- Selective oxidation of alcohols to carbonyl compounds mediated by fluorous-tagged TEMPO radicals
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Oxidation of primary, benzylic and secondary alcohols into their corresponding aldehydes and ketones with safe, inexpensive oxidants was achieved in good yields under mild conditions in the presence of catalytic amounts of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radicals bearing perfluoroalkyl substituents. These "fluorous-tagged" TEMPOs were readily isolated from the reaction products by liquid-liquid or solid-phase extraction, considerably simplifying the purification step. Their recyclability was strongly influenced by the nature of the oxidizing system. The best results were obtained using either [bis(acetoxy)iodo]benzene (BAIB) or aqueous NaOCl as the primary oxidants. Fluorous TEMPO 10 could be reused up to six times in the BAIB oxidation of 1-octanol with only minor loss of catalytic activity.
- Holczknecht, Orsolya,Cavazzini, Marco,Quici, Silvio,Shepperson, Ian,Pozzi, Gianluca
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- Experimental and computational study of a direct O2-coupled wacker oxidation: Water dependence in the absence of Cu salts
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The kinetics of the Pd[(-)-sparteine]Cl2 catalyzed oxidation of decene using oxygen as the sole oxidant have been studied in the absence of copper salts and high [Cl-]. Saturation kinetics are observed for [decene] as well as a third order dependence on [water]. A mechanism is proposed involving the dissociation of two chlorides and rate-limiting formation of a three-water hydrogen bridged network and subsequent oxypalladation as supported by computational studies.
- Anderson, Brian J.,Keith, John A.,Sigman, Matthew S.
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- Imidazolium Dichromate. A New Reagent for the Oxidation of Alcohols to Carbonyl Compounds
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Imidazolium dichromate, a stable yellow crystalline compound, is found to bee a mild selective reagent for the oxidation of allylic and benzylic alcohols to the corresponding carbonyl compounds.
- Kim, Sunggak,Lhim, Dong Chul
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- Triethylammonium fluorochromate - A new, mild, stable, and inexpensive chromium(VI) oxidant
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Triethylammonium fluorochromate was prepared and was used to quantitatively oxidize a number of organic substrates. Triethylammonium fluorochromate is a versatile reagent ensuring effective and selective oxidation of organic compounds, in particular of alcohols, under mild conditions.
- Ghammamy,Hashemzadeh,Mazareey
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- Nitrous oxide oxidation of secondary and benzylic alcohols using ruthenium complex catalyst
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Catalytic N2O oxidation of various secondary and benzylic alcohols using a ruthenium porphyrin complex is presented. Both secondary and benzylic alcohols were smoothly consumed to give the corresponding ketones and aldehydes in high yields. Nitrous oxide (N2O) is expected to be a new terminal oxidant producing only dinitrogen gas as the only by-product to provide a less wasteful process.
- Hashimoto, Kentaro,Kitaichi, Yasunori,Tanaka, Hirotaka,Ikeno, Taketo,Yamada, Tohru
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- Thiol-functionalized fructose-derived nanoporous carbon as a support for gold nanoparticles and its application for aerobic oxidation of alcohols in water
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Gold nanoparticles supported on thiol-functionalized fructose-derived nanoporous carbon (AuNPs@thiol-Fru-d-NPS) were found to be a simple bench-top, biocompatible, recyclable and selective catalytic system for the aerobic oxidation of various types of alcohols into their corresponding aldehydes and ketones at room temperature under the environmentally friendly conditions with excellent yields. Copyright
- Mahyari, Mojtaba,Shaabani, Ahmad,Behbahani, Mohammad,Bagheri, Akbar
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- Aerobic deprotection of monothioacetals catalyzed by trichlorooxyvanadium
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Monothioacetals are easily deprotected into carbonyls using a catalytic amount of trichlorooxyvanadium under an oxygen atmosphere.
- Kirihara, Masayuki,Ochiai, Yuta,Arai, Nobuka,Takizawa, Shinobu,Momose, Takefumi,Nemoto, Hideo
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- Deprotection of dithioacetals using the tantalum(V) chloride catalyzed oxidation of iodide ion by hydrogen peroxide
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Dithioacetals can be deprotected to afford carbonyl groups using the tantalum(V) chloride catalyzed oxidation of iodide ion by hydrogen peroxide under mild conditions.
- Kirihara, Masayuki,Harano, Aiko,Tsukiji, Hiroyuki,Takizawa, Ryu,Uchiyama, Tomoyuki,Hatano, Akihiko
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- Synthesis and catalytic activity of a fluorous-tagged TEMPO radical
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A fluorous-tagged TEMPO radical has been prepared and its catalytic activity in the chemoselective oxidation of alcohols to carbonyl compounds has been investigated. The new fluorous radical proved to be an efficient, selective and easily recoverable catalyst, which can be conveniently used in standard organic solvents and then isolated and recycled by fluorous liquid-liquid extraction.
- Pozzi, Gianluca,Cavazzini, Marco,Holczknecht, Orsolya,Quici, Silvio,Shepperson, Ian
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- A NEW PROCEDURE FOR DETHIOACETALIZATION
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A simple procedure has been developed for the conversion of thioacetals to the corresponding carbonyl compounds using the combination of phenyl dichlorophosphate, dimethylformamide and sodium iodide.
- Liu, Hsing-Jang,Wiszniewski, Virginia
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- Copper-catalyzed aerobic oxidation of alcohols under fluorous biphasic conditions
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A catalytic amount of perfluoroalkyl substituted bipyridine 1 (2 mol%), CuBr·Me2S (2 mol%) and TEMPO (3.5 mol%) allow the oxidation of various alcohols to aldehydes and ketones in a fluorous biphasic system of chlorobenzene and perfluorooctane directly with oxygen. The catalyst can be used for several reaction runs without a loss of reactivity. (C) 2000 Elsevier Science Ltd.
- Betzemeier, Bodo,Cavazzini, Marco,Quici, Silvio,Knochel, Paul
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- Hydroformylation of alkenes using heterogeneous catalyst prepared by intercalation of HRh(CO)(TPPTS)3 complex in hydrotalcite
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Intercalation of HRh(CO)(TPPTS)3 complex into the interlayer space of hydrotalcite was carried out to prepare an eco-friendly heterogeneous hydroformylation catalyst. Intercalated catalyst was characterized by 31P NMR, P-XRD, FT-IR, SEM and surface area measurements. Catalytic activity of intercalated catalyst [HT(3.5)-INT] was evaluated for hydroformylation of linear alkenes of varied carbon number from C5 to C13 as well as cyclic alkenes. Selectivity of the aldehydes was observed to decrease with increase in the carbon chain length of linear alkenes. Effect of reaction parameters on catalytic activity of intercalated catalyst was studied by varying the catalyst amount, 1-hexene concentration, reaction temperature, partial pressure of carbon monoxide and hydrogen for hydroformylation of 1-hexene. The catalyst was re-cycled up to five times without significant loss in the alkene conversion and selectivity of aldehydes.
- Sharma, Sumeet K.,Parikh, Parimal A.,Jasra, Raksh V.
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- Poly(ethylene glycol)-supported nitroxyls: Branched catalysts for the selective oxidation of alcohols
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Nitroxyl radicals such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) are highly selective oxidation catalysts for the conversion of primary alcohols into the corresponding aldehydes. In this study, direct tethering of TEMPO units onto linear poly(ethylene glycol) (PEG) has afforded macromolecular catalysts that exhibit solubility in both aqueous and organic solvents. Recovery of the dissolved polymer-supported catalyst has been carried out by precipitation with a suitable solvent such as diethyl ether. The high catalyst activities and selectivities associated traditionally with nitroxyl-mediated oxidations of alcohols are retained by the series of "linker-less" linear PEG-TEMPO catalysts in which the TEMPO moiety is coupled directly to the PEG support. Although the selectivity remains unaltered, upon recycling of the linker-less polymer-supported catalysts, extended reaction times are required to maintain high yields of the desired carbonyl compounds. Alternatively, attachment of two nitroxyl radicals onto each functionalized PEG chain terminus via a 5-hydroxyisophthalic acid linker affords branched polymer-supported catalysts. In stark contrast to the linker-less catalysts, these branched nitroxyls exhibit catalytic activities up to five times greater than 4-methoxy-TEMPO alone under similar conditions. In addition, minimal decrease in catalytic activity is observed upon recycling of these branched macromolecular catalysts via solvent-induced precipitation. The high catalytic activities and preservation of activity upon recycling of these branched systems is attributed to enhanced regeneration of the nitroxyl species as a result of intramolecular syn-proportionation.
- Ferreira, Pedro,Phillips, Emyr,Rippon, David,Shik, Chi Tsang,Hayes, Wayne
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- SiO2-TBD as new heterogeneous catalyst for the nef conversion of secondary nitroalkanes under neat conditions
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Treatment of secondary nitroalkanes with neat silica-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), at room temperature, allows the direct conversion of the secondary nitro groups to the corresponding keto carbonyls. Georg Thieme Verlag Stuttgart.
- Ballini, Roberto,Fiorini, Dennis,Maggi, Raimondo,Oro, Chiara,Palmieri, Alessandro,Sartori, Giovanni
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- Copper(I)- and Mesoionic-Hydroxyamide-Catalyzed Chemoselective Aerobic Oxidation of Primary Benzylic Alcohols
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A new aerobic oxidation system consisting of Cu(I)I, 2,2'-bipyridine, N -methyl imidazole, and a mesoionic hydroxyamide was developed, with which selective oxidation of a broad range of benzylic alcohols was achieved.
- Matsukawa, Yuta,Hirashita, Tsunehisa
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- Ionic TEMPO in Ionic Liquids: Specific Promotion of the Aerobic Oxidation of Alcohols
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The main objective of this study was to design a recyclable TEMPO (2,2,6,6-tetramethylpiperidinyl-N-oxyl) derivative that could be used as a catalyst in an ionic liquid solvent for the aerobic oxidation of alcohols by using NaNO2 and HCl as co-catalysts. To this end, a TEMPO derivative bearing a quaternary ammonium group, [4-Bu2MeN-TEMPO][PF6] (1), was prepared. It was subsequently shown that this ionic TEMPO derivative is an efficient catalyst for the aerobic oxidation of a variety of primary and secondary alcohols. It exhibits a synergistic effect with ionic liquid solvents and readily outperforms analogous oxidations in methylene chloride. Moreover, the ionic TEMPO could be recycled five times with no loss of activity.
- Hirashita, Tsunehisa,Nakanishi, Makoto,Uchida, Tomoya,Yamamoto, Masakazu,Araki, Shuki,Arends, Isabel W. C. E.,Sheldon, Roger A.
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- Electrochemical generation of cationic Pd catalysts and application to Pd/TEMPO double-mediatory electrooxidative Wacker-type reactions
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We have developed an electrooxidative method for generating cationic palladium complexes [Pd(CH3CN)4][X]2 (X = BF4, PF6, and ClO4) from Pd(OAc)2 and several electrolytes bearing X groups in CH3CN. The system could be integrated into an electrochemical Wacker-type reaction. In the presence of a catalytic amount of TEMPO, the reaction proceeded smoothly to give the corresponding methyl ketones. Copyright
- Mitsudo, Koichi,Kaide, Takashi,Nakamoto, Eriko,Yoshida, Kenta,Tanaka, Hideo
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- Indirect Electrooxidation of Alcohols by a Double Mediatory System with Two Redox Couples of +=O>/R2NO. and . or Br+>/Br- in an Organic-Aqueous Two-Phase Solution
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An indirect electrooxidation method for alcohol to aldehyde or ketone conversion has been developed.This method, applicable to chemoselective oxidation, employs two redox couples, consisting of 2,2,6,6-tetramethylpiperidine-1-oxyl derivatives 6 and active bromine species.The former is required for the chemical process and recycled, whereas the latter is to be involved in the electrochemical process.Three chemical events play an important role in this system: (1) the formation of . or Br+> from bromide ion by discharge on the anode in an aqueous solution, (2) the reaction of N-oxyl compounds 6 with active bromine species to generate N-oxoammonium ion 7, and (3) the oxidation of alcohols with 7 in an organic phase.Optimum conditions were established as follows: an aqueous 25percent NaBr solution buffered at pH 8.6 in a binary system, the use of 1-10 mol percent of 4-(benzoyloxy)piperidine derivatives 6, and adjustment of an electric current at 10-100 mA/cm2.The successful applications of the present method to the oxidation of a variety of primary and secondary alcohols including 1,n-diols, giving the corresponding carbonyl compounds, have delineated its synthetic utility.The chemoselective oxidation of a primary hydroxy group in the presence of secondary one has been achieved with a high selectivity by the present procedure.
- Inokuchi, Tsutomu,Matsumoto, Sigeaki,Torii, Sigeru
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- Efficient One-Pot Multifunctionalization of Alkynes en Route to α-Alkoxyketones, α-Thioketones, and α-Thio Thioketals by using an Umpolung Strategy
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The use of polarized synthons is a highly desirable strategy, as it generally enables unprecedented retrosynthetic disconnections for the synthesis of unique substances. Herein, a new approach for α-oxygenated ketones, α-thioketones and α-thio thioketals via an intermolecular umpolung reaction between nucleophiles (alcohols/thioalcohols) and N-alkenoxypyridinium salts, which were generated from the corresponding alkynes, has been developed for the first time. The reactions proceed with good substrate scope and excellent functional group tolerance in one-pot manner. Applications of the products, α-oxygenated ketones, to the synthesis of other valuable synthetic moieties has also been successfully achieved.
- Xu, Zhou,Zhai, Rongliang,Liang, Ting,Zhang, Liming
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- Electrochemical Wacker Type Reaction with a Double Mediatory System Consisting of Palladium Complex and Tri(4-bromophenyl)amine
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The electrochemical Wacker type oxidation of terminal olefins by using palladium chloride or palladium acetate and tri(4-bromophenyl)amine as a recyclable mediator in either a divided cell or an undivided cell afforded the corresponding methyl ketones in good yields.
- Inokuchi, Tsutomu,Ping, Liu,Hamaue, Fumihiro,Izawa, Miyoko,Torii, Sigeru
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- Aerobic oxidation of alcohols to carbonyl compounds mediated by poly(ethylene glycol)-supported TEMPO radicals
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Two poly(ethylene glycol)-supported TEMPO (PEG-TEMPO) has been successfully applied as soluble, recyclable catalysts in the chemoselective oxidation of primary and benzylic alcohols with molecular oxygen in the presence of Co(NO3)2 and Mn(NO3)2 as co-catalysts (Minisci's conditions). Under those conditions, secondary alcohols are also oxidized to ketones, although usually in lower yields. The insertion of a spacer between the PEG moiety and TEMPO has beneficial effects on both the activity and ease of recovery of the supported catalyst.
- Benaglia, Maurizio,Puglisi, Alessandra,Holczknecht, Orsolya,Quici, Silvio,Pozzi, Gianluca
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- A BIOMIMETIC SYNTHESIS OF (+/-)-NANAOMYCIN A
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A biosynthetic intermediate of isochromanequinone antibiotics was synthesized, and biomimetically converted to (+/-)-nanaomycin A.A novel synthetic method of methyl ketones from esters was also developed.
- Yamaguchi, Masahiko,Nakamura, Shigeo,Okuma, Tadashi,Minami, Toru
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- Unexpected Reactions of α,β-Unsaturated Fatty Acids Provide Insight into the Mechanisms of CYP152 Peroxygenases
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CYP152 peroxygenases catalyze decarboxylation and hydroxylation of fatty acids using H2O2 as cofactor. To understand the molecular basis for the chemo- and regioselectivity of these unique P450 enzymes, we analyze the activities of three CYP152 peroxygenases (OleTJE, P450SPα, P450BSβ) towards cis- and trans-dodecenoic acids as substrate probes. The unexpected 6S-hydroxylation of the trans-isomer and 4R-hydroxylation of the cis-isomer by OleTJE, and molecular docking results suggest that the unprecedented selectivity is due to OleTJE’s preference of C2?C3 cis-configuration. In addition to the common epoxide products, undecanal is the unexpected major product of P450SPα and P450BSβ regardless of the cis/trans-configuration of substrates. The combined H218O2 tracing experiments, MD simulations, and QM/MM calculations unravel an unusual mechanism for Compound I-mediated aldehyde formation in which the active site water derived from H2O2 activation is involved in the generation of a four-membered ring lactone intermediate. These findings provide new insights into the unusual mechanisms of CYP152 peroxygenases.
- Jiang, Yuanyuan,Li, Shengying,Li, Zhong,Peng, Wei,Tang, Dandan,Wang, Binju,You, Cai,Zhao, Yue
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supporting information
p. 24694 - 24701
(2021/10/14)
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- Preparation method of (cyclic)alkyl acetone
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A purpose of the invention is to provide a preparation method of (cyclic)alkyl acetone. The preparation method specifically comprises: sequentially adding acetic acid, potassium acetate, manganese acetate, acetic anhydride and acetone into a reaction flask, heating to a reaction temperature, adding olefin and an oxidant, and carrying out a free radical addition reaction represented by the following formula 2 at a reaction temperature of 30-100 DEG C to obtain (cyclic) alkyl acetone represented by a formula 2. According to the present invention, the preparation method is simple and safe to operate, and low in production cost.
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(2020/01/08)
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- Hydrofunctionalization of Olefins to Higher Aliphatic Alcohols via Visible-Light Photocatalytic Coupling
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Abstract: An atomically economical green protocol for the hydrofunctionalization of olefins to higher aliphatic alcohols with 100% anti-Markovnikov regioselectivity was developed via visible-light photocatalytic coupling. This method employs cheap, readily available and abundant methanol as both the C1 feedstock and the hydrogen source under visible light irradiation over CdS photocatalyst. A wide scope of olefin substrates could be hydrofunctionalized successfully to the corresponding higher alcohols with high selectivity. Besides alcohol, acetone and acetonitrile can also couple with olefins to generate the corresponding hydrofunctionalization products, suggesting promising potential industrial application. Graphical Abstract: [Figure not available: see fulltext.] Hydrofunctionalization of olefins to value-added chemicals with high selectivity was achieved via visible-light photocatalytic cross-coupling.
- Bao, Jingxian,Fan, Yonghui,Zhang, Shuyi,Zhong, Liangshu,Wu, Minghong,Sun, Yuhan
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- Nitrosotetrazolium-Catalyzed Aerobic Oxidation of Alcohols to the Corresponding Carbonyl Compounds
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A mesoionic-nitrosotetrazolium-catalyzed aerobic oxidation of alcohols is reported. In the presence of catalytic amounts of 5-nitroso-1,3-diphenyltetrazolium tetrafluoroborate (5 mol-%) and nitric acid (20 mol-%), a wide range of alcohols are oxidized to the corresponding aldehydes and ketones in yields of 53–100 % at room temperature under ambient air or oxygen conditions. This oxidation shows a strong preference for secondary alcohols over primary alcohols; sterically hindered alcohols are also smoothly oxidized. A mechanism involving a nitroso/NOx catalytic cycle is proposed.
- Matsukawa, Yuta,Hirashita, Tsunehisa,Araki, Shuki
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p. 1359 - 1363
(2018/04/02)
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- Highly practical and efficient preparation of aldehydes and ketones from aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst
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Herein, we divulge an efficient protocol for aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst, (NH4)5[IMo6O24]. The catalyst system is compatible with a wide range of groups and exhibits high selectivity, and shows excellent stability and reusability, thus serving as a potentially greener alternative to the classical transformations.
- Zhang, Mengqi,Zhai, Yongyan,Ru, Shi,Zang, Dejin,Han, Sheng,Yu, Han,Wei, Yongge
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supporting information
p. 10164 - 10167
(2018/09/13)
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- Oxidation of Secondary Methyl Ethers to Ketones
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We present a mild way of converting secondary methyl ethers into ketones using calcium hypochlorite in aqueous acetonitrile with acetic acid as activator. The reaction is compatible with various oxygen- and nitrogen-containing functional groups and afforded the corresponding ketones in up to 98% yield. The use of this methodology could expand the application of the methyl group as a useful protecting group.
- Gilissen, Pieter J.,Blanco-Ania, Daniel,Rutjes, Floris P. J. T.
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p. 6671 - 6679
(2017/07/15)
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- Method of manufacturing calbonyl compd.
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PROBLEM TO BE SOLVED: To provide a method of manufacturing a carbonyl compound by smoothly performing a dehydrogenation reaction while preventing side reactions.SOLUTION: A method of manufacturing a carbonyl compound includes a process of converting alcohol to aldehyde or ketone by irradiating visible light to a reaction system containing a primary alcohol or a secondary alcohol, SrTiOcarrying a Ru atom and doped with Rh atom, and water.
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Paragraph 0051; 0053
(2018/06/30)
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- Chemoselective Ketone Synthesis by the Addition of Organometallics to N-Acylazetidines
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A general and highly chemoselective method for the synthesis of ketones by the addition of organometallics to N-acylazetidines via stable tetrahedral intermediates is reported for the first time. The transformation is characterized by its wide substrate scope and exquisite selectivity for the ketone products even when a large excess of nucleophilic reagents is used. Even of broader interest is the use of N-acylazetidines as bench-stable, readily available amide acylating reagents, in which the reactivity is controlled by amide pyramidalization and strain of the four-membered ring to afford synthetically valuable building blocks.
- Liu, Chengwei,Achtenhagen, Marcel,Szostak, Michal
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p. 2375 - 2378
(2016/06/09)
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- Regioselective Cleavage of Electron-Rich Double Bonds in Dienes to Carbonyl Compounds with [Fe(OTf)2(mix-BPBP)] and a Combination of H2O2 and NaIO4
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A method for the regioselective transformation of dienes to carbonyl compounds has been developed. Electron-rich olefins react selectively to yield valuable aldehydes and ketones. The method is based on the catalyst [Fe(OTf)2(mix-BPBP)] with an oxidant combination of H2O2 (1.0 equiv.) and NaIO4 (1.5 equiv.); it uses mild conditions and short reaction times, and it outperforms other olefin cleavage methodologies. The combination of an Fe-based catalyst, [Fe(OTf)2(mix-BPBP)], and the oxidants H2O2 and NaIO4 can discriminate between electronically different double bonds and oxidatively cleave the electron-rich bond in dienes to yield aldehydes and ketones in a regioselective manner. The reaction requires mild conditions (0-50 C) and short reaction times (70 min).
- Spannring, Peter,Yazerski, Vital A.,Chen, Jianming,Otte, Matthias,Weckhuysen, Bert M.,Bruijnincx, Pieter C. A.,Klein Gebbink, Robertus J. M.
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p. 3462 - 3466
(2015/08/06)
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- Iron(II) α-aminopyridine complexes and their catalytic activity in oxidation reactions: A comparative study of activity and ligand decomposition
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New well-defined FeII complexes bearing bi- and tridentate α-aminopyridine ligands were synthesized, and their catalytic activity in the oxidation of hydrocarbons and alcohols utilizing peroxide oxidants was investigated. The tridendate bis-(picolyl)amine ligand 6 and its benzylated analogue 7 were converted into complexes [FeII(6)2] OTf2 (96 %, X-ray; OTf= CF3SO3 -) and [FeII(7)2]OTf2 (90 %). The bidentate aminopyridine ligand 8 was converted into [FeII(8) 2(OTf)2] (93 %, X-ray). The new complexes are catalytically active in the oxidation of secondary alcohols and benzylic methylene groups to the corresponding ketones, of toluene to benzaldehyde, and of cyclohexene to cyclohexene oxide (3 mol% catalyst, tBuOOH (4 equiv), RT, 2-6 h, 28 to 85% yield of isolated product). The catalytic oxidation of cyclohexane with ROOH (R=H, tBu) to an alcohol/ketone mixture with low ratio revealed that these oxidations follow largely a radical mechanism, except when [Fe II(6)2]OTf2 was employed and H 2O2 was added slowly. Together with known bi- and tetradendate iron complexes, a comparative study showed slight reactivity differences for the newly prepared complexes, with the highest observed for [FeII(6)2]OTf2 and [FeII(7) 2]OTf2. The reaction of the new complexes with peroxides was followed over time by UV/Visible spectroscopy; this revealed a fast reaction between the two reactants within minutes. Ligand-decomposition pathways were investigated, and revealed that the NCH2 units of the complexes are rapidly oxidized to the corresponding amides NC=O. The iron complex [Fe II(6)2]OTf2 showed no decrease in catalytic activity and a moderate decrease in selectivity when first subjected to oxidative conditions similar to those employed in catalysis. Thus, oxidative ligand deterioration had a marginal effect on the catalytic activity of the iron complex [FeII(6)2]OTf2.
- Lenze, Matthew,Martin, Erin T.,Rath, Nigam P.,Bauer, Eike B.
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p. 101 - 116
(2013/05/22)
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- Environmentally benign deprotection of dithioacetals using 30% hydrogen peroxide catalyzed by Fe(acac)3 and sodium iodide
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The reaction of dithioacetals with 30% hydrogen peroxide in the presence of catalytic amounts of iron(III) acetylacetonate and sodium iodide efficiently produced the corresponding carbonyl compounds in high yields.
- Kirihara, Masayuki,Suzuki, Satoshi,Ishizuka, Yuki,Yamazaki, Kento,Matsushima, Ryoji,Suzuki, Takaya,Iwai, Toshiaki
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p. 5477 - 5480
(2013/09/23)
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- Method for Synthesis of Ketones from Plant Oils
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Ketones may be produced in high yields from glycerides of short chain fatty acids by reaction with a carboxylic acid. The reaction is conducted in the presence of a catalyst and under conditions effective for ketonization of decanoate with the carboxylic acid to produce free ketones. Reaction of a glyceride comprising at least one ester of decanoic acid with a carboxylic acid selected from acetic acid and/or propionic acid produces 2-undecanone and/or 3-dodecanone, respectively. Catalysts of the formula FemCenAlpOx, wherein m is between about 0.2 to about 0.6, n is about 0.2, p is between about 0.6 to about 0.2, and x is greater than 0, produce significantly higher yields of the ketones than other known metal oxides.
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Paragraph 0035
(2013/07/31)
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- Deprotection of 1,3-oxathiolanes to ketones promoted by base
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A variety of 1,3-oxathiolanes can be easily converted to the corresponding ketones in good yields with LTMP in THF. This deprotection methodology shows satisfactory chemoselectivity when other protecting groups, such as dimethylketal, 1,3-dioxolane, 1,3-dithiane, and other acid-sensitive groups, are present within the same substrates.
- Du, Biao,Yuan, Changchun,Zhang, Langzhong,Yang, Li,Liu, Bo
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supporting information
p. 2217 - 2220
(2013/05/08)
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- Modified Marko's aerobic oxidation of alcohols under atmospheric pressure with air or molecular oxygen at room temperature
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A modified version of Marko's aerobic oxidation procedure, using highly pure (99.995+%) CuCl with 4,7-diphenyl-1,10-phenanthroline (dpPhen), DBAD, and Cs2CO3 (98% purity) successfully oxidized primary and secondary alcohols to the corresponding aldehydes and ketones in excellent yield at room temperature with either air or molecular oxygen under atmospheric pressure.
- Nishii, Takeshi,Ouchi, Tomomi,Matsuda, Aya,Matsubara, Yuka,Haraguchi, Yuuko,Kawano, Tomomi,Kaku, Hiroto,Horikawa, Mitsuyo,Tsunoda, Tetsuto
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p. 5880 - 5882,3
(2020/07/31)
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- Deprotection of dithioacetals with 30% hydrogen peroxide catalyzed by tantalum(V) chloride-sodium iodide or niobium(V) chloride-sodium iodide
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The reaction of dithioacetals with 30% hydrogen peroxide in the presence of catalytic amounts of tantalum(V) and iodide ion effectively produced carbonyl compounds in high yields. Dithioacetals also can be deprotected using the niobium(V) catalyzed oxidation of iodide ion by hydrogen peroxide under mild conditions.
- Kirihara, Masayuki,Noguchi, Takuya,Okajima, Nobuhiro,Naito, Sayuri,Ishizuka, Yuki,Harano, Aiko,Tsukiji, Hiroyuki,Takizawa, Ryu
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experimental part
p. 1515 - 1520
(2012/03/07)
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- Oxidation with a photolabile carbonyl protecting group
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A novel oxidation approach utilizing a robust photolabile carbonyl protecting group reagent (1) as the oxidizing reagent has been developed. Different from existing methods, this approach oxidizes primary alcohols to the photosensitive acetals (e.g., 3), providing another unique approach to the protected aldehydes. Thus, for the first time, oxidation and protection are achieved in one reaction. Secondary alcohols are oxidized to the corresponding ketones. Moreover, the photolabile protecting group (PPG) also oxidizes ethers and esters. The oxidation is presumably via hydride abstraction by the tritylium ion generated from 1 under acidic conditions. However, the mechanisms for primary alcohols and secondary alcohols are slightly different.
- Yang, Haishen,Mu, Feng,Wang, Pengfei
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experimental part
p. 8955 - 8961
(2011/12/15)
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- New iron(ii) α-iminopyridine complexes and their catalytic activity in the oxidation of activated methylene groups and secondary alcohols to ketones
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A set of iron(ii) complexes of the general formula [Fe(OTf) 2L2] was synthesized in 32 to 78% isolated yields, where L represents a bidentate α-iminopyridine ligand. Four of the iron complexes were characterized structurally, revealing a rich coordination chemistry, because the coordination geometry of the iron complexes strongly depends on the substitution pattern exhibited by the ligands L. The catalytic activity of the new complexes was demonstrated in the oxidation of cyclohexane, activated methylene groups and secondary alcohols to the corresponding ketones utilizing H2O2 and t-BuOOH as the oxidants. The oxidation of activated methylene groups and secondary alcohols to the corresponding ketones with t-BuOOH gave isolated yields between 22 and 91% (4 h, room temperature, 3% catalyst load). The influence of the structure of the ligand on the activity of the corresponding metal complex is also reported. Furthermore, UV-vis experiments were performed which provided evidence for the formation of an [Fe-O-O-t-Bu] intermediate. The Royal Society of Chemistry 2011.
- Shejwalkar, Pushkar,Rath, Nigam P.,Bauer, Eike B.
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supporting information; experimental part
p. 7617 - 7631
(2011/10/19)
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- Highly regio- and enantioselective organocatalytic conjugate addition of alkyl methyl ketones TO A β-silylmethylene malonate
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(S)-N-(2-Pyrrolidinylmethyl)pyrrolidine/trifluoroacetic acid (3:1) combination catalyzed the direct addition of alkyl methyl ketones to β-dimethyl(phenyl)silylmethylene malonate at the methyl terminal with high yield and excellent regio- and enantioselectivity. The silyl group played crucial roles in regioselection and substrate reactivity.
- Chowdhury, Raghunath,Ghosh, Sunil K.
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supporting information; experimental part
p. 3270 - 3273
(2009/12/01)
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- Oxidation of organic substrates using two triethylammonium halochromates(VI), (C2H5)3NH[CrO3X], (X=F, Cl) supported on silica gel
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Triethylammonium fluorochromate(VI), (C2H5) 3NHCrO3F, TriEAFC and triethylammonium chlorochromate(VI), (C2H5)3NHCrO3Cl, TriEACC were prepared, supported on silica gel and used to quantitatively oxidize a number of organic substrates. These supported triethylammonium halochromates are versatile reagents ensuring effective oxidation of organic compounds, in particular of alcohols, under mild conditions. The durability, ease of work up and efficiency of TriEAFC and TriEACC are considerably increased upon their absorption on silica gel.
- Ghammamy, Shahriare,Dastpeyman, Samaneh
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scheme or table
p. 229 - 232
(2009/04/06)
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- A high performance oxidation method for secondary alcohols by inductive activation of TEMPO in combination with pyridine-bromine complexes
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A new TEMPO-mediated catalytic oxidation method in combination with Py·HBr3 (stoichiometric) is developed for oxidation of secondary alcohols to the corresponding ketones. The performance of this oxidizing system is better compared with that of TEMPO method combined with R4NBr3. Poly(4-vinylpyridine)·HBr3 can be used in place of Py·HBr3. The electron-withdrawing substituent at the C-4 position of TEMPO increases the reactivity of TEMPO significantly in the oxidation of electron-deficient alcohols such as polyhaloalkylmethanols. Inductive effect of the substituent of TEMPO is discussed through the characterization of the redox potential of N-O radical by cyclic voltammetry.
- Mei, Zhen-Wu,Omote, Takumi,Mansour, Mounir,Kawafuchi, Hiroyuki,Takaguchi, Yutaka,Jutand, Anny,Tsuboi, Sadao,Inokuchi, Tsutomu
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experimental part
p. 10761 - 10766
(2009/04/11)
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- Highly efficient methyl ketone synthesis by water-assisted C-C coupling between olefins and photoactivated acetone
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(Chemical Equation Presented) Photoirradiation of an acetone/water mixture containing olefins affords the corresponding methyl ketones highly efficiently via a water-assisted CsC coupling between acetonyl radical and olefins.
- Shiraishi, Yasuhiro,Tsukamoto, Daijiro,Hirai, Takayuki
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scheme or table
p. 3117 - 3120
(2009/05/07)
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- Direct addition of supercritical alcohols, acetone or acetonitrile to the alkenes without catalysts
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The reactions of the alkenes with supercritical organic compounds under non-catalytic conditions were investigated. The H and CR2OH, CH2C{double bond, long}OCH3 or CH2C{triple bond, long}N of supercritical alcohols (CHR2OH), acetone (CH3C{double bond, long}OCH3) or acetonitrile (CH3C{triple bond, long}N) added to the C{double bond, long}C bonds of alkenes form C-C bonds between the α-carbons of the supercritical organic compounds and the sp2 carbons of the alkenes.
- Kamitanaka, Takashi,Hikida, Tatsuyoshi,Hayashi, Satoshi,Kishida, Nobuhiro,Matsuda, Tomoko,Harada, Tadao
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p. 8460 - 8463
(2008/03/13)
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- Extensive isomerization of alkenes using a bifunctional catalyst: An alkene zipper
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Catalyzed movement of alkene double bonds up to 30 positions has been accomplished using a catalyst featuring a cationic CpRu fragment and bifunctional imidazolylphosphine. The basic nitrogen of the latter is thought to deprotonate coordinated alkene intermediates reversibly, facilitating isomerization between terminal and (E)-alkenes and accelerating conversions by factors of up to 1 × 104. Copyright
- Grotjahn, Douglas B.,Larsen, Casey R.,Gustafson, Jeffery L.,Nair, Reji,Sharma, Abhinandini
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p. 9592 - 9593
(2008/03/11)
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- A new synthetic method for methyl ketones from carboxylic acids using metallic strontium and methyl iodide
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Carboxylic acids reacted with metallic strontium and methyl iodide to give methyl ketones preferentially in moderate to good yields. Copyright
- Miyoshi, Norikazu,Matsuo, Tsuyoshi,Asaoka, Masashi,Matsui, Aki,Wada, Makoto
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- Catalytic deprotection of acetals in basic solution with a self-assembled supramolecular "nanozyme"
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(Formula Presented) Changing on the inside: Acetals are a commonly used protecting groups for aldehydes and ketones in organic synthesis because of their ease of installation and resistance to cleavage in neutral or basic solution. A self-assembled supramolecular assembly has been shown to catalyze the hydrolysis of acetals and ketals in basic solution (see scheme).
- Pluth, Michael D.,Bergman, Robert G.,Raymond, Kenneth N.
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p. 8587 - 8589
(2008/09/18)
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- Trimethylammonium fluorochromate (TriMAFC): A convenient new and mild reagent for oxidation of organic substrates
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Trimethylammonium fluorochromate (TriMAFC) is easily synthesized by addition of a trimethylamine to an aqueous solution of CrO3 and HF and used for quantitative oxidation of several organic substrates. This reagent is a versatile reagent for the effective and selective oxidation of organic substrates, in particular for alcohols, under mild conditions.
- Sadjadi, S. A. Seyed,Ghammamy
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p. 564 - 567
(2007/10/03)
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- 'Reductive ozonolysis' via a new fragmentation of carbonyl oxides
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This account describes the development of methodologies for 'reductive' ozonolysis, the direct ozonolytic conversion of alkenes into carbonyl groups without the intermediacy of 1,2,4-trioxolanes (ozonides). Ozonolysis of alkenes in the presence of DMSO produces a mixture of aldehyde and ozonide. The combination of DMSO and Et3N results in improved yields of carbonyls but still leaves unacceptable levels of residual ozonides; similar results are obtained using secondary or tertiary amines in the absence of DMSO. The influence of amines is believed to result from conversion to the corresponding N-oxides; ozonolysis in the presence of amine N-oxides efficiently suppresses ozonide formation, generating high yields of aldehydes. The reactions with amine oxides are hypothesized to involve an unprecedented trapping of carbonyl oxides to generate a zwitterionic adduct, which fragments to produce the desired carbonyl group, an amine, and 1O2.
- Schwartz, Chris,Raible, Joseph,Mott, Kyle,Dussault, Patrick H.
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p. 10747 - 10752
(2007/10/03)
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- Wacker oxidation of terminal olefins in a mixture of [bmim][BF4] and water
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A simple and efficient PdCl2/CuCl catalyzed oxidation of alkenes has been successfully developed using a mixture of water and the ionic liquid [bmim][BF4] as solvent. Starting from various types of terminal olefins, the corresponding ketones have been prepared under mild reaction conditions and obtained in good to excellent yields after a simple extraction with diethyl ether. Furthermore, it was possible to recycle and reuse the ionic liquid and the catalytic system.
- Ansari,Joyasawal, Sipak,Gupta, Manoj K.,Yadav,Gree
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p. 7507 - 7510
(2007/10/03)
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- Ruthenium-catalyzed hydrative dimerization of allenes
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Hydrative dimerization and hydration of allenes proceeded in the presence of a ruthenium catalyst and a strong acid such as trifluoroacetic acid. γ,δ-Unsaturated ketones and methyl ketones were isolated in moderate combined yields. No isomeric compound (isomeric enone) was isolated. Copyright
- Saito, Shinichi,Dobashi, Naotomo,Wakatsuki, Yasuo
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p. 504 - 505
(2007/10/03)
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- Nitrous oxide oxidation catalyzed by ruthenium porphyrin complex
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Dinitrogen oxide was employed as a clean oxidant for various oxidations in the presence of a catalytic amount of dioxoruthenium tetramesitylporphyrin complex (Ru(tmp)(O)2). A variety of olefins, secondary alcohols, and benzyl alcohols were smoothly oxidized to the corresponding epoxides, ketones, and aldehydes in high yields. In the oxidation of 9,10-dihydroanthracene derivatives, the competitive reactions affording anthraquinones and anthracenes could be regulated by the reaction conditions. At a high temperature (200°C), anthraquinones were selectively produced, while the anthracenes were selectively produced by the addition of sulfuric acid.
- Tanaka, Hirotaka,Hashimoto, Kentaro,Suzuki, Kyosuke,Kitaichi, Yasunori,Sato, Mitsuo,Ikeno, Taketo,Yamada, Tohru
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p. 1905 - 1914
(2007/10/03)
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- Poly(ethylene glycol)-Supported TEMPO: An Efficient, Recoverable Metal-Free Catalyst for the Selective Oxidation of Alcohols
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(Matrix presented) Poly(ethylene glycol)-supported TEMPO (PEG-TEMPO) has been prepared, and its catalytic activity in the chemoselective oxidation of alcohols with stoichiometric amounts of organic or inorganic oxidants has been investigated. The new metal-free catalyst exhibits high activity and is easily removed from the reaction mixture by filtration. Recycling experiments showed that PEG-TEMPO can be reused up to six times with no loss of catalytic activity.
- Pozzi, Gianluca,Cavazzini, Marco,Quici, Silvio,Benaglia, Maurizio,Dell'Anna, Gianmaria
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p. 441 - 443
(2007/10/03)
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- Catalytic ketonisation over oxide catalysts. Part IX. Single step synthesis of aliphatic saturated and unsaturated C11 - C 13 ketones from carboxylic acids
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Metameric undecan-x-ones (x = 2-6), dodecan-y-ones (y = 2-5), tridecan-z-ones (z = 4-7) and two unsaturated aliphatic ketones were prepared by vapor phase ketonisation of the appropriate monocarboxylic acids in the presence of 20 wt% MnO2/Al2O3 catalyst under flow conditions. The ketones were obtained in yields between 48 and 89% in a multigram scale (80-250 g). Their physical and spectral data have been determined.
- Glinski,Gibka
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p. 299 - 302
(2007/10/03)
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- Transformation of β-chalcogeno alkenylboranes into tetrasubstituted olefins
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In view of generating trisubstituted vinylic chalcogen derivatives, β-chalcogeno alkenylboranes generated through the chalcogen electrophile induced rearrangements of 1-alkynyltrialkyl borates have been subjected to Suzuki-Miyaura coupling and to boron to copper transmetalation followed by alkylation. Some of the trisubstituted vinyl sulfides obtained by this latter strategy have been converted efficiently into the title olefins through the NiCl2(dmpe) catalyzed coupling with various Grignard reagents.
- Gerard, Julien,Hevesi, László
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p. 367 - 381
(2007/10/03)
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- Serine carbonates
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Serine carbonates of formula I are precursors for organoleptic compounds, masking agents and antimicrobial agents. Further they are alternative substrates for malodor producing enzymes. The symbols in formula I are defined in claim 1.
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