- Catalytic Highly Regioselective C-H Oxygenation Using Water as the Oxygen Source: Preparation of 17O/18O-Isotope-Labeled Compounds
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We found that the oxygen atom of water is activated to iodosylbenzene derivatives via reversible hydrolysis of PhI(OOCR)2 and can be used to the oxygen source for ruthenium(bpga)-catalyzed site-selective C-H oxygenation. Ru(bpga)/PhI(OOCR)2/H2O system, sterically less bulky methinic and methylenic C-H bonds in various compounds can be converted to desired oxygen functional groups in a site-selective manner. Using this method, oxygen-isotope labeled compounds such as d-[3-17O/18O]-mannose can be prepared in a multigram scale.
- Doiuchi, Daiki,Uchida, Tatsuya
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supporting information
p. 7301 - 7305
(2021/10/01)
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- 1,2-Dibromoethane and KI mediated α-acyloxylation of ketones with carboxylic acids
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The 1,2-dibromoethane- and KI-mediated α-acyloxylation of ketones is reported in moderate to good yield without the use of transition metals and strong oxidants. Various acids are well tolerated with wide functional group compatibility. An 1,2-dibromoethane- and KI-catalysed reaction mechanism is proposed based on the results of control experiments.
- Wang, Xujie,Li, Gangsheng,Yang, Yanan,Jiang, Jianshuang,Feng, Ziming,Zhang, Peicheng
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supporting information
p. 711 - 714
(2019/09/30)
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- Microwave-Enhanced Coupling of Carboxylic Acids with Liquid Ketones and Cyclic Ethers Using Tetrabutylammonium Iodide/ t-Butyl Hydroperoxide
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The oxidative coupling of carboxylic acids with liquid ketones and cyclic ethers has been accomplished in minutes using t-butyl hydroperoxide in the presence of tetrabutylammonium iodide under microwave irradiation in the absence of a solvent. In addition to drastically shortening the reaction times, the use of microwaves resulted, in general, in yields equal to or higher than those obtained by conventional heating.
- Macías-Benítez, Pablo,Moreno-Dorado, F. Javier,Guerra, Francisco M.
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p. 6027 - 6043
(2020/05/22)
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- Catalytic Enantioselective α-Ketol Rearrangement
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A highly enantioselective α-ketol rearrangement has been developed. In the presence of a chiral Cu-bisoxazoline complex, achiral β-hydroxy-α-dicarbonyls were isomerized to chiral α-hydroxy-β-dicarbonyls and their bicyclic derivatives in excellent yields and enantioselectivities. Enantioenriched 2-acyl-2-hydroxy cyclohexan-1-ones, dihydroxyhexahydrobenzofuranones, and dihydroxyhexahydro-cycloheptafuranones, with up to three stereocenters, were readily prepared from achiral starting materials in one operation. The reaction is applicable to the desymmetrization of meso substrates and kinetic resolution of racemic alcohols.
- Wu, Hua,Andres, Rémi,Wang, Qian,Zhu, Jieping
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p. 499 - 503
(2018/12/13)
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- C–O bond formation via oxidative-coupling pathway in eutectic mixture of choline chloride/urea as a green solvent
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C–O bond formation between terminal alkenes/benzyl alcohols as an arylcarboxy surrogate and carbonyl compounds in a biodegradable deep eutectic solvent (DES) based on choline chloride and urea was performed. By employment of TBAI as catalyst and TBHP as oxidant, various derivatives of carbonyl compounds were benzylated in α position in good to high yield at 90 °C. Moreover, α-oxybenzoylation of diethyl malonate with carboxylic acids was performed in the above-mentioned DES by employment of NaI as the catalyst and TBHP as the oxidant at 60 °C.
- Saberi, Dariush,Manouchehri, Neda,Niknam, Khodabakhsh
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p. 680 - 687
(2019/01/03)
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- Copper-catalyzed α-C-H acyloxylation of carbonyl compounds with terminal alkynes
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Herein, a copper/TBHP catalyst system for the α-C-H acyloxylation of carbonyl compounds is developed using terminal alkynes as the acyloxy source. A variety of carbonyl compounds and terminal alkynes are tolerated in this reaction. In addition, its possible mechanism is proposed.
- Li, Jiao,Yang, Zan,Yang, Tao,Yi, Jianmin,Zhou, Congshan
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supporting information
p. 1581 - 1584
(2018/02/09)
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- Method for preparing alpha-acyloxy ketone compound from terminal alkyne compounds
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The invention provides a method for efficiently synthesizing an alpha-acyloxy ketone compound containing different substitute functional groups. According to the method, acetylacetone copper is taken as a reaction catalyst, t-butylhydroperoxide is taken as an antioxidant, ketone compounds and terminal alkyne compounds are taken as reaction substrates, and an organic solvent is added into a reaction system. The method has the advantages that the catalyst is cheap and easily available; reaction conditions are mild, safe and reliable; and the productivity of an obtained target product is relatively high. According to the method, the problem that a traditional alpha-acyloxylation reaction system is single is solved, and a novel acyloxylation reagent is provided; and the method has good industrial application prospects.
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Paragraph 0042
(2017/09/01)
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- Synthesis of α-oxygenated ketones and substituted catechols via the rearrangement of N-enoxy- and N-aryloxyphthalimides
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A common approach to the synthesis of α-oxygenated carbonyl compounds and catechols is the treatment of a carbonyl compound or a phenol with an electrophilic oxygen source. As an alternative approach to these important structures, formal [3,3]-rearrangements of N-enoxyphthalimides, N-enoxyisoindolinones, and N-aryloxyphthalimides have been explored. When used in combination with an initial Chan-Lam coupling, these transformations facilitate the dioxygenation of alkenylboronic acids for the synthesis of α-oxygenated ketones and the dioxygenation of arylboronic acids for the synthesis of catechols. The rearrangements of N-enoxyisoindolinones have also been shown to be diastereoselective.
- Kroc, Michelle A.,Patil, Aditi,Carlos, Anthony,Ballantine, Josiah,Aguilar, Stephanie,Mo, Dong-Liang,Wang, Heng-Yen,Mueller, Daniel S.,Wink, Donald J.,Anderson, Laura L.
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p. 4125 - 4137
(2017/06/29)
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- Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
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Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including alkenyl halides, sulfides, triflates, and phosphonates and provides a mild and practical alternative to the Tamao-Fleming oxidation of vinylsilanes and the Arndt-Eistert homologation.
- Ma, Xiaoshen,Herzon, Seth B.
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p. 8673 - 8695
(2016/10/17)
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- One-pot synthesis of α-acyloxycarbonyl compounds via oxidative decarboxylation coupling reaction of α-oxo carboxylic acids with carbonyl compounds
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With tetrabutylammonium iodide (TBAI) as the catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant, a simple metal-free protocol has been developed for the synthesis of α-acyloxycarbonyl compounds from carbonyl compounds and α-oxo carboxylic acids via decarboxylative coupling reaction. The target products could be obtained in moderate to high yields.
- Chang, Li-Ming,Yuan, Gao-Qing
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p. 7003 - 7007
(2016/10/13)
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- Bu4NI-Catalyzed α-Oxyacylation of Carbonyl Compounds with Toluene Derivatives
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A TBAI (tetrabutylammonium iodide)-catalyzed direct α-oxyacylation of carbonyl compounds from readily available toluene derivatives has been developed. The distinguished features of this metal-free protocol include the employment of simple starting material, a wide carbonyl compound scope, and mild reaction conditions.
- Li, Chengliang,Jin, Tao,Zhang, Xinglu,Li, Chunju,Jia, Xueshun,Li, Jian
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supporting information
p. 1916 - 1919
(2016/05/19)
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- Sequential [3,3]-Sigmatropic Rearrangement/Nucleophilic Arylation of N -(Benzoyloxy)enamides towards the Preparation of Cyclic β-Aryl-β-amino Alcohols
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A new method has been developed for the efficient synthesis of cyclic β-aryl-β-amino alcohol derivatives bearing a tetrasubstituted carbon center via the [3,3]-sigmatropic rearrangement of N-(benzoyl oxy)enamides followed by nucleophilic arylation reactio
- Sato, Shohei,Takeda, Norihiko,Ueda, Masafumi,Miyata, Okiko
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p. 882 - 892
(2016/03/15)
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- Fungicidal heterocyclic aromatic amides and their compositions, methods of use and preparation
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Heterocyclic aromatic amides having a hydroxy group adjacent to the amide functionality are useful as antifungal agents, particularly for plants.
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- I2-catalyzed regioselective oxo- and hydroxy-acyloxylation of alkenes and enol ethers: A facile access to α-acyloxyketones, esters, and diol derivatives
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I2-catalyzed oxo-acyloxylation of alkenes and enol ethers with carboxylic acids providing for the high yield synthesis of α-acyloxyketones and esters is described. This unprecedented regioselective oxidative process employs TBHP and Et3/s
- Reddi, Rambabu N.,Prasad, Pragati K.,Sudalai, Arumugam
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supporting information
p. 5674 - 5677
(2015/02/19)
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- Preparation of α-oxygenated ketones by the dioxygenation of alkenyl boronic acids
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Two in two: Dioxygenation of alkenyl boronic acids has been achieved with N-hydroxyphthalimide. The two-step process involves etherification of an alkenyl boronic acid with N-hydroxyphthalimide followed by a [3,3] rearrangement. The dioxygenated product can then be hydrolyzed to form either the corresponding α-hydroxy ketone or the α-benzoyloxy ketone. Copyright
- Patil, Aditi S.,Mo, Dong-Liang,Wang, Heng-Yen,Mueller, Daniel S.,Anderson, Laura L.
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supporting information; experimental part
p. 7799 - 7803
(2012/09/08)
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- Asymmetric α-oxyacylation of cyclic ketones
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Reaction of cyclic ketones with chiral N-alkyl-O-acyl hydroxylamines leads to the corresponding α-oxyacylated carbonyl compound in up to 89% ee. The levels of asymmetric induction were influenced by solvent polarity, acid strength and, to a lesser extent,
- Smithen, Deborah A.,Mathews, Christopher J.,Tomkinson, Nicholas C.O.
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p. 3756 - 3762
(2012/06/01)
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- Manganese-catalyzed direct oxidation of methyl ethers to ketones
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Direct C-H oxidation of alkyl ethers into ketones was achieved using 0.1 mol % of MnCl2 and 4, 4′, 4″-tri(tert-butyl)-2, 2′:6′, 2″-terpyridine (tBu-terpy) in the presence of mCPBA. Conversion of methyl ethers into ketones was particularly efficient and chemoselective. Electron-deficient oxygen functionalities survived under the reaction conditions. The present method broadens the utility of methyl ethers as stable protective groups for hydroxy functionalities and as precursors to carbonyl compounds. (Chemical equation presented).
- Kamijo, Shin,Amaoka, Yuuki,Inoue, Masayuki
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supporting information; experimental part
p. 486 - 489
(2010/09/04)
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- Unified oxidation protocol for the synthesis of carbonyl compounds using a manganese catalyst
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We have developed a unified protocol for the oxidation of ethers, benzylic compounds, and alcohols to carbonyl compounds. The protocol uses catalytic amounts of manganese(II) chloride tetrahydrate and tri(t-butyl)-2,2':6',2Prime;- terpyridine in combination with a stoichiometric amount of either m-chloroperbenzoic acid (MCPBA) or potassium hydrogen peroxysulfate (KHSO 5). A reagent system consisting of the Mn catalyst and MCPBA permitted the chemoselective sp3 C-H oxidation of alkyl ethers and benzylic compounds to generate the corresponding ketones. Alternatively, the water-soluble inorganic salt KHSO5 in combination with the Mn catalyst was used to oxidize alcohols to ketones or carboxylic acids. Importantly, the Mn catalyst/KHSO5 system eliminates technical difficulties associated with the isolation of carboxylic acid products. All the oxidations presented in this feature article proceed at sup-ambient temperature in an aerobic atmosphere, and can therefore be used in practical syntheses of complex organic molecules. Georg Thieme Verlag Stuttgart · New York.
- Kamijo, Shin,Amaoka, Yuuki,Inoue, Masayuki
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experimental part
p. 2475 - 2489
(2010/09/06)
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- Highly enantioselective organocatalytic oxidative kinetic resolution of secondary alcohols using chirally Modified AZADOs
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A highly enantioselective organocatalytic oxidative kinetic resolution (OKR) of racemic secondary alcohols has been accomplished using asymmetric organocatalysis. A panel of chirally modified 2-azaadamantane N-oxyls (AZADOs) exhibit superior catalytic act
- Tomizawa, Masaki,Shibuya, Masatoshi,Iwabuchi, Yoshiharu
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supporting information; scheme or table
p. 1828 - 1831
(2009/09/06)
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- A general method for the α-acyloxylation of carbonyl compounds
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(Chemical Equation Presented) A simple, one-pot method for the α-acyloxylation of carbonyl compounds that proceeds at room temperature in the presence of both moisture and air has been developed. Treatment of a variety of aldehydes and both cyclic and acy
- Beshara, Cory S.,Hall, Adrian,Jenkins, Robert L.,Jones, Kerri L.,Jones, Teyrnon C.,Killeen, Niall M.,Taylor, Paul H.,Thomas, Stephen P.,Tomkinson, Nicholas C. O.
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p. 5729 - 5732
(2007/10/03)
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- Oxidation of bicyclic oxazolines: Applications to glycomimetics and novel saccharide derivatives
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A general procedure is reported for the oxidation of substituted oxazolines to α-acyloxyketoximes and the derived α-acyloxyketones. In the case of oxazolines derived from 2-acetamido-2-deoxyhexoses, the resulting 2-oximinoesters can be converted to 2-nitr
- Clark, Matthew A,Wang, Qunzhao,Ganem, Bruce
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p. 347 - 349
(2007/10/03)
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- Fungicidal heterocyclic aromatic amides and their compositions, methods of use and preparation
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A compound having the following formula: wherein R3and M are defined herein, and processes therewith.
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- Acyloxylation of 1-methoxycyclohex-1-ene and other enol ethers with dimethyl peroxydicarbonate
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Acyloxylation of different types of enol ethers (derived from aldehydes and ketones) by dimethyl peroxydicarbonate (DPDC) results in either addition to the double bond or in a formal replacement of an allylic hydrogen by a methoxycarbonyloxy group forming vicinal oxygenated hydrocarbons. 1,3-Oxygenated products via monoacyloxylation could not be observed. The results are compared with copper(I)-catalyzed acyloxylations of 1-methoxycyclohex-1-ene (1a) by means of tert-butyl peroxycarboxylates 2a, b.
- Schank,Beck,Pistorius,Rapold
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p. 964 - 968
(2007/10/02)
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- Fluoride Ion Catalyzed Reduction of Aldehydes and Ketones with Hydrosilanes. Synthetic and Mechanistic Aspects and an Application to the Threo-Directed Reduction of α-Substituted Alkanones
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Reduction of aldehydes and ketones with hydrosilanes proceeded in the presence of a catalytic amount of tetrabutylammonium fluoride or tris(diethylamino)sulfonium difluorotrimethylsilicate in aprotic polar solvents under mild conditions.A significant isotope effect (kH/kD = 1.50) was observed in competitive reduction of acetophenone with HSiMe2Ph and DSiMe2Ph.The reaction was of first order in the concentration of an aprotic polar solvent HMPA.Reduction of 2-methylcyclohexanone gave cis-2-methylcyclohexanol with selectivities up to 95percent.The kinetic and stereochemical results suggest that a hexavalent fluorosilicate - is involved. α-Alkoxy (acyloxy or dimethylamino) ketones were transformed to threo alcohols in high diastereoselectivities.The reduction was also applied to α-methyl-β-keto amides, RCOCH(MeCONR)2, to afford the corresponding threo alcohols in >98percent selectivity.The threo selectivity is explained in terms of the Felkin-Anh model in which interaction of carbonyl oxygen with a countercation is ideally suppressed.The threo-directed reduction was applied to (R)-1-phenyl-4-(2-tetrahydropyranyloxy)-1-penten-3-one and N-(2-benzoylpropanoyl)piperidine.The resulting threo alcohols were respectively converted into (2R,3S)-2,3-(cyclohexylidenedioxy)butanal, a key intermediate of daunosamine synthesis, and into a pharmacologically useful compound threo-N-(3-hydroxy-2-methyl-3-phenylpropyl)piperidine.
- Fujita, Makoto,Hiyama, Tamejiro
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p. 5405 - 5415
(2007/10/02)
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- Reaction of Enol Silyl Ethers with Silver Carboxylate-Iodine. Synthesis of α-Acyloxy Carbonyl Compounds
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The sequential treatment of enol silyl ethers with silver carboxylate-iodine (2:1) and then fluoride affords high yields of the corresponding α-acyloxy carbonyl compounds.Thus a wide range of variation is now possible for the acyloxy portion of the molecu
- Rubottom, George M.,Mott, Robert C.,Juve, Henrik D.
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p. 2717 - 2721
(2007/10/02)
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