- Reduction of benzoyl tributylphosphonium chlorides by samarium diiodide as a novel access to 4-benzoylbenzaldehydes
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Addition of samarium diiodide to a well-stirred THF solution of benzoyl tributylphosphonium chlorides generated in situ from benzoyl chlorides and tributylphosphine at -40 °C gave 4-benzoylbenzaldehydes as predominant products from benzoyl chlorides without para-substituents, while benzoyl chloride bearing p-methyl or chloro groups was exclusively converted into the corresponding α-diketone.
- Maeda,Huang,Hino,Yamauchi,Ohmori
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- Dendrimer-like core cross-linked micelle stabilized ultra-small gold nanoclusters as a robust catalyst for aerobic oxidation of α-hydroxy ketones in water
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As one of the most general and promising stabilizers, dendrimers have been widely used to prepare ultra-small gold nanoclusters. However, the complex synthesis of dendrimers hinders the further application of protected nanoclusters. Here we report a facile strategy to prepare an alternative material via core cross-linking of self-assembled micelles. The resulting dendrimer-like core cross-linked micelles (DCCMs) retain the main characteristics of dendrimers and avoid complex chemical synthesis. As expected, the DCCMs could easily encapsulate gold nanoparticles within their cores. The ultra-small clusters of Au5 were prepared without the participation of external reductants. Importantly, the DCCM stabilized noble gold clusters furnish excellent catalytic activity and perfect reusability for aerobic oxidation of α-hydroxy ketones in water. Only in open air the oxidation could be repeated up to 48 times with negligible turn-over frequency change. The total turnover number (TON) of the reaction reached unexpectedly >48 000, the highest TON for metal catalysed oxidation of hydroxy ketones so far. The further mechanism study hints that the carboxylic group of substrates might be involved in the catalytic process. The simple catalyst preparation, the environmentally benign reaction conditions, and the excellent catalytic performance and durability make the novel DCCM protected gold nanocluster a green catalyst.
- Yu, Yangyang,Lin, Chenlu,Li, Bing,Zhao, Pengxiang,Zhang, Shiyong
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- Synthesis of α-Ketoimidoyl Fluorides via Geminal Fluorine-Promoted Azide Rearrangement
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Despite the promising synthetic potential, the utilization of imidoyl fluorides has been hampered by the lack of broadly applicable preparative methods. Herein, bench-stable α-ketoimidoyl fluorides were synthesized from geminal chlorofluorides through tandem azidation/rearrangement under mild conditions. The efficiency was consistently high, regardless of the steric and electronic environments. The synthetic utility of the α-ketoimidoyl fluoride was also demonstrated. Furthermore, the remarkable accelerating effect of the geminal fluorine substituent was identified and rationalized by density functional theory calculation.
- Kim, Ha Eun,Choi, Jun-Ho,Chung, Won-Jin
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p. 8810 - 8815
(2021/11/20)
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- Catalyst-Free and Transition-Metal-Free Approach to 1,2-Diketones via Aerobic Alkyne Oxidation
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A catalyst-free and transition-metal-free method for the synthesis of 1,2-diketones from aerobic alkyne oxidation was reported. The oxidation of various internal alkynes, especially more challenging aryl-alkyl acetylenes, proceeded smoothly with inexpensive, easily handled, and commercially available potassium persulfate and an ambient air balloon, achieving the corresponding 1,2-diketones with up to 85% yields. Meanwhile, mechanistic studies indicated a radical process, and the two oxygen atoms in the 1,2-diketons were most likely from persulfate salts and molecular oxygen, respectively, rather than water.
- Shen, Duyi,Wang, Hongyan,Zheng, Yanan,Zhu, Xinjing,Gong, Peiwei,Wang, Bin,You, Jinmao,Zhao, Yulei,Chao, Mianran
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p. 5354 - 5361
(2021/05/05)
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- Conversion of alkynes into 1,2-diketones using HFIP as sacrificial hydrogen donor and DMSO as dihydroxylating agent
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A metal-free and hypervalent iodine free conversion of internal alkynes into 1,2-diketo compounds has been described. The efficacy of the present protocol rely on the use of HFIP (1,1,1,3,3,3-Hexafluoro-2-propanol) as reducing agent of alkynes and DMSO as dihydroxylating agent of olefins to acquire the desired chemical transformations. The obtained 1,2-diketones were further transformed into useful derivatives.
- Gujjarappa, Raghuram,Vodnala, Nagaraju,Putta,Ganga Reddy, Velma,Malakar, Chandi C.
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supporting information
(2020/01/21)
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- Substituent Effect in the Synthesis of α,α-Dibromoketones, 1,2-Dibromalkenes, and 1,2-Diketones from the Reaction of Alkynes and Dibromoisocyanuric Acid
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Internal alkynes reacted with dibromoisocyanuric acid/H2O to afford α,α-dibromoketone and 1,2-diketone derivatives. Diarylalkynes with activating groups provided 1,2-diketone derivatives as the major products, whereas diarylalkynes with a non-activating group or alkylarylalkynes gave α,α-dibromoketone derivatives as the major products. In addition, diarylalkynes with deactivating groups provided 1,2-dibromoalkenes. The reaction was conducted at room temperature and showed good yields in most cases. Reaction pathways have been proposed on the basis of experimental observations and density functional theory (DFT) calculations. (Figure presented.).
- Cho, Eunjeong,Jayaraman, Aravindan,Lee, Junseong,Ko, Kyoung Chul,Lee, Sunwoo
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p. 1846 - 1858
(2019/03/07)
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- Synthesis of a new class of cationic Pd(II) complexes with 1,2,3-triazol-5-ylidene ligand and their catalytic application in the conversion of internal alkynes to 1,2-diketones
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A new class of cationic Pd(II) complexes of the type [Pd(Tz)(Cl)(bipy)]+Cl? and [Pd (Tz)(Cl)(phen)]+Cl? (Tz = 1,4-diaryl-3-methyl-1,2,3-triazol-5-ylidene, bipy = 2,2′-bipyridine and phen = 1,10-phenanthroline) with various wing tip groups were synthesized from the corresponding 1,2,3-triazolium iodide via the corresponding chloro bridged dinuclear complexes [(Tz)(Cl)Pd(μ-Cl)2Pd(Cl)(Tz)]. The synthesized cationic complexes were screened for their catalytic activity of hydration of alkynes and found to be excellent towards the selective conversion of internal alkynes to the corresponding 1,2-diketones in good yields. A plausible mechanism was proposed for this conversion.
- Shaik, Jeelani Basha,Ramkumar, Venkatachalam,Sankararaman, Sethuraman
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supporting information
p. 1 - 8
(2018/02/19)
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- NaBrO3/bmim[HSO4]: a versatile system for the selective oxidation of 1,2-diols, α-hydroxyketones, and alcohols
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Abstract: Sodium bromate with bmim[HSO4] has been found to be an excellent oxidizing agent in aqueous medium. NaBrO3:bmim[HSO4] oxidized 1,2-diols, α-hydroxyketones, and alcohols to the corresponding carbonyl compounds in excellent yields. This method offers advantages such as low cost reagents, aqueous reaction conditions, moderate temperatures and short reaction times and hence environmentally benign reaction. Moreover, the ionic liquid bmim[HSO4] could be recycled for at least three times without loss of significant activity. Graphical abstract: [Figure not available: see fulltext.]
- Khurana, Jitender M.,Lumb, Anshika,Chaudhary, Ankita
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p. 381 - 386
(2017/02/10)
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- Copper-catalyzed TEMPO oxidative cleavage of 1,3-diketones and β-keto esters for the synthesis of 1,2-diketones and α-keto esters
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A copper-catalyzed efficient and practical method has been developed for the synthesis of 1,2-diketones and α-keto esters. TEMPO was used as a radical initiator and scavenger, oxidizing the cleavage of α-methylene of 1,3-diketones and β-keto esters to form 1,2-diketones and α-keto esters. This method provided a general way for the formation of 1,2-dicarbonyl compounds.
- Zhou, Peng-Jun,Li, Cheng-Kun,Zhou, Shao-Fang,Shoberu, Adedamola,Zou, Jian-Ping
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p. 2629 - 2637
(2017/04/03)
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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 0029
(2016/10/08)
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- Lanthanum triflate-catalyzed rapid oxidation of secondary alcohols using hydrogen peroxide urea adduct (UHP) in ionic liquid
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A convenient and efficient protocol for the oxidation of secondary hydroxyl group to ketone using hydrogen peroxide-urea adduct and catalytic (CF 3SO3)3La in ionic liquid has been developed. A number of 1,2-diols, -hydroxyketones, and other aromatic and aliphatic secondary alcohols have been successfully oxidized to the corresponding ketones using this protocol in good yields and short reaction times. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Saluja, Pooja,Magoo, Devanshi,Khurana, Jitender M.
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supporting information
p. 800 - 806
(2014/03/21)
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- Synthesis of new chiral keto alcohols by baker's yeast
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Fourteen chiral α- and β-keto alcohols 2a-2r were synthesized by the asymmetric reduction of their corresponding diketones 1a-1r via baker's yeast. In addition, ten corresponding racemic α-keto alcohols were synthesized by the benzoin condensation of their corresponding aldehydes, which were used for the determination of the ee values through their chiral resolution on chiral HPLC. Amongst the 15 diketones, 1j and chiral α-keto alcohols 2i, 2j and chiral β-keto alcohol 2r are novel compounds. Six keto alcohols 2b, 2c, 2d, 2f, 2h and 2p were synthesized by baker's yeast for the first time. There are some studies in the literature where baker's yeast was applied to the diketones 1a, 1g, 1e, 1k and 1n under various conditions different to those reported herein. The yields and the ee values of these studies were not as high as ours. All of the keto alcohols synthesized were characterized by IR, NMR (1H and 13C), and MS. The relationship between the structure of the diketone and the yield, diastereoselectivity and enantiomeric excess is also discussed.
- Yildiz, Tuelay,Canta, Nurguel,Yusufoglu, Ayse
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p. 340 - 347
(2014/04/03)
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- Copper-catalyzed direct synthesis of diaryl 1,2-diketones from Aryl iodides and propiolic acids
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Benzil derivatives such as diaryl 1,2-diketones are synthesized via the direct decarboxylative coupling reaction of aryl propiolic acids and their oxidation. The optimized conditions are that the reaction of aryl propiolic acids and aryl iodides is conducted at 140°C for 6 h in the presence of 10 mol % CuI/Cu(OTf)2 and Cs2CO3, after which HI (aq) is added and further reacted. The method shows good functional group tolerance toward ester, aldehyde, cyano, and nitro groups. In addition, symmetrical diaryl 1,2-diketones are obtained from aryl iodides and propiolic acid in the presence of palladium and copper catalysts.
- Min, Hongkeun,Palani, Thiruvengadam,Park, Kyungho,Hwang, Jinil,Lee, Sunwoo
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p. 6279 - 6285
(2014/07/21)
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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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- Metal-free oxidation of α-hydroxy ketones to 1,2-diketones catalyzed by mesoporous carbon nitride with visible light
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As a photocatalyst, mesoporous carbon nitride (mpg-C3N 4) shows higher photocatalytic activities in organic synthesis. Herein we report an mpg-C3N4-catalyzed oxidation of α-hydroxy ketones to synthesize 1,2-diketones using visible light. This transformation represents a green and highly efficient synthetic route to synthesize 1,2-diketones for which catalytic approaches are scarce.
- Zheng, Zhishuo,Zhou, Xiaosong
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p. 1683 - 1686,4
(2020/08/31)
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- An efficient palladium-catalyzed synthesis of benzils from aryl bromides: Vinylene carbonate as a synthetic equivalent of glyoxal
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An expedient synthetic procedure of benzil derivatives from aryl bromides was developed using vinylene carbonate as a glyoxal equivalent in a palladium-catalyzed reaction. The reaction involved a sequential diarylation of vinylene carbonate to form 4,5-diaryl-1,3-dioxol-2-one, ring-opening to benzoin derivative, and an oxidation process.
- Kim, Ko Hoon,Park, Bo Ram,Lim, Jin Woo,Kim, Jae Nyoung
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experimental part
p. 3463 - 3466
(2011/06/27)
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- Chiral Zn-catalyzed aerobic oxidative kinetic resolution of α-hydroxy ketones
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The aerobic oxidative kinetic resolution of racemic α-hydroxy ketones was accomplished using a chiral Zn-quinine complex as the catalyst in the presence of molecular oxygen. The resulting optimized reaction conditions were applied to resolute different types of racemic α-hydroxy ketones and a maximum of 9.2 selectivity (s) was obtained with 88% ee for the recovered α-hydroxy ketone.
- Muthupandi, Pandi,Sekar, Govindasamy
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experimental part
p. 512 - 517
(2011/06/17)
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- Zinc-catalyzed aerobic oxidation of benzoins and its extension to enantioselective oxidation
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Zn(II)-DABCO complex is used as an efficient catalyst for the aerobic oxidation of benzoins to benzils in the presence of molecular oxygen. Usage of chiral zinc complex as catalyst resulted in enantioselective oxidative kinetic resolution of racemic benzoin to yield enantiomerically enriched benzoins.
- Muthupandi, Pandi,Sekar, Govindasamy
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supporting information; experimental part
p. 692 - 695
(2011/03/21)
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- Optical resolution of (±)-1,2-bis(2-methylphenyl)ethylene-1,2- diamine as a chiral framework for 2-iminoimidazolidine with 2-methylphenyl pendant and the guanidine-catalyzed asymmetric michael reaction of tert-butyl diphenyliminoacetate and ethyl acrylate
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(Chemical Equation Presented) (±)-1,2-Bis(2-methylphenyl)ethylene-1, 2-diamine, prepared from benzil and ammonium acetate, was optically resolved as a chiral framework for 2-(1-benzyl-2-hydroxyethyl)imino-1,3- dimethylimidazolidine with 2-methylphenyl pen
- Ryoda, Akemi,Yajima, Nana,Haga, Toyokazu,Kumamoto, Takuya,Nakanishi, Waka,Kawahata, Masatoshi,Yamaguchi, Kentaro,Ishikawa, Tsutomu
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p. 133 - 141
(2008/09/17)
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- From enolates to anthraquinones
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A series of highly reactive cyclopentadienones were prepared in situ from the corresponding hydroxycyclopent-2-enones and trapped with a variety of quinones. Reaction of 1,4-naphthoquinone with 4-hydroxy-3,4-diphenyl-cyclopent- 2-enone afforded 2,3-diphenylanthraquinone, whereas reaction of benzoquinone with this same cyclopentadienone precursor yielded a mixture of 6,7-dipheny 1-1,4-naphthoquinone and 2,3,6,7-tetraphenylanthraquinone. A number of other 2,3-diarylanthraquinones were likewise prepared in moderate yields from the reaction of 1,4-naphthoquinone with the appropriate 4-hydroxy-3,4- diarylcyclopent-2-enones. This method appears to be generally applicable to the synthesis of anthraquinone derivatives substituted at the 2- and 3-positions from inexpensive starting materials.
- Bailey, David,Murphy, Jeffrey N.,Williams, Vance E.
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p. 659 - 666
(2007/10/03)
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- Electrochemical oxidation of benzoins to benzils in the presence of a catalytic amount of KI in basic media
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Various benzoins were transformed into the corresponding benzils via an electrochemical method. Although the strategy of oxidizing benzoins to the corresponding benzils is generally chosen depending on the nature of the aromatic moiety, the electrochemical technique reported herein allows oxidation that is widely applicable, and without the use of environmentally undesirable oxidants.
- Okimoto, Mitsuhiro,Takahashi, Yukio,Nagata, Yuji,Sasaki, Gaku,Numata, Kaori
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p. 705 - 707
(2007/10/03)
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- A novel decyanogenative coupling of α-cyanoimines mediated by samarium. A facile route to α-diketimines
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Conversion of α-cyanoimines 1 into α-diketimines 2 has been achieved successfully by using samarium diiodide in dry tetrahydrofuran in high yields without formation of anilinoanil 3, 1,2-diamines 4 or anilides 5.
- Thakur, Ashim J.,Prajapati, Dipak,Sandhu, Jagir S.
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p. 102 - 103
(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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- Indium-mediated reductive coupling of acyl cyanides: A convenient synthesis of 1,2-diketones
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The indium-mediated reductive coupling of acyl cyanides afforded the corresponding 1,2-diketones in moderate to good yields under neutral and mild conditions. (C) 2000 Elsevier Science Ltd.
- Baek,Lee,Yoo,Ko,Kim,Kim
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p. 8097 - 8099
(2007/10/03)
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- Synthesis of highly hindered 1,2-diaryl diketones and of cis- and trans-1,2-diacetoxy-1,2-bis(aryl)ethenes
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Highly hindered 1,2-diaryl diketones can be synthesized in good yields by the reaction of 1-aryllithium with CO in THF solution at atmospheric pressure; preparation of cis- and trans-1,2-diacetoxy-1,2-bis(Mes)ethene can be also afforded by a similar procedure and further quenching with Ac2O.
- Nudelman, Norma,Schulz, Hernan
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p. 422 - 423
(2007/10/03)
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- A Direct Access to α-Diones from Oxalyl Chloride
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Cross-coupling reactions of oxalyl chloride with organocopper reagents, derived from Grignard reagents, cuprous bromide, and lithium bromide, provide a simple and straightforward method for the synthesis of symmetrical α-diones in very good yields.
- Babudri, Francesco,Fiandanese, Vito,Marchese, Giuseppe,Punzi, Angela
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p. 7305 - 7308
(2007/10/02)
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- Synthesis of Symmetrical Diaryl 1,2-Diketones from Grignard Reagents and 1,1'-Oxalylimidazole
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Symmetrical diaryl 1,2-diketones (α-diketones) are obtained in reasonably good yields when readily accessible 1,1'-oxalylimidazole is treated with two equivalents of an aryl Grignard reagent.
- Mitchell, Reginald H.,Iyer, Vivekanantan S.
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p. 3683 - 3686
(2007/10/02)
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- REDUCTIVE COUPLING OF BENZOIC ACID HALIDES AND ESTERS USING LOW-VALENT TITANIUM
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The reductive coupling of (substituted) benzoic acid chlorides and esters is achieved using low-valent titanium, generated from TiCl3 and LiAlH4.Both acid chlorides and esters seem to follow the same two reaction pathways: one path via tolanes to stilbenes, the other via benzils to complex mixtures of products arising from reduction and further coupling reactions.Although the exact product balance depends upon the reaction conditions the major product is (substituted) cis-stilbene.
- Dang, Y.,Geise, H. J.
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p. 375 - 380
(2007/10/02)
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- DI(ACYLOXY)IODOARENES IN ORGANIC SYNTHESIS. III. REACTION OF DIARYLACETYLENES WITH BIS(TRIFLUOROACETOXY)IODOBENZENE
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Bis(trifluoroacetoxy)iodobenzene in chloroform oxidizes diarylacetylenes containing electron-donating and not very strong electron-withdrawing substituents to the corresponding benzils with high yields.The reaction probably takes place through the intermediate formation of vinyl- and alkyliodonium salts.Benzoin is oxidized to benzil.
- Vasil'eva, V. P.,Khalfina, I. L.,Karpitskaya, L. G.,Merkushev, E. B.
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p. 1967 - 1969
(2007/10/02)
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- Preparation and antiinflammatory activity of some nonacidic trisubstituted imidazoles
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A number of trisubstituted imidazoles were made and several found to be potent antiinflammatory agents when examined in the carrageenan rat paw edema test. The antiinflammatory activity of these compounds is retained in adrenalectomized rats. Unlike many previously reported antiinflammatory agents, these compounds are extremely weak acids pK[a] ≥ 11) and are therefore not ionized at physiological pH. One compound, 4,5 bis (4 methoxyphenyl) 2 trifluoromethylimidazole (flumizole), is more potent than indometacin in the rat paw edema test and, in contrast to some related compounds, does not cause photosensitization in mice.
- Lombardino,Wiseman
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p. 1182 - 1188
(2007/10/04)
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