strategy covers a wide spectrum of reactions and (i) even highly sterically hindered C-H bonds can be borylated smoothly, (ii) despite the presence of other potential directing groups, the reaction selectively occurs at the o-C-H bond of the benzaldehyde moiety, and (iii) natural products appended to benzaldehyde derivatives can also give the appropriate borylated products. Moreover, the efficacy of the protocol was confirmed by the fact that the reaction proceeds even in the presence of a series of external impurities.
- Rej, Supriya,Chatani, Naoto
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p. 2920 - 2929
(2021/03/01)
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- V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
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The versatile application of different functional groups such as alcohols (1° and 2°), alkyl arenes, and (aryl)olefins to construct carbon-oxygen bond via oxidation is an area of intense research. Here, we report a reusable heterogeneous V2O5@TiO2 catalyzed selective oxidation of various functionalities utilizing different mild and eco-compatible oxidants under greener reaction conditions. The method was successfully applied for the alcohol oxidation, oxidative scission of styrenes, and benzylic C?H oxidation to their corresponding aldehydes and ketones. The utilization of mild and eco-friendly oxidizing reagents such as K2S2O8, H2O2 (30 % aq.), TBHP (70 % aq.), broad substrate scope, gram-scale synthesis, and catalyst recyclability are notable features of the developed protocol.
- Upadhyay, Rahul,Kumar, Shashi,Maurya, Sushil K.
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p. 3594 - 3600
(2021/07/02)
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- Sulfur-Based Chiral Iodoarenes: An Underexplored Class of Chiral Hypervalent Iodine Reagents
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Chiral hypervalent iodine reagents are active players in modern stereoselective organic synthesis. Structurally diverse chiral hypervalent iodine reagents have been synthesised and extensively studied, but hypervalent iodine reagents containing chiral sul
- Alharbi, Haifa,Elsherbini, Mohamed,Karam, Fatemah,Osi, Arnaud,Wirth, Thomas
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- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
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A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method includes the steps of: (A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst; wherein, the catalyst is represented by Formula (II): M(O)mL1yL2z??(II);wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and(B) mixing the compound with an unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):
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Paragraph 0071; 0077
(2021/07/10)
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- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
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A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method comprises the following step: (A) providing a compound (I) with an unsaturated double bond, a reagent with trifluoromethyl, and a catalyst; wherein the catalyst is represented by the following formula (II): M(O)mL1yL2z (II); wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and (B) mixing the compound with an unsaturated double bond and the reagent with a trifluoromethyl to perform an oxidation of the compound with the unsaturated double bond by using the catalyst at air or an oxygen condition to get a compound presented as formula (III):
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Paragraph 0053-0054; 0062-0063
(2021/03/19)
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- Iodolopyrazolium Salts: Synthesis, Derivatizations, and Applications
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The synthesis of iodolopyrazolium triflates via an oxidative cyclization of 3-(2-iodophenyl)-1H-pyrazoles is described. The reaction is characterized by a broad substrate scope, and various applications of these novel cyclic iodolium salts acting as useful synthetic intermediates are demonstrated, in particular in site-selective ring openings. This was finally applied to generate derivatives of the anti-inflammatory drug celecoxib. Their application as highly active halogen-bond donors is shown as well.
- Boelke, Andreas,Caspers, Lucien D.,Kuczmera, Thomas J.,Lork, Enno,Nachtsheim, Boris J.
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supporting information
p. 7261 - 7266
(2020/10/05)
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- One-Pot Synthesis and Conformational Analysis of Six-Membered Cyclic Iodonium Salts
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Two one-pot procedures for the construction of carbon-bridged diaryliodonium triflates and tetrafluoroborates are described. Strong Br?nsted acids enable the effective Friedel-Crafts alkylation with diversely substituted o-iodobenzyl alcohol derivatives, providing diphenylmethane scaffolds, which are subsequently oxidized and cyclized to the corresponding dibenzo[b,e]iodininium salts. Based on NMR investigations and density functional theory (DFT) calculations, we could verify the so-far-undescribed existence of two stable isomers in cyclic iodonium salts substituted with aliphatic side chains in the carbon bridge.
- Caspers, Lucien D.,Spils, Julian,Damrath, Mattis,Lork, Enno,Nachtsheim, Boris J.
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p. 9161 - 9178
(2020/08/14)
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- KMnO4-catalyzed chemoselective deprotection of acetate and controllable deacetylation-oxidation in one pot
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A novel and efficient protocol for chemoselective deacetylation under ambient conditions was developed using catalytic KMnO4. The stoichiometric use of KMnO4 highlighted the dual role of a heterogeneous oxidant enabling direct access to aromatic aldehydes in one-pot sequential deacetylation-oxidation. The reaction employed an alternative solvent system and allowed the clean transformation of benzyl acetate to sensitive aldehyde in a single step while preventing over-oxidation to acids. Use of inexpensive and readily accessible KMnO4 as an environmentally benign reagent and the ease of the reaction operation were particularly attractive, and enabled the controlled oxidation and facile cleavage of acetate in a preceding step. This journal is
- Gurawa, Aakanksha,Kumar, Manoj,Rao, Dodla S.,Kashyap, Sudhir
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supporting information
p. 16702 - 16707
(2020/10/27)
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- A Simple, Mild and General Oxidation of Alcohols to Aldehydes or Ketones by SO2F2/K2CO3 Using DMSO as Solvent and Oxidant
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A practical, general and mild oxidation of primary and secondary alcohols to carbonyl compounds proceeds in yields of up to 99% using SO2F2 as electrophile in DMSO as both the oxidant and the solvent at ambient temperature. No moisture- and oxygen-free conditions are required. Stoichiometric amount of inexpensive K2CO3, which generates easy to separate by-products, is used as the base. Thus, 5-gram scale runs proceeded in nearly quantitative yields by a simple filtration as the work-up. The use of a polar solvent such as DMSO, which usually promotes competing Pummerer rearrangement, is also noteworthy. This protocol is compatible with a variety of common N-, O-, and S-functional groups on (hetero)arene, alkene and alkyne substrates (68 examples). The protocol was applied (99% yield) to a formal synthesis of the important cholesterol-lowering drug Rosuvastatin. (Figure presented.).
- Zha, Gao-Feng,Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
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supporting information
p. 2262 - 2267
(2019/04/17)
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- One-pot synthesis of hypervalent diaryl(iodo)bismuthanes from o-carbonyl iodoarenes by zincation
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Diaryl(iodo)bismuthanes possessing a hypervalent C=O???Bi-I bond were conveniently synthesized in a one-pot reaction by using arylzinc reagents generated from o-carbonyl iodobenzenes and zinc powder under ultrasonication. This method is superior to the conventional organolithium and Grignard methods because it has a wide functional group tolerance, requires no protecting group manipulations, and proceeds under mild reaction conditions that do not need low temperature control. Furthermore, no intermediate triarylbismuthane precursor for the hypervalent iodobismuthane is necessary.
- Murafuji, Toshihiro,Hafizur Rahman,Magarifuchi, Daiki,Narita, Masahiro,Miyakawa, Isamu,Ishiguro, Katsuya,Kamijo, Shin
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- Chemoselective Reduction of Sterically Demanding N,N-Diisopropylamides to Aldehydes
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A sequential one-pot process for chemoselectively reducing sterically demanding N,N-diisopropylamides to aldehydes has been developed. In this reaction, amides are activated with EtOTf to form imidates, which are reduced with LiAlH(OR)3 [R = t-Bu, Et] to give aldehydes by hydrolysis of the resulting hemiaminals. The non-nucleophilic base 2,6-DTBMP remarkably improves reaction efficiency. The combination of EtOTf/2,6-DTBMP and LiAlH(O-t-Bu)3 was found to be optimal for reducing alkyl, alkenyl, alkynyl, and 2-monosubstituted aryl N,N-diisopropylamides. In contrast, EtOTf and LiAlH(OEt)3 in the absence of base were found to be optimal for reducing extremely sterically demanding 2,6-disubstituted N,N-diisopropylbenzamides. The reaction tolerates various reducible functional groups, including aldehyde and ketone. 1H NMR studies confirmed the formation of imidates stable in water. The synthetic usefulness of this methodology was demonstrated with N,N-diisopropylamide-directed ortho-metalation and C-H bond activation.
- Xiao, Peihong,Tang, Zhixing,Wang, Kai,Chen, Hua,Guo, Qianyou,Chu, Yang,Gao, Lu,Song, Zhenlei
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p. 1687 - 1700
(2018/02/23)
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- N-Heterocycle-Stabilized Iodanes: From Structure to Reactivity
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Pseudocyclic aryl-λ3-iodanes are superior reagents for a variety of oxidative transformations due to a well-balanced relation between stability, solubility and reactivity. Their properties are substantially influenced by a dative interaction between a Lewis base, in general the oxygen atom of a carboxylic acid or an amide, and the central hypervalent iodine atom. This work presents the first systematic investigation of pseudocyclic N-heterocycle-stabilized iodanes (NHIs). The synthesis of these throughout shelf-stable solids is robust and can be achieved on a large scale. Their reactivity is highly tunable, depending on the stabilizing heterocycle. Solid state structures of selected derivatives are reported and their reactivity in a model oxygen transfer reaction is compared. Further derivatization reactions to N-heterocycle-stabilized pseudocyclic diaryliodonium salts and cyclic iodoso species are presented as well.
- Boelke, Andreas,Lork, Enno,Nachtsheim, Boris J.
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supporting information
p. 18653 - 18657
(2018/11/23)
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- Palladium-Catalyzed, Norbornene-Mediated, ortho-Amination ipso-Amidation: Sequential C-N Bond Formation
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A palladium-catalyzed, norbornene-mediated ortho- and ipso-C-N bond-forming Catellani reaction is reported. This reaction proceeds through a sequential intermolecular amination followed by intramolecular cyclization of a tethered amide. The products, ortho-aminated dihydroquinolinones, were generated in moderate to good yields and are present in bioactive molecules. This work highlights the challenge of competing intra- vs intermolecular palladium-catalyzed processes.
- Whyte, Andrew,Olson, Maxwell E.,Lautens, Mark
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supporting information
p. 345 - 348
(2018/01/27)
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- NH3?H2O: The Simplest Nitrogen-Containing Ligand for Selective Aerobic Alcohol Oxidation to Aldehydes or Nitriles in Neat Water
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Aqueous ammonia (NH3?H2O) has been shown to serve as the simplest nitrogen-containing ligand to effectively promote copper-catalyzed selective alcohol oxidation under air in water. A series of alcohols with varying electronic and steric properties were selectively oxidized to aldehydes with up to 95 % yield. Notably, by increasing the amount of aqueous ammonia in neat water, the exclusive formation of aryl nitriles was also accomplished with good-to-excellent yields. Additionally, the catalytic system exhibits a high level of functional group tolerance with ?OH, ?NO2, esters, and heteroaryl groups all being amenable to the reaction conditions. This one-pot and green oxidation protocol provides an important synthetic route for the selective preparation of either aldehydes or nitriles from commercially available alcohols.
- Zhang, Guofu,Ma, Danting,Zhao, Yiyong,Zhang, Guihua,Mei, Guangyao,Lyu, Jinghui,Ding, Chengrong,Shan, Shang
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p. 885 - 889
(2018/12/10)
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- Radical Alkyne peri-Annulation Reactions for the Synthesis of Functionalized Phenalenes, Benzanthrenes, and Olympicene
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Radical cyclization reactions at a peri position were used for the synthesis of polyaromatic compounds. Depending on the choice of reaction conditions and substrate, this flexible approach led to Bu3Sn-substituted phenalene, benzanthrene, and olympicene derivatives. Subsequent reactions with electrophiles provided synthetic access to previously inaccessible functionalized polyaromatic compounds.
- Tsvetkov, Nikolay P.,Gonzalez-Rodriguez, Edgar,Hughes, Audrey,dos Passos Gomes, Gabriel,White, Frankie D.,Kuriakose, Febin,Alabugin, Igor V.
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supporting information
p. 3651 - 3655
(2018/03/06)
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- Synthetic Studies Toward the Skyllamycins: Total Synthesis and Generation of Simplified Analogues
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Herein, we report our synthetic studies toward the skyllamycins, a highly modified class of nonribosomal peptide natural products which contain a number of interesting structural features, including the extremely rare α-OH-glycine residue. Before embarking on the synthesis of the natural products, we prepared four structurally simpler analogues. Access to both the analogues and the natural products first required the synthesis of a number of nonproteinogenic amino acids, including three β-OH amino acids that were accessed from the convenient chiral precursor Garner's aldehyde. Following the preparation of the suitably protected nonproteinogenic amino acids, the skyllamycin analogues were assembled using a solid-phase synthetic route followed by a final stage solution-phase cyclization reaction. To access the natural products (skyllamycins A-C) the synthetic route used for the analogues was modified. Specifically, linear peptide precursors containing a C-terminal amide were synthesized via solid-phase peptide synthesis. After cleavage from the resin the N-terminal serine residue was oxidatively cleaved to a glyoxyamide moiety. The target natural products, skyllamycins A-C, were successfully prepared via a final step cyclization with concomitant formation of the unusual α-OH-glycine residue. Purification and spectroscopic comparison to the authentic isolated material confirmed the identity of the synthetic natural products.
- Giltrap, Andrew M.,Haeckl, F. P. Jake,Kurita, Kenji L.,Linington, Roger G.,Payne, Richard J.
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p. 7250 - 7270
(2018/06/01)
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- Imprinted Naked Pt Nanoparticles on N-Doped Carbon Supports: A Synergistic Effect between Catalyst and Support
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A synergistic effect resulting from the interaction of small (2.4–3.1 nm) naked Pt nanoparticles (NPs) imprinted on N-doped carbon supports is evidenced by structural, electronic and electrochemical characterization. The size and distribution of the sputtered Pt NPs are found to be related to the nature of the support because Pt NPs are preferentially located at Ngraphitic sites. In addition, Rutherford backscattering shows that a deeper penetration of the Pt NPs is obtained in the N-doped carbon support with larger pore diameters. The ligand effect of the N-doped carbon supports is found to occur by electron donation from Npyrrolic and Ngraphitic sites to the Pt NPs and the electron acceptor behavior of the C=Npyridinic sites. The carbon matrix acquires a basic characteristic (electron-richer, metallic behavior) capable of interacting with metallic NPs akin to a bimetallic-like system. The imprinted Pt NPs are active catalysts for oxidation, although displaying poor catalytic activity for reduction reactions. The catalyst N-doped carbon supports play an important role in the overall catalytic process, rather than only acting as a simple active phase carrier.
- Bolzan, Gustavo R.,Abarca, Gabriel,Gon?alves, Wellington D. G.,Matos, Carolina F.,Santos, Marcos J. L.,Dupont, Jairton
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supporting information
p. 1365 - 1372
(2017/12/26)
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- Cu(I)-Catalyzed Coupling and Cycloisomerization of Diazo Compounds with Terminal Yne-Alkylidenecyclopropanes: Synthesis of Functionalized Cyclopenta[ b]naphthalene Derivatives
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A Cu(I)-catalyzed coupling and cycloisomerization of diazo compounds with terminal yne-alkylidenecyclopropanes (ACPs) has been presented. This reaction starts from the formation of an allenic intermediate in the Cu(I)-catalyzed cross-coupling reaction of a diazo compound with terminal alkyne in yne-tethered ACP and then undergoes a domino cycloisomerization of a 6π-electrocyclization and cyclopropane ring-opening rearrangement to give functionalized cyclopenta[b]naphthalene derivatives in moderate to excellent yields under mild conditions.
- Li, Peng-Hua,Yu, Liu-Zhu,Zhang, Xiao-Yu,Shi, Min
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p. 4516 - 4520
(2018/08/09)
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- Weinreb Amide Directed Versatile C?H Bond Functionalization under (η5-Pentamethylcyclopentadienyl)cobalt(III) Catalysis
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The (η5-pentamethylcyclopentadienyl)cobalt(III) (Cp*CoIII)-catalyzed C?H bond functionalization of aromatic, heteroaromatic, and α,β-unsaturated Weinreb amides was explored. C?H allylation reactions with the use of allyl carbonate and a perfluoroalkene, oxidative alkenylation reactions with the use of ethyl acrylate, iodination reactions with the use of N-iodosuccinimide, and amidation reactions with the use of dioxazolones were catalyzed by Cp*Co(CO)I2 in the presence of a cationic Ag salt and AgOAc to afford various synthetically useful building blocks. Mechanistic studies of the C?H allylation disclosed that the C?H activation step was rate determining and virtually irreversible.
- Kawai, Kentaro,Bunno, Youka,Yoshino, Tatsuhiko,Matsunaga, Shigeki
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supporting information
p. 10231 - 10237
(2018/07/29)
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- A bis(pyridyl)-: N -alkylamine/Cu(i) catalyst system for aerobic alcohol oxidation
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Herein a bis(pyridyl)-N-alkylamine/CuI/TEMPO/NMI catalyst system is reported for aerobic oxidation of a variety of primary alcohols to the corresponding aldehydes using readily available reagents, at room temperature and ambient air as the oxidant. ESI-MS analysis of the reaction showed the formation of a [(L1)(NMI)CuII-OOH]+ species, which is a key intermediate in the alcohol oxidation reaction. Evaluation of the effect of reaction parameters on the initial rate of the reaction allowed us to obtain the optimum conditions for catalytic activity. The careful choice of reaction solvent allowed for the oxidation of 4-hydroxybenzyl alcohol, a substrate which proved problematic in previous studies. In the case of 2-pyridinemethanol as substrate, experimental evidence shows that catalytic activity is diminished due to competitive inhibition of the catalyst by the alcohol substrate.
- Marais, Lindie,Burés, Jordi,Jordaan, Johan H. L.,Mapolie, Selwyn,Swarts, Andrew J.
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p. 6926 - 6933
(2017/09/01)
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- Amine-based compound and organic light-emitting diode including the same
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An amine-based compound is represented by Formula 1: An organic light-emitting diode includes a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode. The organic layer includes an emission layer an
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Page/Page column 91; 93
(2017/07/08)
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- Method for preparing aldehyde by oxidizing primary alcohol
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The invention discloses a method for preparing aldehyde by catalytic oxidation of primary alcohol. The method comprises the steps that the primary alcohol as shown in a formula (I) or (III) is taken as a raw material, copper salt is taken as a catalyst, air is taken as an oxidizing agent, TEMPO (2,2,6,6-tetramethyl-1-piperidine-N-oxyl compound) is taken as a pro-oxygenic agent, ammonium hydroxide is taken as a co-catalyst and solvent, the primary alcohol, the copper salt, the air, the TEMPO and the ammonium hydroxide are mixed uniformly and react for 9 to 24 hours at the temperature of 60 to 120 DEG C; after the reaction, reaction liquid is subjected to aftertreatment to obtain aldehyde as shown in a formula (II) or (IV). The method has the advantages of high reaction rate and yield, low cost, convenience in operation and safety in reaction. The whole process is environmental friendly and free of pollution.
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Paragraph 0026; 0027; 0028; 0029; 0030; 0056; 0057-0060
(2017/07/21)
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- Pd-Catalyzed Selective Synthesis of Cyclic Sulfonamides and Sulfinamides Using K2S2O5 as a Sulfur Dioxide Surrogate
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A variety of cyclic sulfonamides and sulfinamides could be selectively synthesized under Pd catalysis using haloarenes bearing amino groups and a sulfur dioxide (SO2) surrogate. The amount of base was key in determining the selectivity. Mechanistic studies revealed that sulfinamides were initially formed via an unprecedented formal insertion of sulfur monoxide and were oxidized to sulfonamides in the presence of an iodide ion and DMSO.
- Konishi, Hideyuki,Tanaka, Hiromichi,Manabe, Kei
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supporting information
p. 1578 - 1581
(2017/04/13)
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- Total Synthesis of Skyllamycins A–C
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The skyllamycins are a family of highly functionalized non-ribosomal cyclic depsipeptide natural products which contain the extremely rare α-OH-glycine functionality. Herein the first total synthesis of skyllamycins A–C is reported, together with the biofilm inhibitory activity of the natural products. Linear peptide precursors for each natural product were prepared through an efficient solid-phase route incorporating a number of synthetic modified amino acids. A novel macrocyclization step between a C-terminal amide and an N-terminal glyoxylamide moiety served as a key transformation to install the unique α-OH-glycine unit and generate the natural products in the final step of the synthesis.
- Giltrap, Andrew M.,Haeckl, F. P. Jake,Kurita, Kenji L.,Linington, Roger G.,Payne, Richard J.
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supporting information
p. 15046 - 15049
(2017/10/31)
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- Base Catalysis Enables Access to α,α-Difluoroalkylthioethers
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A nucleophilic addition reaction of aryl thiols to readily available β,β-difluorostyrenes provides α,α-difluoroalkylthioethers. The reaction proceeds through an unstable anionic intermediate, prone to eliminate fluoride and generate α-fluorovinylthioethers. However, the use of base catalysis overcomes the facile β-fluoride elimination, generating α,α-difluoroalkylthioethers in excellent yields and selectivities.
- Orsi, Douglas L.,Easley, Brandon J.,Lick, Ashley M.,Altman, Ryan A.
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supporting information
p. 1570 - 1573
(2017/04/13)
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- Overcoming chloroquine resistance in malaria: Design, synthesis and structure-activity relationships of novel chemoreversal agents
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Malaria remains a significant infectious disease with even artemisinin-based therapies now facing resistance in the field. Development of new therapies is urgently needed, either by finding new compounds with unique modes of action, or by reversing resistance towards known drugs with 'chemosensitizers' or 'chemoreversal' agents (CRA). Concerning the latter, we have focused on the resistance mechanisms developed against chloroquine (CQ). We have synthesized a series of compounds related to previously identified CRAs, and found promising novel compounds. These compounds show encouraging results in a coumarin labeled chloroquine uptake assay, exhibiting a dose response in resensitising parasites to the antimalarial effects of chloroquine. Selected compounds show consistent potency across a panel of chloroquine and artemisinin sensitive and resistant parasites, and a wide therapeutic window. This data supports further study of CRAs in the treatment of malaria and, ultimately, their use in chloroquine-based combination therapies.
- Boudhar, Aicha,Ng, Xiao Wei,Loh, Chiew Yee,Chia, Wan Ni,Tan, Zhi Ming,Nosten, Francois,Dymock, Brian W.,Tan, Kevin S.W.
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p. 231 - 249
(2016/05/24)
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- Intramolecular Pd-Catalyzed Arylation of 1-Amidosugars: A New Route to N-Glycosyl Quinolin-2-ones
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The synthesis of N-glycosylated quinolin-2-ones via an intramolecular N-arylation of glycosylamides is reported. The coupling involves the use of only Pd(OAc)2 as the catalyst and nBu4NOAc as the base in 1,4-dioxane. This versatile approach allows the synthesis of various N-glycosylated quinolin-2-ones with exclusive α or β selectivity.
- Luong, Thi Thanh Huyen,Brion, Jean-Daniel,Lescop, Ewen,Alami, Mouad,Messaoudi, Samir
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supporting information
p. 2126 - 2129
(2016/06/01)
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- Compound and organic light emitting device comprising same
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Disclosed are a compound represented by chemical formula 1 and an organic light-emitting device comprising the same. The explanation with respect to a substituent in chemical formula 1 refers to the detailed description. The organic light-emitting device
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Paragraph 0387; 0395-0401
(2016/10/07)
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- Method for preparing aldehyde/ketone by catalyzing alcohol oxidation with ferric salt
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The invention provides a method for preparing aldehyde/ketone by catalyzing alcohol oxidation with a ferric salt. The method comprises the following steps: mixing a compound shown in a formula (I) of a substrate, a ferric salt catalyst, a cocatalyst TEMPO (tetramethylpiperidinooxy), an amino acid ligand and a solvent; carrying out return flow agitation in an oxygen or air atmosphere for 1 to 60 h; then post-processing a reaction solution to obtain a product, namely a compound shown in a formula (II). According to the method provided by the invention, the ferric acid which is low in cost, easily available and environment-friendly is used as the catalyst; amino acids which are rich in resource, low in cost, easily available and easy to modify in a natural field are used as the ligand; the reaction substrate is high in applicability; first-grade benzyl alcohol, second-grade benzyl alcohol, allyl alcohol, heterocyclic aromatic alcohols and the like can be converted into corresponding aldehyde/ketone at high yield by adopting an oxidation system of the invention.
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Paragraph 0038; 0039; 0040; 0057; 0058; 0059; 0060
(2016/10/07)
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- Copper-mediated aerobic iodination and perfluoroalkylation of boronic acids with (CF3)2CFI at room temperature
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The copper-mediated aerobic reactions between the branched (CF3)2CFI and boronic acids (R-B(OH)2) are described. Different from the linear perfluoroalkyl analogs CF3(CF2)nI (n?=?2, 3, 5, 7), (CF3)2CFI reacting with R-B(OH)2at room temperature under air in the presence of catalytic Cu powder provided exclusively the corresponding iodides (R-I), while the aerobic reactions of arylboronic acids with (CF3)2CFI at room temperature in the presence of Cu(OAc)2gave the perfluoroalkylation products (R-CF(CF3)2) in acceptable to moderate yields. The iodination reaction could be further promoted by hydroquinone, the addition of which improved the oxidation ability of (CF3)2CFI and provided the ipso-iodination products in high yields. The perfluoroalkylation was facilitated by the copper carboxylates since the addition of these salts into the reaction mixtures could successfully give rise to Ar-CF(CF3)2.
- Liu, Xi-Hai,Leng, Jing,Jia, Su-Jiao,Hao, Jian-Hong,Zhang, Fanglin,Qin, Hua-Li,Zhang, Cheng-Pan
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- Zinc(II)-Assisted Aryl Finkelstein Reaction for the Synthesis of Aryl Iodides
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Aryl iodides play an important role in synthetic organic chemistry as they are frequently utilized in cross-coupling reactions and in oxidation processes using hypervalent iodine compounds. Their synthesis is, however, often cumbersome and may lead to unwanted side products. Here, we report on an improved protocol for the aryl Finkelstein reaction in which dehalogenation is prevented by addition of zinc iodide in lieu of copper(I). Generally, electron-poor ortho-bromo methyl benzoates, amides, and even unprotected phenols are well-suited for this method.
- Ueberschaar, Nico,Heine, Daniel,Hertweck, Christan
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p. 1794 - 1797
(2016/07/16)
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- Highly practical oxidation of benzylic alcohol in continuous-flow system with metal-free catalyst
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Oxidation of benzylic alcohol to ketone or aldehyde is one of the most challenging reactions in terms of green chemistry. We report herein that employing H2O2, catalytic amount of Br- and acid in continuous-flow system to realize oxidation of benzylic alcohols with broad substrate scope and high selectivity. More importantly, no over oxidation to acid was obtained and it showed higher selectivity to 2° hydroxyl groups rather than 1°.
- Liu, Chengkou,Fang, Zheng,Yang, Zhao,Li, Qingwen,Guo, Shiyu,Zhang, Kai,Ouyang, Pingkai,Guo, Kai
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p. 5973 - 5976
(2015/10/28)
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- Process Development of CuI/ABNO/NMI-Catalyzed Aerobic Alcohol Oxidation
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An improved Cu/nitroxyl catalyst system for aerobic alcohol oxidation has been developed for the oxidation of functionalized primary and secondary alcohols to aldehydes and ketones, suitable for implementation in batch and flow processes. This catalyst, which has been demonstrated in a >50 g scale batch reaction, addresses a number of process limitations associated with a previously reported (MeObpy)CuI/ABNO/NMI catalyst system (MeObpy = 4,4′-dimethoxy-2,2′-bipyridine, ABNO = 9-azabicyclo[3.3.1]nonane N-oxyl, NMI = N-methylimidazole). Important catalyst modifications include the replacement of [Cu(MeCN)4]OTf with a lower-cost Cu source, CuI, reduction of the ABNO loading to 0.05-0.3 mol%, and use of NMI as the only ligand/additive (i.e., without a need for MeObpy). Use of a high flash point solvent, N-methylpyrrolidone, enables safe operation in batch reactions with air as the oxidant. For continuous-flow applications compatible with elevated gas pressures, better performance is observed with acetonitrile as the solvent.
- Steves, Janelle E.,Preger, Yuliya,Martinelli, Joseph R.,Welch, Christopher J.,Root, Thatcher W.,Hawkins, Joel M.,Stahl, Shannon S.
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p. 1548 - 1553
(2015/12/01)
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- Highly practical sodium(i)/azobenzene catalyst system for aerobic oxidation of benzylic alcohols
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An economic, environmental and practical aerobic oxidation of benzylic alcohols and hetero aryl alcohols to the corresponding carbonyl compounds with good substrate scope is disclosed for the first time. Good to excellent yields were obtained by employing economic and commercially available sodium bromide and a catalytic amount of azobenzene under metal-free and ligand-free conditions. Moreover, aldehydes and acids, the oxidation products of benzylic 1° alcohols, could be obtained using sodium bromide and sodium hydroxide as the co-catalyst respectively in high yields.
- Liu, Chengkou,Fang, Zheng,Yang, Zhao,Li, Qingwen,Guo, Shiyu,Guo, Kai
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p. 79699 - 79702
(2015/10/06)
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- Pinpoint-fluorinated phenacenes: New synthesis and solubility enhancement strategies
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The Pd(II)-catalyzed cyclizations of 2,2-difluorovinylated biaryls, following a Friedel-Crafts-type mechanism, provide a new route to pinpoint-fluorinated phenacenes. The single fluorine substituent stabilized the synthesized fluoropicenes (fluoro[5]phenacenes) toward aerial oxidation and contributed to their solubility in organic solvents. For example, 6- and 13-fluoropicenes were 25- and 15-fold more soluble in THF than nonfluorinated picene. X-ray crystal structure analysis revealed that the fluorine substituent did not alter molecular planarity.
- Fuchibe, Kohei,Morikawa, Toshiyuki,Shigeno, Kento,Fujita, Takeshi,Ichikawa, Junji
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supporting information
p. 1126 - 1129
(2015/03/14)
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- Pinpoint-fluorinated phenanthrene synthesis based on C-F bond activation of difluoroalkenes Dedicated to Prof. Véronique Gouverneur on the occasion of her receipt of the 2014 ACS Award for Creative Work in Fluorine Chemistry.
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Treatment with a cationic palladium(II) catalyst promoted the Friedel-Crafts-type cyclization of 1,1-difluoro-1-alkenes bearing a biphenyl skeleton to afford regioselectively fluorinated (pinpoint-fluorinated) phenanthrenes via C-F bond activation. The obtained pinpoint-fluorinated phenanthrenes were observed to be organized by π-π and C-H?F interactions to exhibit columnar and layer structures in the solid state.
- Fuchibe, Kohei,Morikawa, Toshiyuki,Ueda, Ryu,Okauchi, Tatsuo,Ichikawa, Junji
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supporting information
p. 106 - 115
(2015/11/10)
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- SULFAMATE DERIVATIVE COMPOUND FOR USE IN PREVENTING OR TREATING EPILEPSY
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The present invention relates to a pharmaceutical composition for treating or preventing epilepsy containing a sulfamate derivative compound and/or pharmaceutically acceptable salt thereof as an active ingredient. Furthermore, the present invention relates to a method for treatment or prevention epilepsy comprising administering a sulfamate derivative compound in a pharmaceutically effective amount to a subject in need of treatment or prevention of epilepsy.
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Page/Page column 21
(2015/06/25)
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- Photocatalytic oxidation of benzyl alcohols by three-dimensional reduced graphene oxide/nano zinc oxide catalyst under visible light
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A three-dimensional reduced graphene oxide/nano zinc oxide (3D-RGO/ZnO) composite photocatalyst has been prepared through an in situ reduction of GO and growth of nano ZnO particles process. The 3D-RGO/ZnO catalyst displayed enhanced photocatalytic activity towards commercial ZnO nanoparticles and can be applied to the oxidation of a broad series of benzyl alcohols including primary and secondary alcohols to corresponding carbonyl compounds under the irradiation of visible light. A plausible photocatalytic mechanism referring to photo electron generation and transfer has been proposed.
- Wang, Yuxiang,Zhang, Xianlong,Wang, Lihua,Chen, Youjian
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p. 727 - 730
(2016/01/26)
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- Light-sensitive and recoverable n-heterocyclic carbene copper(I) complex in homogeneous catalysis
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The synthesis of a light-responsive N-heterocyclic carbene copper(I) complex by introducing a nitrobenzospiropyran unit into the carbene ligand was developed. The solubility of this complex was controlled through reversible conversion between its netural and ionic states using ultraviolet light irradiation. Taking advantage of such a light-sensitive property facilitated its recovery and reuse in copper(I)-catalyzed homogeneous oxidation and "click" reactions.
- Zhang, Guodong,Lang, Rui,Wang, Wenlong,Lv, Hui,Zhao, Liyuan,Xia, Chungu,Li, Fuwei
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supporting information
p. 917 - 922
(2015/03/30)
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- Selective Oxidation of Benzyl Alcohols to Aldehydes with a Salophen Copper(II) Complex and tert-Butyl Hydroperoxide at Room Temperature
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(Figure Presented) An efficient and selective oxidation of benzyl alcohols has been developed using a salophen copper(II) complex as the catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant in the presence of base. Moderate to excellent yields of the corresponding benzaldehydes were obtained at room temperature without the carboxylic acids being formed.
- Chen, Tingting,Cai, Chun
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supporting information
p. 1334 - 1341
(2015/05/27)
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- Mild oxidation of alcohols with o-iodoxybenzoic acid in liquid tetrabutylammonium bromide
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A mild, green and low cost method for o-iodoxybenzoic acid mediated oxidation of alcohols to carbonyl compounds has been established. In this protocol, liquid tetrabutylammonium bromide was used as the solvent and the primary alcohols were selectively oxidized to aldehyde and secondary alcohols were easily transformed to ketones.
- Liu, Yangyang,Xie, Aming,Cao, Meiping,Feng, Liandong,Wang, Boliang
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p. 587 - 590
(2015/01/30)
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- Fluorous bispidine: A bifunctional reagent for copper-catalyzed oxidation and knoevenagel condensation reactions in water
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Fluorous bispidine-type ligands have been developed to facilitate its recovery and reusability and to demonstrate its bifunctional property as a ligand and base in copper-catalyzed aerobic oxidation, the Knoevenagel condensation and tandem oxidation/Knoevenagel condensation in water under mild conditions. Application of the fluorous ligand was also extended to the surfactant-free copper-catalyzed allylic and benzylic sp3 C-H oxidation reaction in water. The fluorous ligands could be recovered using F-SPE with recovery ranging from 91-97% and could be reused five times with little loss of activity.
- Ang, Wei Jie,Chng, Yong Sheng,Lam, Yulin
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p. 81415 - 81428
(2015/10/06)
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- Lewis Acid Catalyzed Formal Intramolecular [3 + 3] Cross-Cycloaddition of Cyclopropane 1,1-Diesters for Construction of Benzobicyclo[2.2.2]octane Skeletons
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A novel Lewis acid catalyzed formal intramolecular [3 + 3] cross-cycloaddition (IMCC) of cyclopropane 1,1-diesters has been successfully developed. This supplies an efficient and conceptually new strategy for construction of bridged bicyclo[2.2.2]octane skeletons. This [3 + 3]IMCC could be run up to gram scale and from easily prepared starting materials. This [3 + 3]IMCC, together with our previously reported [3 + 2]IMCC strategy, can afford either the bicyclo[2.2.2]octane or bicyclo[3.2.1]octane skeletons from the similar starting materials by regulating the substituents on vinyl group.
- Ma, Weiwei,Fang, Jie,Ren, Jun,Wang, Zhongwen
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supporting information
p. 4180 - 4183
(2015/09/15)
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- Reductive arene ortho-silanolization of aromatic esters with hydridosilyl acetals
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This work describes the design and application of a single-pot, reductive arene C-H silanolization of aromatic esters for synthesis of ortho-formyl arylsilanols. This strategy involves a sequence of two transition metal (Ir and Rh)-catalyzed reactions for reductive arene ortho-silylation directed by hydridosilyl acetals and hydrolysis.
- Hua, Yuanda,Asgari, Parham,Dakarapu, Udaya Sree,Jeon, Junha
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supporting information
p. 3778 - 3781
(2015/03/30)
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- Zn(II)- or Ag(I)-catalyzed 1,4-metathesis reactions between 3-en-1-ynamides and nitrosoarenes
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Catalyst-dependent metathesis reactions between 3-en-1-ynamides and nitrosoarenes are described. Particularly notable are the unprecedented 1,4-metathesis reactions catalyzed by Ag(I) or Zn(II) to give 2-propynimidamides and benzaldehyde derivatives. With 3-en-1-ynamides bearing a cycloalkenyl group, 1,4-oxoimination products were produced efficiently. We have developed metathesis/alkynation cascades for unsubstituted 2-propynimidamides and benzaldehyde species generated in situ, to manifest 1,4-hydroxyimination reactions of 3-en-1-ynes. Both 1,4-oxoiminations and 1,4-hydroxyiminations increase the molecular complexity of products.
- Gawade, Sagar Ashok,Huple, Deepak B.,Liu, Rai-Shung
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p. 2978 - 2981
(2014/03/21)
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- Synthesis, structure, and catalytic activity of new ruthenium(II) indenylidene complexes bearing unsymmetrical N - heterocyclic carbenes
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New robust and air-stable ruthenium(II) indenylidene type second-generation precatalysts with unsymmetrical N-heterocyclic carbene (NHC) ligands were synthesized. The reaction profiles of these complexes were studied in commercial-grade solvents in air with model substrates leading to the di-, tri-, and tetrasubstituted olefins. In addition, application of selected precatalysts for olefin metathesis reactions on a broad spectrum of substrates with different functional groups was examined. Studies of solvent effects for the selected precatalysts as well as thermal activation of the corresponding complexes showed significant differences in their activities. Observed relationships in connection with single-crystal X-ray analysis revealed the influence of the unsymmetrical NHC ligands on the initiation rate of precatalysts. Dissociation of the phosphine ligand, the rate-determining step for our most active precatalysts, is accelerated by the steric repulsion of the dangling benzyl arm and the tricyclohexylphosphine ligand. A precatalyst with a hemilabile benzyl arm evinced decreased activity, probably due to coordination of the heteroatom to the ruthenium core taking place after dissociation of the phosphine ligand.
- Ablialimov, Osman,Kedziorek, Mariusz,Malinska, Maura,Wozniak, Krzysztof,Grela, Karol
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supporting information
p. 2160 - 2171
(2014/06/09)
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- Practical organic solvent-free Cu(OAc)2/DMAP/TEMPO-catalyzed aldehyde and imine formation from alcohols under air atmosphere
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A highly efficient and practical organic solvent-free Cu(OAc)2/DMAP/TEMPO catalyst system for the selective aerobic oxidation of benzylic and allylic alcohols to aldehydes and phenones under an ambient air atmosphere was reported. A wide range of functional groups such as phenolic hydroxyl, amino, and methylthio are compatible with the catalyst system. The organic solvent-free aerobic oxidative imine synthesis from benzyl alcohol and amines was also achieved via the newly developed Cu(OAc)2/DMAP/TEMPO catalyst. 100 g-scale reactions for aldehyde and imine formation were achieved with over 90% yield using 0.5 mol% catalyst loading in 36 hours, presenting a potential valuable protocol for both economical and environmental considerations. This journal is
- Guan, Mingyu,Wang, Chao,Zhang, Jingyu,Zhao, Yingsheng
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p. 48777 - 48782
(2014/12/10)
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- PHENYL CARBAMATE COMPOUNDS FOR USE IN PREVENTING OR TREATING PEDIATRIC EPILESY AND EPILESY-RELATED SYNDROMES
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The present invention provides a pharmaceutical composition for preventing and/or treating a pediatric epilepsy or epilepsy-related syndrome comprising the phenyl carbamate compound as an active ingredient, and a use of the phenyl carbamate compound for p
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Page/Page column 46
(2014/09/29)
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