- Reaction of dialkylmagnesium with carbon monoxide. II
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Reaction of MgEt2 with CO gives Et2CO, Et2CHOH, EtCOCH(OH)Et, EtCOCHEt2 and EtCOC(OH)Et2.The qualitative and quantitative composition of the product mixture was found to be dependent on the MgEt2 concentration and the polarity of solvent.The kinetic results reveal that reaction of CO with MgEt2 and with its dissociation product MgEt3-, followed by the formation of the Et2CO and EtCOCHEt2, respectively.The other compounds are formed in the subsequent reactions.The rate constants of formation of pentanone-3 and 4-ethylhexanone-3 are equal k1 0.292 s-1 and k2 0.450 s-1, respectively.
- Sobota, Piotr,Nowak, Marek
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Read Online
- Simple method for selective oxidation of 1,2-diols in water with KBrO3/KHSO4
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Readily available off-the-shelf KBrO3 and KHSO4 have been used to selectively oxidize 1,2-diols in water as a solvent. Various cyclic 1,2-diols have been tolerated affording their corresponding α-hydroxy ketones in good yields.
- William, Julius M.,Kuriyama, Masami,Onomura, Osamu
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Read Online
- Development of Imidazoline-2-one Derivatives as Potential Antifungal and Anthelminthic Agents: in silico and in vitro Evaluation
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Based on appropriate values of synthetic accessibility concerning from ADMET properties and docking scores by docking against proteins 3OZU and 1OJ0, a series of 4,5-diphenyl-1H-imidazol-2-ones (I1?15) were synthesized. The key intermediate, 2-hydroxy-1,2-disubstitutedethanones (E1?15) were prepared by benzoin condensation using 2:1 ratio of aromatic aldehydes and thiamine in the presence of alkali. Further, these cyclized ethanones (E1?15) were treated with urea to yield 4,5-diphenyl-1H-imidazol-2-one derivatives (I1?15) and were characterized by IR,1H NMR, Mass spectra, and CHNO analysis. The synthesized compounds were screened for their anthelmintic potential on Pheretima Posthuma along with standard albendazole, and antifungal activity (minimum inhibitory concentration method) on Candida albicans and Aspergillus niger along with standard miconazole. The results revealed that among all the tested compounds I3, I4, and I7 show considerable synthetic accessibility, docking scores, anthelminthic, and antifungal activity.
- Chilamakuru, Naresh Babu,Mallela, Vijaya Jyothi,Peraman, Ramalingam,Shaik, Shakir Basha,Simham, Venu,Singirisetty, Triveni
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p. 423 - 433
(2021/11/24)
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- Sol-gel synthesis of ceria-zirconia-based high-entropy oxides as high-promotion catalysts for the synthesis of 1,2-diketones from aldehyde
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Efficient Lewis-acid-catalyzed direct conversion of aldehydes to 1,2-diketones in the liquid phase was enabled by using newly designed and developed ceria–zirconia-based high-entropy oxides (HEOs) as the actual catalysts. The synergistic effect of various cations incorporated in the same oxide structure (framework) was partially responsible for the efficiency of multicationic materials compared to the corresponding single-cation oxide forms. Furthermore, a clear, linear relationship between the Lewis acidity and the catalytic activity of the HEOs was observed. Due to the developed strategy, exclusively diketone-selective, recyclable, versatile heterogeneous catalytic transformation of aldehydes can be realized under mild reaction conditions.
- Dinjar, Kristijan,Djerdj, Igor,Koj?inovi?, Jelena,Kukovecz, ákos,Markovi?, Berislav,Mileti?, Aleksandar,Nagy, Sándor Balázs,Sapi, Andras,Stenzel, David,Széchenyi, Aleksandar,Szenti, Imre,Tang, Yushu,Tatar, Dalibor,Varga, Gábor,Ziegenheim, Szilveszter
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- Preparation Method for 2,3-pentanedione
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A preparation method for 2,3-pentanedione, including the steps of adding one or both of 3-hydroxy-2-pentanone and 2-hydroxy-3-pentanone into water and conducting mixing, and introducing ozone at the temperature of 3-20° C. for a reaction to obtain 2,3-pentanedione. The synthesis process of the present invention uses ozone for oxidizing a mixture containing 3-hydroxy-2-pentanone and 2-hydroxy-3-pentanone, acetic acid is used as a cocatalyst, reaction conditions are mild, the operation process is simple, the product yield is high, and the cost is low.
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Paragraph 0018; 0019; 0024; 0025; 0029
(2019/04/25)
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- Preparation method of 2,3-pentanedione
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The invention discloses a preparation method of 2,3-pentanedione. The preparation method comprises the following steps: one or two of 3-hydroxy-2-pentanone and 2-hydroxy-3-pentanone is/are added to water and uniformly mixed with water, ozone is introduced at the temperature of 3-20 DEG C for a reaction, and 2,3-pentanedione is obtained. According to the synthesis process, ozone is adopted to oxidize the mixture containing 3-hydroxy-2-pentanone and 2-hydroxy-3-pentanone, acetic acid is adopted as a cocatalyst, reaction conditions are mild, and operation process is simple; product yield is high;cost is low; the method has the advantages of being safe and environmentally friendly, and no wastewater is produced.
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Paragraph 0004; 0017-0019; 0024-0026; 0031-0033
(2018/09/08)
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- Preparation method of acyloin compounds
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The invention relates to a preparation method of acyloin compounds, and belongs to the field of fine chemical industry. A new catalyst 1-n butyl benzimidazole hydrochloride is provided for synthesis of the acyloin compounds, and the products have the advantages of good quality and less side reactions; deficiencies existed in the prior art are overcome.
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Paragraph 0018; 0019; 0021; 0022
(2017/08/27)
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- Synthesizing method of 3,4-heptadione
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The invention provides a synthesizing method of 3,4-heptadione. The synthesizing method comprises the following steps of (1) using propionaldehyde and butyraldehyde as raw materials, adding a main catalyst, and reacting under the alkaline condition, so as to synthesize 4-hydroxyl-3-heptanone; (2) mixing the 4-hydroxyl-3-heptanone, sulfuric acid and an oxidant to oxidize, so as to obtain the 3,4-heptadione. The synthesizing method of the 3,4-heptadione has the advantages that the main raw materials are the propionaldehyde and butyraldehyde, the obtaining of the raw materials is easy, the cost is low, and the production cost is reduced.
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Paragraph 0018; 0027; 0031; 0035
(2017/09/18)
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- Regio- and Stereoselective Aliphatic–Aromatic Cross-Benzoin Reaction: Enzymatic Divergent Catalysis
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The catalytic asymmetric synthesis of chiral 2-hydroxy ketones by using different thiamine diphosphate dependent enzymes, namely benzaldehyde lyase from Pseudomonas fluorescens (PfBAL), a variant of benzoylformate decarboxylase from?Pseudomonas putida (PpBFD-L461A), branched-chain 2-keto acid decarboxylase from Lactococcus lactis (LlKdcA) and a variant of pyruvate decarboxylase from Acetobacter pasteurianus (ApPDC-E469G), was studied. Starting with the same set of substrates, substituted benzaldehydes in combination with different aliphatic aldehydes, PfBAL and PpBFD-L461A selectively deliver the (R)- and (S)-2-hydroxy-propiophenone derivatives, respectively. The (R)- and (S)-phenylacetylcarbinol (1-hydroxy-1-phenylacetone) derivatives are accessible in a similar way using LlKdcA and ApPDC-E469G, respectively. In many cases excellent stereochemical purities (>98 % enantiomeric excess) could be achieved. Hence, the regio- and stereochemistry of the product in the asymmetric aliphatic–aromatic cross-benzoin reaction can be controlled solely by choice of the appropriate enzyme or enzyme variant.
- Beigi, Maryam,Gauchenova, Ekaterina,Walter, Lydia,Waltzer, Simon,Bonina, Fabrizio,Stillger, Thomas,Rother, D?rte,Pohl, Martina,Müller, Michael
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supporting information
p. 13999 - 14005
(2016/09/21)
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- Efficient Domino Hydroformylation/Benzoin Condensation: Highly Selective Synthesis of α-Hydroxy Ketones
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An improved domino hydroformylation/benzoin condensation to give α-hydroxy ketones has been developed. Easily available olefins are smoothly converted into the corresponding α-hydroxy ketones in high yields with excellent regioselectivities. Key to success is the use of a specific catalytic system consisting of a rhodium/phosphine complex and the CO2 adduct of an N-heterocyclic carbene. 2 for 1: An improved domino hydroformylation/benzoin condensation of olefins has been developed in the presence of a specific catalytic system consisting of a rhodium/phosphine complex and the CO2 adduct of an N-heterocyclic carbene.
- Dong, Kaiwu,Sang, Rui,Soule, Jean-Francois,Bruneau, Christian,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 18033 - 18037
(2015/12/24)
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- Tandem hydroformylation/acyloin reaction - The synergy of metal catalysis and organocatalysis yielding acyloins directly from olefins
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A novel, atom efficient, orthogonal tandem catalysis was developed yielding acyloin products (α-hydroxy ketones) directly from olefins under hydroformylation conditions. The combination of a metal-catalysed hydroformylation and an organocatalysed acyloin reaction provides three atom efficient C-C bond formations to linear, multifunctional molecules via linkage of the intermediate n-aldehydes. Additionally, the rhodium catalyst system gives a high n/bra ratio with an exclusive conversion of the terminal double bond in the hydroformylation and the n-aldehydes are converted selectively to their acyloins.
- Ostrowski, Karoline A.,Fassbach, Thiemo A.,Vorholt, Andreas J.
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supporting information
p. 1374 - 1380
(2015/07/07)
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- Boronic acid-catalyzed selective oxidation of 1,2-diols to α-hydroxy ketones in water
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The activation of 1,2-diols through formation of boronate esters was found to enhance the selective oxidation of 1,2-diols to their corresponding α-hydroxy ketones in aqueous medium. The oxidation step was accomplished using dibromoisocyanuric acid (DBI) as a terminal chemical oxidant or an electrochemical process. The electrochemical process was based on the use of platinum electrodes, methylboronic acid [MeB(OH)2] as a catalyst and bromide ion as a mediator. Electro-generated OH- ions (EGB) at the cathode acted as a base and "Br+" ion generated at the anode acted as an oxidant. Various cyclic and acyclic 1,2-diols as substrates were selectively oxidized to the corresponding α-hydroxy ketones via their boronate esters by the two oxidative methods in good to excellent yields.
- William, Julius M.,Kuriyama, Masami,Onomura, Osamu
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supporting information
p. 934 - 940
(2014/04/03)
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- METHOD FOR PRODUCING ALPHA - HYDROXY KETONE COMPOUND
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The present invention relates to a specific thiazolium salt used for producing an ∝-hydroxy ketone compound, and a method for producing an ∝-hydroxy ketone compound by carrying out a coupling reaction of an aldehyde compound in the presence of a base compound and the specific thiazolium salt.
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Paragraph 0144
(2013/03/26)
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- PROCESS FOR PRODUCING ALPHA-HYDROXYKETONE COMPOUND
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An object of the present invention is to produce an α-hydroxyketone compound easily and effectively. Provided is a process for producing an α-hydroxyketone compound comprising a stirring step of stirring one or more aldehyde compounds or polymers thereof in the presence of a base and an imidazolinium salt represented by the formula (1): wherein R1 and R2 each independently represent a hydrogen atom, an alkyl group optionally having a substituent or an aryl group optionally having a substituent, or R1 and R2 are bound to each other to form a ring together with carbon atoms to which they bind, R3 and R4 each independently represent an aryl group having one or more electron withdrawing groups, and X? represents an anion.
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Paragraph 0119
(2013/11/05)
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- BIOFUEL PRODUCTION
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Methods, enzymes, recombinant microorganism, and microbial systems are provided for converting polysaccharides, such as those derived from biomass, into suitable monosaccharides or oligosaccharides, as well as for converting suitable monosaccharides or oligosaccharides into commodity chemicals, such as biofuels. Commodity chemicals produced by the methods described herein are also provided. Commodity chemical enriched, refinery-produced petroleum products are also provided, as well as methods for producing the same.
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- One-pot synthesis of α-hydroxy ketones from captodative formyl(amino)alkenes
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α-Hydroxy or α-amino ketones were prepared in one step via reactions between captodative formyl(amino)alkenes and Grignard reagents.
- Rulev, Alexander Yu.,Novokshonov, Vladimir V.,Chuvashev, Yuri A.,Fedorov, Sergei V.,Larina, Lyudmila I.
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- New coupling reactions of some acyl chlorides with samarium diiodide in the presence of samarium: Carbinols from three acyl units
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A mixture of samarium(II) iodide and samarium can induce a coupling reaction of three molecules of alkanoyl halide to give trialkylcarbinols of 2-hydroxy-1,3-diones. When aliphatic, unbranched alkanoyl chlorides are used, this new coupling reaction provides trimeric products as the main reaction products. Tetrahydropyran (THP) proved superior as the solvent because no ring-opening and subsequent reaction with the alkanoyl halides was observed under the reaction conditions, unlike when THF was used. Wiley-VCH Verlag GmbH, 2000.
- Clausen, Christian,Weidner, Ingo,Butenschoen, Holger
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p. 3799 - 3806
(2007/10/03)
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- Elemental fluorine. Part 7. New oxidation methodology
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Reaction of fluorine with water in the presence of acids provides new oxidants for 'in-situ' oxidation of ketones. Direct reaction of fluorine with anhydrous alcohols and 1,2-diols provides simple methodology for oxidation to corresponding secondary ketones or α-hydroxy ketones.
- Chambers, Richard D.,Hutchinson, John,Sandford, Graham,Shah, Aneela,Vaughan, Julian F. S.
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p. 15833 - 15842
(2007/10/03)
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- Convenient Preparation of 'High-Surface Sodium' in Liquid Ammonia: Use in the Acyloin Reaction
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'Sodium on solid support' (5-20 wt.% of Na on NaCl, glass powder, poly(ethylene) and poly(propylene)) can be conveniently prepared via low-temperature (-33°C) deposition of sodium from its solution in liquid ammonia. Use of this reagent in the acyloin reaction of carboxylic esters gave the corresponding products in good yields.
- Makosza, Mieczyslaw,Grela, Karol
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p. 267 - 268
(2007/10/03)
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- Catalytic action of azolium salts. VI. Preparation of benzoins and acyloins by condensation of aldehydes catalyzed by azolium salts
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Benzoins 4 (2-hydroxyethanones substituted with aryl groups at the 1- and 2-positions) were prepared by self-condensation of aromatic aldehydes 3 using catalytic amounts of azolium salts 1 and 2 in excellent yields. 1,3-Dimethylbenzimidazolium iodide (2) was an effective catalyst for the preparation of acyloins 6 (2-hydroxyethanones substituted with alkyl groups at the 1- and 2-positions) by self-condensation of aliphatic aldehydes 5. On the other hand, an attempt at the condensation of hexanal (5d) catalyzed by 1,3-dimethylimidazolium iodide (1) failed to yield the acyloin 6d, and instead the aldol-type condensed product 8d was obtained.
- Miyashita,Suzuki,Iwamoto,Higashino
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p. 2633 - 2635
(2007/10/02)
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- Origin of α-Hydroxy Ketones in the Osmium Tetroxide-Catalyzed Asymmetric Dihydroxylation of Alkenes
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The origin and the mechanism of formation of α-hydroxy ketones in the osmium tetroxide-catalyzed asymmetric cis-dihydroxylation (ADH) of alkenes in the presence of tert-butyl hydroperoxide is described.The formation of α-hydroxy ketones has been established to proceed through either the hydration of monooxobisglycolate ester 2 followed by oxidation with tert-butyl hydroperoxide (TBHP) or by acid-catalyzed addition of TBHP on the intermediate bisglycolate ester 2.On the basis of the mechanistic insight, it has been possible to shut down the formation of α-hydroxy ketones and other side products in the ADH reaction, even when TBHP is used as an oxygen source.It is possible to prepare α-hydroxy ketones in good yields but the optical purity of ketols has been found to be very low, which not only shed significant light on the mechanism of their formation, but also delineated the improbability of syntesizing them in optically active forms by ADH reaction of alkenes.
- Lohray, Braj B.,Bhushan, Vidya,Kumar, R. Krishna
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p. 1375 - 1380
(2007/10/02)
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- 1,4,5-Trialkyl imidazole system anti-inflammatory properties of new substituted derivatives
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In an investigation of the anti-inflammatory properties of five-membered ring nitrogen-containing heterocyclic compounds, two series of derivatives of imidazole were prepared by altering the sites of substitution and by joining aliphatic chains to the nitrogen atom in the 1 position of the imidazole ring. Some of them were more potent inhibitors of carragenan-induced edema than indomethacin. An electron spin resonance study indicated that these compounds possess anti-radical activity.
- Fatimi,Lagorce,Duroux,Chabernaud,Buxeraud,Raby
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p. 698 - 701
(2007/10/02)
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- Synthesis and antithyroid activity of 1,4,5-trialkyl 2-thioimidazole derivatives
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A series of compounds based on the structure of MTI (1-methyl-2-thioimidazole) were synthesized by condensation of α-hydroxyketones and alkylthioureas. The α-hydroxyketones were obtained by a radical reaction in the presence of sodium and the alkyl ester, while the alkylthioureas were prepared by nucleophilic addition of ammonia on an alkylisothiocyanate. The antithyroid activity of the 13 compounds prepared was evaluated in vitro by determination of the concentrations which led to a 50% inhibition (IC50) of the activity of thyroid peroxidase, and in vivo by assay of thyroid hormones levels and histological examination of the thyroid gland in rats treated chronically with the compounds. 1-methyl-4,5-dipropyl 2-thioimidazole (compound 10) was found to have the highest antithyroid activity of the 13 compounds synthesized.
- Fatimi,Lagorce,Chabernaud,Comby,Buxeraud,Raby
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p. 253 - 257
(2007/10/02)
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- Synthesis and inhibitory effects of 1,4,5-trialkyl-2-thioimidazole derivatives on platelet aggregation
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New 1,4,5-trialkyl-2-thioimidazole have been synthesized by the condensation of α-hydroxyketones and alkylthioureas. The in vitro platelet aggregation inhibiting effect of prepared compounds on human platelets was studied in the presence of ADP and collagen as inducers. The formation of thromboxane B2 (TXB2) was inhibited. 1-isopropyl-4,5-dimethyl-2-thioimidazole has the greatest aggregation inhibiting effect, about 4 times that of aspirin. It highly inhibits the production of TXB2 (68,5% for a final concentration of 0,04 M).
- Fatimi,Lagorce,Chabernaud,Buxeraud,Raby
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p. 151 - 155
(2007/10/02)
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- Selectivity in the Oxidation of Aliphatic Ketones by Thallic Sulphate in Aqueous Medium
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The effects of temperature, structure and sulphuric acid concentration on the selectivity of the oxidation of aliphatic ketones (R1COR2) (1a-g) by thallic sulphate have been investigated.With increasing temperature the quantity of internal α-hydroxyketone (3a-d) decreases and the quantity of 1-hydroxyketone (2a-d) increases in the oxidation of methyl alkyl ketone (R2>CH3) (1a-d).The same concerns to the oxidation products of hexan-3-one (1e): 2-hydroxy-hexan-3-one (2e) and 4-hydroxy-hexan-3-one (3e), respectively. "The inverse selectivity temperature" (IST) for oxidation of linear methyl alkyl ketones (1a-c) and hexan-3-one (1e) has been found.With the use of the linear free-energy relationship it has been found that the selectivity of the reaction decreases with increasing the polar and steric effects of substituents R1,R2.With increasing the sulphuric acid concentration the selctivity of the oxidation of methyl alkyl ketones (1a, 1d) increases.
- Pechal, Miroslav,Strasak, Milan
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p. 374 - 380
(2007/10/02)
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- Photochimie en solution. XXIV. Mecanisme de l'addition des aldehydes aux double liaisons ethyleniques activees par des groupements attracteurs d'electrons
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The mechanism of the photochemical addition of aliphatic aldehydes to electron-deficient olefins has been rationalized.No addition to α,β-unsaturated ketones was observed when the latter were excited.The reaction can be explained by a first self-quenching step of the aliphatic aldehyde involving its lowest triplet state, which is reached with a moderate quantum yield (0.5).The radical R-C.=O produced in the self quenching process adds to the olefin at the more positively-charged carbon atom.The reaction ends by a hydrogen atom exchange between the radical produced by this addition and the radical R-C.HOH.The quantum yield of the product formation is much higher with benzaldehyde owing to the almost unity value of the intersystem crossing, but it competes with the formation of benzile.
- Kawenoki, Isabelle,Maurel, Daniele,Kossanyi, Jean
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p. 385 - 390
(2007/10/02)
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