- Iron-Catalyzed C-C Single-Bond Cleavage of Alcohols
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An iron-catalyzed deconstruction/hydrogenation reaction of alcohols through C-C bond cleavage is developed through photocatalysis, to produce ketones or aldehydes as the products. Tertiary, secondary, and primary alcohols bearing a wide range of substituents are suitable substrates. Complex natural alcohols can also perform the transformation selectively. A investigation of the mechanism reveals a procedure that involves chlorine radical improved O-H homolysis, with the assistance of 2,4,6-collidine.
- Liu, Wei,Wu, Qiang,Wang, Miao,Huang, Yahao,Hu, Peng
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supporting information
p. 8413 - 8418
(2021/11/01)
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- Nickel-Mediated Photoreductive Cross Coupling of Carboxylic Acid Derivatives for Ketone Synthesis**
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A simple visible light photochemical, nickel-catalyzed synthesis of ketones from carboxylic acid-derived precursors is presented. Hantzsch ester (HE) functions as a cheap, green and strong photoreductant to facilitate radical generation and also engages in the Ni-catalytic cycle to restore the reactive species. With this dual role, HE allows for the coupling of a large variety of radicals (1°,2°, benzylic, α-oxy & α-amino) with aroyl and alkanoyl moieties, a new feature in reactions of this type. With both precursors deriving from abundant carboxylic acids, this protocol is a welcome addition to the organic chemistry toolbox. The reaction proceeds under mild conditions without the need for toxic metal reagents or bases and shows a wide scope, including pharmaceuticals and complex molecular architectures.
- Brauer, Jan,Quraishi, Elisabeth,Kammer, Lisa Marie,Opatz, Till
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supporting information
p. 18168 - 18174
(2021/11/30)
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- PROCESS FOR THE PREPARATION OF ALKOXYLATES COMPOSITIONS
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A mixture of two alkoxylates surfactants, one being an aryl aliphatic carbinol alkoxylate, the other one being a dialiphatic carbinol alkoxylate, said mixture being useful for stabilizing emulsions and dispersions used in agricultural or pharmaceutical formulations. The alkoxylates surfactants may serve as substitutes for nonylphenol ethoxylates (NPE) and tristyrylphenol ethoxylates (TSE).
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Page/Page column 23
(2019/06/17)
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- Controlling the selectivity and efficiency of the hydrogen borrowing reaction by switching between rhodium and iridium catalysts
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The catalytic alkylation of ketones with alcohols via the hydrogen borrowing methodology (HB) has the potential to be a highly efficient approach for forming new carbon-carbon bonds. However, this transformation can result in more than one product being formed. The work reported here utilises bidentate triazole-carbene ligated iridium and rhodium complexes as catalysts for the selective formation of alkylated ketone or alcohol products. Switching from an iridium centre to a rhodium centre in the complex resulted in significant changes in product selectivity. Other factors-base, base loading, solvent and reaction temperature-were also investigated to tune the selectivity further. The optimised conditions were used to demonstrate the scope of the reaction across 17 ketones and 14 alcohols containing a variety of functional groups. A series of mechanistic investigations were performed to probe the reasons behind the product selectivity, including kinetic and deuterium studies.
- Wang, Danfeng,McBurney, Roy T.,Pernik, Indrek,Messerle, Barbara A.
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supporting information
p. 13989 - 13999
(2019/10/01)
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- Nickel-Catalyzed Alkylation of Ketone Enolates: Synthesis of Monoselective Linear Ketones
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Herein we have developed a Ni-catalyzed protocol for the synthesis of linear ketones. Aryl, alkyl, and heteroaryl ketones as well as alcohols yielded the monoselective ketones in up to 90% yield. The catalytic protocol was successfully applied in to a gram-scale synthesis. For a practical utility, applications of a steroid derivative, oleyl alcohol, and naproxen alcohol were employed. Preliminary catalytic investigations involving the isolation of a Ni intermediate and defined Ni-H species as well as a series of deuterium-labeling experiments were performed.
- Das, Jagadish,Vellakkaran, Mari,Banerjee, Debasis
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p. 769 - 779
(2019/01/24)
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- PROCESS FOR THE CATALYTIC DECARBOXYLATIVE CROSS-KETONIZATION OF ARYL AND ALIPHATIC CARBOXYLIC ACID
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The present invention pertains to a process for the cross-ketonization (Piria reaction) between an aryl carboxylic acid and an aliphatic carboxylic acid using a metal-based compound and a slight or a moderate excess of aryl carboxylic acid. A good selectivity, up to 99 mol %, can be achieved. The aryl aliphatic ketone can be used for the preparation of surfactants and other downstream products.
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Page/Page column 66; 67; 69
(2019/01/08)
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- NiH-Catalyzed Reductive Relay Hydroalkylation: A Strategy for the Remote C(sp3)?H Alkylation of Alkenes
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The terminal-selective, remote C(sp3)?H alkylation of alkenes was achieved by a relay process combining NiH-catalyzed hydrometalation, chain walking, and alkylation. This method enables the construction of unfunctionalized C(sp3)?C(sp3) bonds under mild conditions from two simple feedstock chemicals, namely olefins and alkyl halides. The practical value of this transformation is further demonstrated by the large-scale and regioconvergent alkylation of isomeric mixtures of olefins at low catalyst loadings.
- Zhou, Fang,Zhu, Jin,Zhang, Yao,Zhu, Shaolin
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supporting information
p. 4058 - 4062
(2018/03/21)
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- Method for synthesizing aromatic aldehyde, aromatic ketone and aromatic ester through catalytically oxidizing alkyl aromatic compound by iron
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The invention discloses a method for synthesizing aromatic aldehyde, aromatic ketone and aromatic ester through catalytically oxidizing an alkyl aromatic compound by iron, and belongs to the technical field of catalytic synthesis. According to the method, a low-cost and environment-friendly iron catalyst is used under a normal pressure; under the action of hydrogen and silicon reagents serving as an accelerant and an oxidant, a side chain of an aromatic hydrocarbon is oxidized into a carbonyl group for generating the corresponding aromatic aldehyde, aromatic ketone and aromatic ester. The method for preparing the aromatic aldehyde, the aromatic ketone and the aromatic ester through a catalytic oxidation reaction, which is provided by the invention, has numerous advantages that a catalyst, reaction raw materials, the oxidant and a silicon reagent are wide in sources and good in stability and is low-cost and environment-friendly; the alkyl aromatic compound is metered to participate in a reaction; the reaction condition is mild; the compatibility of functional groups is good; the scope of application is wide; the reaction selectivity is good; in an optimized reaction condition, the separation yield of a target product can be up to approximately 95 percent.
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Paragraph 0070; 0071
(2017/10/13)
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- Suzuki Coupling of Amides via Palladium-Catalyzed C–N Cleavage of N-Acylsaccharins
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A palladium-catalyzed cross-coupling of activated amides with arylboronic acids has been developed via C–N bond cleavage. This approach demonstrated high tolerance to a variety of alkyl, aryl, heterocyclic and vinyl substituents. Unsymmetrical ketones could be achieved in excellent yield under mild conditions with 1% catalyst loadings. (Figure presented.).
- Wu, Hongxiang,Li, Yue,Cui, Ming,Jian, Junsheng,Zeng, Zhuo
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p. 3876 - 3880
(2016/12/16)
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- MnO2/TBHP: A Versatile and User-Friendly Combination of Reagents for the Oxidation of Allylic and Benzylic Methylene Functional Groups
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In the presence of activated MnO2, tert-butyl hydroperoxide (TBHP) in CH2Cl2 is able to oxidize the allylic and benzylic methylene groups of different classes of compounds. I describe a one-pot oxidation protocol based on two sequential steps. In the first step, carried out at low temperature, MnO2 catalyses the oxidation of the methylene group. This is followed by a second step where reaction temperature is increased, allowing MnO2 both to catalyse the decomposition of unreacted TBHP and to oxidize allylic alcohols that could possibly be formed. The proposed oxidation procedure is generally applicable, although its efficiency, regioselectivity, and chemoselectivity are strongly dependent on the structure of the substrate. A simple and user-friendly synthetic procedure for the oxidation of allylic and benzylic methylene groups to the corresponding conjugated carbonyl derivatives is described. The proposed oxidation protocol is based on the combined use of MnO2 and tert-butyl hydroperoxide, and is generally applicable.
- Serra, Stefano
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p. 6472 - 6478
(2015/10/19)
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- Temporal separation of catalytic activities allows anti-Markovnikov reductive functionalization of terminal alkynes
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There is currently great interest in the development of multistep catalytic processes in which one or several catalysts act sequentially to rapidly build complex molecular structures. Many enzymes - often the inspiration for new synthetic transformations - are capable of processing a single substrate through a chain of discrete, mechanistically distinct catalytic steps. Here, we describe an approach to emulate the efficiency of these natural reaction cascades within a synthetic catalyst by the temporal separation of catalytic activities. In this approach, a single catalyst exhibits multiple catalytic activities sequentially, allowing for the efficient processing of a substrate through a cascade pathway. Application of this design strategy has led to the development of a method to effect the anti-Markovnikov (linear-selective) reductive functionalization of terminal alkynes. The strategy of temporal separation may facilitate the development of other efficient synthetic reaction cascades.
- Li, Le,Herzon, Seth B.
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- Synthesis of new chiral and racemic 1,3-dioxolanes
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A series of chiral 1,3-dioxolanes, 3-12, with >99% ee values, have been synthesized. This is the first study of chiral ketalization reaction starting from ketones with aryl, monosubstituted aryl, and long alkyl chains (C 11-AC13). Their ee values were determined by chiral high-performance liquid chromatography (HPLC) on Chiralcel OD column, using their racemic 1,3-dioxolanes rac-3-12, which were also synthesized for the first time. These chiral and racemic 1,3-dioxolanes were characterizated by infrared, NMR (1H, 13C), mass spectrometry, elemental analysis, optical rotation, and chiral HPLC.
- Kuecuek, Hatice Baspinar,Yusufoglu, Ayse
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p. 1066 - 1070,5
(2012/12/12)
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- Synthesis of new chiral and racemic 1,3-dioxolanes
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A series of chiral 1,3-dioxolanes, 3-12, with >99% ee values, have been synthesized. This is the first study of chiral ketalization reaction starting from ketones with aryl, monosubstituted aryl, and long alkyl chains (C 11-AC13). Their ee values were determined by chiral high-performance liquid chromatography (HPLC) on Chiralcel OD column, using their racemic 1,3-dioxolanes rac-3-12, which were also synthesized for the first time. These chiral and racemic 1,3-dioxolanes were characterizated by infrared, NMR (1H, 13C), mass spectrometry, elemental analysis, optical rotation, and chiral HPLC.
- Kuecuek, Hatice Baspinar,Yusufoglu, Ayse
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p. 1066 - 1070
(2013/01/15)
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- Liquid-crystalline polymorphism of symmetrical azobananas: Bis(4-(4-alkylphenyl)azophenyl) 2-nitroisophtalates
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In this paper we present a series of novel compounds, bis(4-(4-alkylphenyl) azophenyl) 2-nitroisophtalates, which exhibit nematic and banana-type liquidcrystalline phases. The alkyl chain length varies from 1 to 18 carbons. The first ten members of this series exhibit nematic phase. The last eleven compounds exhibit banana-type liquid crystalline phases. The propyl and pentyl derivatives have extra second type of banana mesophase. Copyright Taylor & Francis Group, LLC.
- Zygadlo,Dardas,Nowicka,Hofmann,Galewski
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scheme or table
p. 283 - 291
(2011/08/02)
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- Copper-catalyzed oxidative cleavage of carbon-carbon double bond of enol ethers with molecular oxygen
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A novel CC bond cleavage reaction of aromatic enol ethers (1) to give ketones (2) using molecular oxygen as oxidant is described. Among the examined catalysts (Cu(II), Pd(II), Ru(II), and H+), CuCl2 exhibited the highest activity. The reaction proceeded smoothly with several kinds of substrates.
- Tokunaga, Makoto,Shirogane, Yuki,Aoyama, Hiroshi,Obora, Yasushi,Tsuji, Yasushi
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p. 5378 - 5382
(2007/10/03)
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- Copper-Mediated, Palladium-Catalyzed Coupling of Thiol Esters with Aliphatic Organoboron Reagents
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Thiol esters and B-alkyl-9-BBN derivatives couple in the presence of a copper(I) carboxylate mediator and a palladium catalyst. In contrast to copper-mediated, palladium-catalyzed cross-couplings of thioorganics with boronic acids, the current coupling reaction of 9-BBN derivatives is facilitated by the addition of a base such as Cs2CO3. Under optimized conditions, a variety of thiol esters react with different B-alkyl-9-BBN derivatives giving ketones in moderate to excellent yields.
- Yu, Ying,Liebeskind, Lanny S.
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p. 3554 - 3557
(2007/10/03)
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- Novel Diradical-Mediated Ring Opening Reactions
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Thermo-isomerization of medium- and large-ring 1-phenylcycloalkanols 1e-i at around 650 deg C in a flow reactor system delivers the open-chain phenones 4e-i. A reaction mechanism via an open-chain diradical intermediate, followed by an intramolecular hydrogen transfer is proposed. Thermo-isomerization of α-substituted 1-phenylcyclododecanols 6 proceeds regioselectively under the formation of ω-substituted phenones 7. Furthermore, this novel hydrogen transfer reaction provides a new access to ω-substituted fatty acids.
- Rueedi, Georg,Nagel, Matthias,Hansen, Hans-Juergen
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p. 1210 - 1212
(2007/10/03)
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- Palladium-catalyzed synthesis of aryl ketones from boronic acids and carboxylic acids activated in situ by pivalic anhydride
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A new palladium-catalyzed cross-coupling reaction between arylboronic acids and mixed anhydrides, generated in situ from carboxylic acids and pivalic anhydride, is presented. Optimization of the new catalyst and the reaction conditions led to the development of a convenient one-pot ketone synthesis directly from carboxylic and boronic acids in the presence of different (phosphane)palladium complexes in wet THF at 60 °C. Systematic studies were performed to elucidate the reaction mechanism of this transformation. The scope and the limitations of the new process are demonstrated by the synthesis of 33 functionalized ketones. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Goossen, Lukas J.,Ghosh, Keya
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p. 3254 - 3267
(2007/10/03)
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- Sulfonylated aminothiazoles as new small molecule inhibitors of protein phosphatases
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Based on a previously identified lead structure, SC-ααδ9, we have developed a versatile new chemical scaffold that can be readily modified to generate libraries of both Tyr and dual specificity phosphatase inhibitors with reduced molecular weight and lipophilicity. The most potent analogue identified to date, aminothiazole 8z, inhibits the dual specificity phosphatase Cdc25B with a Ki of 4.6 ± 0.4 μM and a Hill coefficient of 2.
- Wipf, Peter,Aslan, Diana C.,Southwick, Eileen C.,Lazo, John S.
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p. 313 - 317
(2007/10/03)
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- Thiol ester-boronic acid cross-coupling. Catalysis using alkylative activation of the palladium thiolate intermediate
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(matrix presented) Thiol esters and boronic acids do not participate in cross-coupling in the presence of palladium catalysts. However, efficient palladium-catalyzed thiol ester-boronic acid cross-coupling is observed when simple alkylating agents are present. Alkylative conversion of the very stable palladium-thiolate bond to a labile palladium-thioether bond is presumed to be crucial to the catalysis. Of the systems studied, 4-halo-n-butyl thiol esters were most effective in this cross-coupling.
- Savarin, Cecile,Srogl, Jiri,Liebeskind, Lanny S.
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p. 3229 - 3231
(2007/10/03)
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- LIGHT EMITTING LANGMUIR-BLODGETT FILMS
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Langmuir-Blodgett films of europium tri-behenate, behenamido benzoate, 2-(4'-dodecylbenzoyl)benzoate-palmitate (1:1) mixture (EDBB/P) and 2-(4'-eicosoxybenzoyl)benzoate-arachidate (1:1) mixture were prepared and their UV absorption and photoluminescent properties were compared with solutions.Fluorescence intensities of LB films of EDBB/P were greatly enhanced by both effects of the large absorption of excitation light and the efficient energy transfer from organic to Eu(3+) ion.This enhancement is due to the preferable molecular alignment of LB films.
- Sugai, Kiyomi,Miyata, Seizo,Watanabe, Toshiyuki,Okamoto, Yoshiyuki
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p. 271 - 276
(2007/10/02)
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