- Study on the synthesis of 1,2-diketones
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A novel method is discussed for preparation of 1,2-diketones: Esters 1 was used as starting material, the intermediate enol 2 was obtained from sodium and trimethylsilyl chloride via acyloin condensation reaction, while bromine water was used in the further experiment as the oxidation reagent to oxidize compound 2 in the mixed solvent THF/H2O. Four kinds of 1,2-diketones have been synthesized in the new way, one is straight chain compound 3a, 3b and the other is ring compound 3c, 3d. The target compounds were confirmed by IR and 1HNMR. Copyright Taylor & Francis Group, LLC.
- Liu, Peng,Zhang, Yu-Mei,Zhang, Hong-Li
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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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- Synthesis Method of 3,4-hexanedione
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A synthesis method of 3,4-hexanedione comprises a step of 4-hydroxy-3-hexanonen oxidation, and in the step of 4-hydroxy-3-hexanonen oxidation, water is used as a catalyst, acetic acid is used as a cocatalyst, and ozone is used as an oxidizing agent to carry out an oxidation reaction on 4-hydroxy-3-hexanonen, and after the reaction, distillation under reduced pressure is carried out to obtain the 3,4-hexanedione. According to the synthesis method of 3,4-hexanedione in the invention, in the process of 4-hydroxy-3-hexanone oxidation, the 4-hydroxy-3-hexanone is placed in the water, the ozone is used for oxidation on the 4-hydroxy-3-hexanone, and the acetic acid is used as the cocatalyst, so that the entire oxidation reaction process is mild in conditions and simple to operate, no sewage is produced when the final product (3,4-hexanedione) is obtained, and the yield is greatly increased.
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Paragraph 0017; 0019; 0022; 0025
(2018/12/04)
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- Silver-Catalyzed Decarboxylative Couplings of Acids and Anhydrides: An Entry to 1,2-Diketones and Aryl-Substituted Ethanes
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Silver-catalyzed oxidative decarboxylative couplings of carboxylic acids and anhydrides to produce 1,2-diketones and substituted ethanes were developed. This reaction allows the generation of acyl or alkyl radicals by decarboxylation of the corresponding α-keto acids, alkyl acids and anhydrides, which are sequentially coupled to efficiently construct a new C?C bond. This reaction represents a carboxylic acid decarboxylative alternative that employs a radical termination strategy. (Figure presented.).
- Zou, Hua-Xu,Li, Yang,Yang, Yuan,Li, Jin-Heng,Xiang, Jiannan
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supporting information
p. 1439 - 1443
(2018/02/26)
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- Insertion of an Isolable Dialkylstannylene into C-Cl Bonds of Acyl Chlorides Giving Acyl(chloro)stannanes
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The reactions of isolable dialkylstannylene 1 with 1-adamantanoyl, 2,2-dimethylpropanoyl, benzoyl, and substituted benzoyl chlorides afford the corresponding acyl(chloro)stannanes in good yields. Similar reactions with more reactive acetyl and propanoyl c
- Lu, Qiong,Yan, Chenting,Xiao, Xu-Qiong,Li, Zhifang,Wei, Ningka,Lai, Guoqiao,Kira, Mitsuo
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p. 3633 - 3637
(2017/10/03)
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- Heterogenization of ketone catalyst for epoxidatio by low pressure plasma fluorination of silica gel supports
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Low pressure plasma was used for preparing heterogeneous organocatalysts 2-(A)-(C) suitable for dioxirane-mediated epoxidations. Heterogenization was accomplished by adsorption of the methyl perfluoroheptyl ketone (2) on fluorinated supports (A)-(C) deriving from the treatment of commercial C8-silica gel in low pressure plasma fed with fluorocarbons. Catalyst 2-(C) proved to be the most efficient one, promoting epoxidation of an array of alkenes, including unsaturated fatty esters like methyl oleate (10) and the triglyceride soybean oil (11), with the cheap potassium peroxymonosulfate KHSO5 (caroate) as a green oxidant. Notably, the perfluorinated matrix gives rise to the activation of caroate, generating singlet oxygen. Materials were characterized by infrared Attenuated Total Reflectance spectroscopy (ATR-FTIR), X-ray Photoelectron Spectroscopy (XPS) and Emission Scanning Electron Microscope (FESEM).
- D'Accolti, Lucia,De Vietro, Nicoletta,Fanelli, Fiorenza,Fusco, Caterina,Nacci, Angelo,Fracassi, Francesco
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- Preparation method of 1,2-diketone derivative
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The invention discloses a preparation method of a 1,2-diketone derivative. The method comprises the step of enabling a raw material 1,3-diketone derivative to react with a cheap and easily obtained industrial product 2,2,6,6-tetramethyl-1-piperidinyloxy under the catalysis of copper so as to obtain the product 1,2-diketone derivative. According to the preparation method, the 1,3-diketone derivative is used as an initiator, and the raw material is easy to obtain and wide in variety; by utilizing the preparation method, the obtained product types are varied, can be directly used, and can be used for other further reactions; in addition, the reagent dosage in the reaction is less, the pollution is reduced, and the production cost is lowered; moreover the reaction conditions are mild, the reaction operation and the after-treatment process are simple, the reaction time is short, the yield is high, and the preparation method is suitable for industrial production.
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Paragraph 0031
(2016/10/08)
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- Synthesis of ferrocene derivatives with planar chirality via palladium-catalyzed enantioselective C-H bond activation
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The first catalytic and enantioselective C-H direct acylation of ferrocene derivatives has been developed. A series of 2-acyl-1-dimethylaminomethylferrocenes with planar chirality were provided under highly efficient and concise one-pot conditions with up to 85% yield and 98% ee. The products obtained could be easily converted to various chiral ligands via diverse transformations.
- Pi, Chao,Cui, Xiuling,Liu, Xiuyan,Guo, Mengxing,Zhang, Hanyu,Wu, Yangjie
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supporting information
p. 5164 - 5167
(2014/12/11)
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- Oxone-mediated oxidative cleavage of β-keto esters and 1,3-diketones to α-keto esters and 1,2-diketones in aqueous medium
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A versatile and highly efficient method for the direct synthesis of α-keto esters and 1,2-diketones has been developed. This approach utilizes the oxidative cleavage of a variety of β-keto esters and 1,3-diketones mediated by an Oxone/aluminum trichloride system. The simple one-step oxidation reaction proceeded selectively in aqueous media to afford products in high yields, short reaction times, and environmentally benign conditions.
- Stergiou, Anastasios,Bariotaki, Anna,Kalaitzakis, Dimitris,Smonou, Ioulia
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p. 7268 - 7273
(2013/08/15)
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- CaO-catalyzed aerobic oxidation of α-hydroxy ketones: Application to one-pot synthesis of quinoxaline derivatives
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The aerobic oxidation of α-hydroxy ketones into α-diketones catalyzed by CaO is compared with the same reaction catalyzed by other metal oxides. The catalytic activities of the various metal oxides were proportional to their surface basicities. The direct conversion of α-hydroxy ketones into quinoxalines via CaO-catalyzed aerobic oxidation followed by in situ reaction with 1,2-diaminoaromatics is also achieved. Various types of quinoxalines were synthesized in the presence of the CaO catalyst and molecular oxygen. It was also found that the CaO catalyst was reusable without any loss of its catalytic activity.
- Hara, Takayoshi,Takami, Yukihiro,Ichikuni, Nobuyuki,Shimazu, Shogo
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experimental part
p. 488 - 490
(2012/08/07)
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- Direct carbo-acylation reactions of 2-arylpyridines with α-diketones via Pd-catalyzed C-H activation and selective C(sp2)-C(sp2) cleavage
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An efficient carbo-acylation reaction of 2-arylpyridines with α-diketones via Pd-catalyzed C-H bond activation and C-C bond cleavage in the presence of TBHP was developed that generated aryl ketones in good yields. The highly selective formation of aryl ketones was observed when 2-arylpyridines reacted with aromatic/aliphatic α-diketones.
- Zhou, Wei,Li, Hongji,Wang, Lei
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supporting information
p. 4594 - 4597
(2012/10/29)
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- New synthetic strategy for high-enantiopurity N-protected α-amino ketones and their derivatives by asymmetric hydrogenation
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Asymmetric hydrogenation of α-dehydroamino ketones catalyzed by a rhodium-chiral phosphorus ligand complex (up to 99% ee, 1000 TON), represents an efficient approach to chiral α-amino ketones. The reduction of α-amino ketones catalyzed by palladium on carbon (Pd/C) leads to amphetamine precursors with quantitative yield and no significant enantioselectivity loss.
- Sun, Tian,Hou, Guohua,Ma, Miaofeng,Zhang, Xumu
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supporting information; experimental part
p. 253 - 256
(2011/04/16)
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- Adducts of thianthrene- and phenoxathiin cation radical salts with symmetrical alkynes. Structure and formation of cumulenes on alumina leading to α-diketones, α-hydroxyalkynes, and α-acetamidoalkynes
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Thianthrene cation radical tetrafluoroborate (Th.+BF 4-) added to 2-butyne, 3-hexyne, 4-octyne, and 5-decyne in MeCN to form trans bisadducts E(Th+)C=C(Th+)R, where E = Me, Et, Pr, Bu (7a-d). Phenoxathiin cation radical tetrafluoroborate (PO .+BF4-) added similarly to the last three alkynes to form adducts E(PO+)C=C(PO+)E, 8b-d. Cyclic monoadducts were not found. The trans structures of 7 and 8 were deduced with X-ray crystallography (7c) and NME spectroscopy. When solutions of adducts in CHCl3 and MeCN were deposited on activated alumina, elimination of thianthrene (Th) and phenoxathiin (PO) occurred almost quantitatively. Detailed studies with (7b-d) indicated that a cumulene (15) was formed by the elimination of Th and that 15 was subsequently converted into small amounts of other products. In CHCl3, these products were the respective alkyne, thianthrene 5-oxide, an α-diketone (11), an α-hydroxyalkyne (12), and hydrogen. The same products were formed in MeCN along with an α-acetamidoalkyne (13). The formation of 15 and products derived from it is explained and was confirmed by preparation and reactions of 2,3,4-hexatriene.
- Shine, Henry J.,Rangappa, Paramashivappa,Marx, John N.,Shelly, Dennis C.,Ould-Ely, Teyeb,Whitmire, Kenton H.
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p. 3877 - 3883
(2007/10/03)
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- A novel method of synthesis of 1,2-diketones from 1,2-diols using N-bromosuccinimide
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A simple and convenient procedure is reported for the synthesis of benzils and aliphatic 1,2-diketones of cyclic and open chain compounds from corresponding hydrobenzoins and 1,2-diols by refluxing with N-bromosuccinimide in carbon tetrachloride in presence or absence of pyridine.
- Khurana, Jitender M.,Kandpal, Bhaskar M.
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p. 4909 - 4912
(2007/10/03)
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- Electroreductive coupling of aromatic acyl bromides to 1,2-diketones
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The direct electroreduction of aromatic acyl bromides gave aromatic 1,2-diketones. The best result was obtained using a Pb cathode in acetonitrile containing Bu4NClO4 as a supporting electrolyte. Aromatic acyl bromides substituted by an electron-donating group afforded 1,2-diketones in moderate-to-good yields, whereas acylated endiols were formed exclusively from aromatic acyl bromides substituted by an electron-withdrawing group.
- Kise,Ueda
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p. 755 - 756
(2007/10/03)
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- Atmospheric Chemistry of Selected Hydroxycarbonyls
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Using a relative rate method, rate constants have been measured at 296 ± 2 K for the gas-phase reactions of the OH radical with 1-hydroxy-2-butanone, 3-hydroxy-2-butanone, 1-hydroxy-3-butanone, 1-hydroxy-2-methyl-3-butanone, 3-hydroxy-3-methyl-2-butanone, and 4-hydroxy-3-hexanone, with rate constants (in units of 10-12 cm3 molecule-1 s-1) of 7.7 ± 1.7, 10.3 ± 2.2, 8.1 ± 1.8, 16.2 ± 3.4, 0.94 ± 0.37, and 15.1 ± 3.1, respectively, where the error limits include the estimated overall uncertainty in the rate constant for the reference compound. Rate constants were also measured for reactions with NO3 radicals and O3. Rate constants for the NO3 radical reactions (in units of 10-16 cm3 molecule-1 s-1) were 1-hydroxy-2-butanone, 3 were observed, and upper limits to the rate constants of -19 cm3 molecule-1 s-1 were derived for all six hydroxycarbonyls. The dominant tropospheric loss process for the hydroxycarbonyls studied here is calculated to be by reaction with the OH radical.
- Aschmann, Sara M.,Arey, Janet,Atkinson, Roger
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p. 3998 - 4003
(2007/10/03)
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- Asymmetric hydrogenation method of a ketonic compound and derivative
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The present invention relates to a process for the asymmetric hydrogenation of a ketonic compound and derivative. The invention relates to the use of optically active metal complexes as catalysts for the asymmetric hydrogenation of a ketonic compound and derivative. The process for the asymmetric hydrogenation of a ketonic compound and derivative is characterized in that the asymmetric hydrogenation of said compound is carried out in the presence of an effective amount of a metal complex comprising as ligand an optically active diphosphine corresponding to one of the following formulae: STR1
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- A direct conversion of vic-diols into 1,2-diketones with aqueous hydrogen peroxide catalyzed by peroxotungstophosphate (PCWP)
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α-Hydroxy ketones and vic-diols were successfully oxidized to the corresponding diketones with acqueous hydrogen peroxide in the presence of a catalytic amount of peroxotungstophosphate (PCWP). This method provides a straightforward route of 1,2-diketones which are difficult to prepare by conventional oxidation of vic-diols.
- Iwahama, Takahiro,Sakaguchi, Satoshi,Nishiyama, Yutaka,Ishii, Yasutaka
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p. 1523 - 1526
(2007/10/02)
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- Facile Synthesis of α-Keto Carbonyl Compounds by Indirect Anodic Oxidation
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Secondary alcohols having a carbonyl group at the neighboring carbon atom were electrochemically oxidized to the corresponding α-keto carbonyl compounds in good yields.Thus, aromatic α-hydroxyl esters were easily transformed to arylglyoxylates in excellent yields using an undivided cell while efficient anodic oxidation of α-hydroxyl ketones and aliphatic α-hydroxyl esters successfully proceeded in a divided cell to give the corresponding α-keto carbonyl compounds.
- Maekawa, Hirofumi,Ishino, Yoshio,Nishiguchi, Ikuzo
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p. 1017 - 1020
(2007/10/02)
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- Cobalt(II)-Catalyzed Reaction of Aldehydes with Acetic Anhydride under an Oxygen Atmosphere: Scope and Mechanism
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The reaction of aldehydes with acetic anhydride in the presence of catalytic cobalt(II) chloride under an oxygen atmosphere at ambient temperature is dependent upon the reaction medium.Aliphatic aldehydes react in acetonitrile to give 1,2-diones whereas the aromatic aldehydes are acylated to yield the corresponding acylals.On the other hand, carboxylic acids are obtained from aliphatic and aromatic aldehydes by conducting the reaction in dichloroethane or benzene.Cobalt(II) chloride in acetonitrile catalyzes the conversion of aliphatic aldehydes to the correspondinganhydrides in the absence of acetic anhydride whereas aromatic aldehydes remain largely unaffected under these conditions.A preliminary mechanistic study in three different solvents (i.e. acetonitrile, dichloroethane, and DMF) has revealed that in acetonitrile and in the presence of acetic anhydride, aliphatic aldehydes behave differently than aromatic aldehydes.Some trapping experiments using methyl acrylate and stilbene have been conducted to demonstrate the occurence of an acyl cobalt and peroxyacyl cobalt intermediate during these reactions.
- Bhatia, Beena,Punniyamurthy, T.,Iqbal, Javed
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p. 5518 - 5523
(2007/10/02)
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- One-flask preparation of symmetrical ketones and 1,2-diketones from esters
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A convenient one-flask preparation of a series of symmetrical 1,2-diketones from esters is reported using sodium metal induced acyloin condensation followed by reaction with thionyl chloride. Symmetrical monoketones were obtained when after initial acyloin condensation, the reaction mixture is oxidized with aqueous sodium bromate and then reacted with thionyl chloride. Preparative aspects, the scope of the reaction, and the suggested mechanism are discussed.
- Olah,Wu
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p. 1177 - 1179
(2007/10/02)
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- Synthesis of Dialkyl- and Alkylacylrhenium Complexes by Alkylation of Anionic Rhenium Complexes at the Metal Center. Mechanism of a Double Carbonylation Reaction That Proceeds via the Formation of Free Methyl Radicals in Solution
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The site of alkylation of salts of acylrhenates such as Li(1+)(1-) (1) can be controlled by adjusting the hardness of the alkylating agent.Thus, treatment of 1 with the hard alkylating agent (CH3)3OPF6 gives predominantly the clssical Fischer carbene complex Cp(CO)2Re=C(OCH3)(CH3) (2), whereas reaction with the softer electrophile CH3I leads almost exclusively to the new metal-alkylated complex Cp(CO)2Re(CH3)(COCH3) (3).The structure of 3 has been determined by X-ray diffraction.The availability of this material, a relatively rare example of astable alkylacylmetal complex, has provided an opportunity to study the products and mechanisms of its carbon-carbon bond-forming decomposition reactions.Thermally, the alkyl acyl complex undergoes simple reductive elimination, leading (in the presence of a metal-scavenging ligand L) to a quantitative yield of acetone and CpRe(CO)2(L).Photochemically, a more complicated reaction takes place, especially under 20 atm of CO, where CpRe(CO)3 and 2,3-butanedione are formed.Strikingly, irradiation of Cp(CO)2Re(CH3)2 (9) under 20 atm of CO gives products identical with those formed from 3.Labeling experiments using (13)CO and mixtures of acetyl- and propionylrhenium complexes are inconsistent with a mechanism involving simple migratory CO insertion followed by reductive elimination.They are, however, consistent with metal-carbon bond homolysis leading to methyl and acetyl radicals, followed by carbonylation of the methyl radicals to give a second source of acetyl radicals; these reactive intermediates then dimerize to give 2,3-butanedione.Confirmation of this mechanism was obtained by trapping all the initially formed radicals withhalogen donors.BrCCl3, proved to be much more efficient than CCl4 for this purpose: irradiation of alkyl acyl complex 3 in the presence of BrCCl3 diverted the reaction completely from 2,3-butanedione production, giving instead CH3Br, CH3COBr, Cp(CO)2Re(CH3)Br, and Cp(CO)2Re(CH3CO)Br.
- Goldberg, Karen I.,Bergman, Robert G.
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p. 1285 - 1299
(2007/10/02)
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- CATALYTIC ACTIVATION OF PHENYLISOCYANATE BY Ti(bpy)3
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Ti(bpy)3 activates PhNCO catalytically toward cyclotrimerization and condensation with aliphatic aldehydes.An important step of such catalytic reactions is the head-to-tail reductive coupling of PhNCO.
- Flamini Alberto,Giuliani, Anna M.,Poli, Nicola
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p. 2169 - 2170
(2007/10/02)
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- Halogen Epoxides, 5. Mixed Halogenated 2,3-Dihalo-2,3-diethyloxiranes: Synthesis, Limits of Existence, and Reactions with AgBF4
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3-Chloroperbenzoic acid reacts with mixed 3,4-dihalo-3-hexenes (1) to give the corresponding 2,3-dihalooxiranes having F/Cl (2a)-, F/Br (2b)-, F/I (2c)-, and Cl/Br (2d)-substituents, however, not that having Cl/I (2e)-substituents.In 1:1-reactions with AgBF4, the epoxides 2a - d were selectively attacked at the respective higher halogen homologue by silver ions.The fluorinated epoxides 2a - c afforded high yields of 4,4-difluoro-3-hexanone (12a), while the Cl/Br-epoxide 2d provided 4-chloro-4-fluoro-3-hexanone (12d) as the major product.
- Spraul, Manfred,Griesbaum, Karl
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p. 2641 - 2652
(2007/10/02)
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- Insertion of Carbon Monoxide into Nickel-Alkyl Bonds of Monoalkyl- and Dialkylnickel(II) Complexes, NiR(Y)L2 and NiR2L2. Preparation of Ni(COR)(Y)L2 from NiR(Y)L2 and Selective Formation of Ketone, Diketone, and Aldehyde from NiR2L2
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Reactions of monoalkylnickel(II) complexes, NiR(Y)L2 (R=CH3, C2H5; Y=Cl, suc(succinimido), pht(phthalimido), OC6H4-p-CN; L=1/2 bpy (2,2'-bipyridine), PEt3 (triethylphosphine)), with CO afford monoacylnickel(II) complexes, Ni(COR)(Y)L2, which are characterized by elemental analysis and spectroscopies (IR and NMR).Reactions of the acylnickel(II) complexes with alcohols and aniline give the corresponding esters and amides, respectively.Exposure of Ni(COR)(Y)L2 to dry air leads to oxidation of RCO to a RCOO ligand giving a complex formulated as NI(OCOR)(Y)L2.Reactions of dimethylnickel(II) complexes, Ni(CH3)2L2 (L=1/2 bpy, PEt3, 1/2dpe (1,2-bis(diphenylphosphino)ethane, 1/2 dpp (1,3-bis(diphenylphosphino)propane), with carbon monoxide afford acetone and/or 2,3-butanedione in medium to high yields, the acetone/2,3-butanedione ratio varying with the ligand L, reaction temperature, and additives such as maleic anhydride and triphenylphosphine.Generally the acetone/2,3-butanedione ratio decreases with increase in thermal stabilities of Ni(CH3)2L2.Ni(C2H5)2(bpy) and Ni(n-C3H7)2(bpy) give 3-pentanone and 4-heptanone, respectively, on treating them with CO, whereas Ni(C2H5)2(dpe) produces C2H5CHO and C2H4.
- Yamamoto, Takakazu,Kohara, Teiji,Yamamoto, Akio
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p. 2161 - 2168
(2007/10/02)
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