- REGIOSELECTIVE OXIDATION OF INTERNAL OLEFINS BEARING NEIGHBORING OXYGEN FUNCTIONS BY MEANS OF PALLADIUM CATALYSTS. A DIRECT PREPARATION OF γ-KETO ESTERS AND 1,4-DIKETONES FROM β,γ-UNSATURATED ESTERS AND KETONES
-
γ-Keto esters and 1,4-diketones were prepared by the palladium-catalyzed regioselective oxidation of β,γ-unsaturated esters and ketones.The best yields were obtained when the reaction was carried out using PdCl2/CuCl/O2 catalyst system in aqueous dioxane.
- Nagashima, Hideo,Sakai, Kiyomi,Tsuji, Jiro
-
-
Read Online
- Synthesis of Diketones, Ketoesters, and Tetraketones by Electrochemical Oxidative Decarboxylation of Malonic Acid Derivatives: Application to the Synthesis of cis-Jasmone
-
Disubstituted malonic acid derivatives are smoothly converted into diketones and ketoesters in good to excellent yield (68% to 91%) under electrochemical conditions. The scope can be extended to transform trisubstituted bis-malonic acids into tetraketones in 77% to 86% yield. The new method was applied to the total synthesis of cis-jasmone.
- Ma, Xiaofeng,Du, Le,Luo, Xiya,Markó, István E.,Dewez, Damien F.,Lam, Kevin
-
p. 12044 - 12055
(2019/03/01)
-
- Synthesis of Diketones, Ketoesters, and Tetraketones by Electrochemical Oxidative Decarboxylation of Malonic Acid Derivatives: Application to the Synthesis of cis-Jasmone
-
Disubstituted malonic acid derivatives are smoothly converted into diketones and ketoesters in good to excellent yield (68% to 91%) under electrochemical conditions. The scope can be extended to transform trisubstituted bis-malonic acids into tetraketones in 77% to 86% yield. The new method was applied to the total synthesis of cis-jasmone.
- Ma, Xiaofeng,Dewez, Damien F.,Du, Le,Luo, Xiya,Markó, István E.,Lam, Kevin
-
-
- Pheromone synthesis. Part 262: Determination of the absolute configuration of the female sex pheromone [(1S,2S)-(?)-(1,2-dimethyl-3-methylenecyclopentyl) acetaldehyde] of the pineapple mealybug (Dysmicoccus brevipes) by synthesis coupled with X-ray analysis
-
The enantiomers of (anti-1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde, one of which is the female sex pheromone of the pineapple mealybug (Dysmicoccus brevipes), were synthesized. Chirality was introduced by means of lipase-catalyzed asymmetric acetylation of (±)-2,3-dimethyl-2-cyclopenten-l-ol. X-ray analysis of (?)-camphanate ester of (1S,2S)-(?)-2-(1,2-dimethyl-3-methylenecyclopentyl)ethanol confirmed its (1S,2S)-absolute configuration. The natural pheromone was identified with the (1S,2S)-aldehyde by comparing the specific rotation, enantioselective GC retention time and pheromone activity.
- Mori, Kenji,Tabata, Jun
-
p. 6530 - 6541
(2017/10/17)
-
- Cp* iridium precatalysts for selective C-h oxidation with sodium periodate as the terminal oxidant
-
Sodium periodate (NaIO4) is shown to be a milder and more efficient terminal oxidant for C-H oxidation with CpIr (Cp* = C 5Me5) precatalysts than ceric(IV) ammonium nitrate. Synthetically useful yields, regioselectivities, and functional group tolerance were found for methylene oxidation of substrates bearing a phenyl, ketone, ester, or sulfonate group. Oxidation of the natural products (-)-ambroxide and sclareolide proceeded selectively, and retention of configuration was seen in cis-decalin hydroxylation. At 60 C, even primary C-H bonds can be activated: whereas methane was overoxidized to CO2 in 39% yield without giving partially oxidized products, ethane was transformed into acetic acid in 25% yield based on total NaIO4. 18O labeling was demonstrated in cis-decalin hydroxylation with 18OH2 and NaIO 4. A kinetic isotope effect of 3.0 ± 0.1 was found in cyclohexane oxidation at 23 C, suggesting C-H bond cleavage as the rate-limiting step. Competition experiments between C-H and water oxidation show that C-H oxidation of sodium 4-ethylbenzene sulfonate is favored by 4 orders of magnitude. In operando time-resolved dynamic light scattering and kinetic analysis exclude the involvement of metal oxide nanoparticles and support our previously suggested homogeneous pathway.
- Zhou, Meng,Hintermair, Ulrich,Hashiguchi, Brian G.,Parent, Alexander R.,Hashmi, Sara M.,Elimelech, Menachem,Periana, Roy A.,Brudvig, Gary W.,Crabtree, Robert H.
-
supporting information
p. 957 - 965
(2013/04/23)
-
- Mild oxidative conversion of nitroalkanes into carbonyl compounds in ionic liquids
-
Basic hydrogen peroxide and sodium perborate were found to be cheap and efficient alternatives for the conversion of primary and secondary nitro to carbonyl compounds (Nef reaction) in ionic liquids. Copyright Taylor & Francis Group, LLC.
- Bortolini, Olga,Nino, Antonio De,Garofalo, Angelo,Maiuolo, Loredana,Russo, Beatrice
-
scheme or table
p. 2483 - 2487
(2010/09/07)
-
- Nitroalkanes in Aqueous Medium as an Efficient and Eco-Friendly Source for the One-Pot Synthesis of 1,4-Diketones, 1,4-Diols, δ-Nitroalkanols, and Hydroxytetrahydrofurans
-
The Michael addition of primary aliphatic nitro compounds to α,β-unsaturated enones, performed in aqueous media, provides the one-pot synthesis of 1,4-diketones, 1,4-diols, δ-nitroalkanols, and hydroxytetrahydrofurans, respectively, by the appropriate cho
- Ballini, Roberto,Barboni, Luciano,Giarlo, Guido
-
p. 9173 - 9176
(2007/10/03)
-
- Unprecedented, selective Nef reaction of secondary nitroalkanes promoted by DBU under basic homogeneous conditions
-
Secondary nitrocompounds can be converted into the corresponding ketones under basic conditions using DBU in acetonitrile. Primary nitroalkanes are unaffected by these conditions. Elsevier Science Ltd. All rights reserved.
- Ballini, Roberto,Bosica, Giovanna,Fiorini, Dennis,Petrini, Marino
-
p. 5233 - 5235
(2007/10/03)
-
- Electrooxidative transformation of unsubstituted and substituted nitro hydrocarbons into carbonyl compounds
-
Alkaline salts of aci-forms of secondary nitro compounds, viz., β-nitropropylbenzene, nitrocyclohexane, 5-nitroheptan-2-one, and methyl-4-nitrohexanoate, were selectively or predominately oxidized into the corresponding ketones and their ketals under conditions of undivided amperostatic electrolysis in methanol. Mixtures of the corresponding aldehydes, their acetals, and methyl carboxylates were formed under similar conditions from the salts of primary nitro compounds, viz., 1-nitrohexane, nitromethylbenzene, and β-nitroethylbenzene.
- Ogibin,Ilovaiskii,Merkulova,Terent'ev,Nikishin
-
p. 1460 - 1465
(2007/10/03)
-
- Transition metal-catalysed acylation of α,β-unsaturated carbonyl compounds with acylstannanes
-
Acylstannanes were found to add to such α,β-unsaturated carbonyl compounds as enones or ynoates in the presence of a nickel or palladium catalyst to give 2-stannyl-4-oxoalk-2-enoates or 1,4-diketones, whereas the three component coupling between acylstannanes, enones and aldehydes provided 2-hydroxymethyl 1,4-diketones.
- Shirakawa,Yamamoto,Nakao,Tsuchimoto,Hiyama
-
p. 1926 - 1927
(2007/10/03)
-
- A mild and efficient Nef reaction for the conversion of nitro to carbonyl group by dimethyldioxirane (DMD) oxidation of nitronate anions
-
DMD oxidation of nitronate onions, generated in situ from the corresponding nitroalkanes, affords the corresponding carbonyl products. Highest yields were obtained when one equivalent of water was added before the oxidation with DMD.
- Adam, Waldemar,Makosza, Mieczyslaw,Saha-M?ller, Chantu R.,Zhao, Cong-Gui
-
p. 1335 - 1336
(2007/10/03)
-
- Facile Control of Regioselectivity in the Reaction of Tin Enolates with α-Halogeno Carbonyls by Additives
-
Tin enolates 1 reacted with α-halogeno ketones 2 and esters 10 to give a variety of 1,4-diketones 3 and γ-keto esters 11, respectively, in the presence of appropriate additives such as hexamethylphosphoric triamide (HMPT), tributylphosphine oxide and tetrabutylammonium bromide, while complexation of these additives with tributyltin bromide allowed catalytic production of β-keto oxiranes 4 instead of 3.The reaction mechanism for the preparation of 1,4-diketone 3 is discussed.
- Yasuda, Makoto,Oh-hata, Tatsuhiro,Shibata, Ikuya,Baba, Akio,Matsuda, Haruo
-
p. 859 - 866
(2007/10/02)
-
- Study of photochemical addition of acyl radical to electron-deficient olefins
-
The photochemical addition of acyl radical to electron-deficient olefins is studied. The scope of the reaction, the mechanism, the role that molecular oxygen plays, the influence of steric effects, and the side reaction that take place are discussed. The reaction was carried out using a range of electron-withdrawing substituents (ketones, amides, lactones, nitrile and esters) with good yields of the corresponding photoadduct in all cases.
- Macias,Molinillo,Massanet,Rodriguez-Luis
-
p. 3345 - 3352
(2007/10/02)
-
- A convenient synthesis of 1,4-diketones
-
A simple and short synthesis of 1,4-diketones was achieved via 2-chloro-5-methylthio-2,5-hexadienes and their hydrolysis with titanium tetrachloride.
- Motoyoshiya,Hongo,Tanaka,Hayashi
-
p. 997 - 1000
(2007/10/02)
-
- An efficient and mild entry to 1,4-dicarbonyl compounds via photochemical addition of acyl radical to electron-deficient olefins
-
Photoehcmical addition of acetaldehyde to electron-deficient olefins in the presence of molecular oxygen provides an efficient and mild method for the synthesis of 1,4-functionallzed compounds. Some considerations about the mechanism and the substituent effects are outlined.
- Macias, Francisco A.,Molinillo, Jose Maria G.,Collado, Isidro G.,Massanet, Guillermo M.,Rodriguez-Luis, Francisco
-
p. 3063 - 3066
(2007/10/02)
-
- REMOTE OXIDATION OF KETONES TO γ- AND δ-DIKETONES
-
A single stage remote oxidation of ketones to γ- and δ-diketones has been carried out in a sodium peroxysulfate-iron(II) sulfate system.
- Troyanskii, E.I.,Mizintsev, V. V.,Lazareva, M. I.,Demchuk, D. V.,Nikishin, G. I.
-
p. 1879 - 1884
(2007/10/02)
-
- MECHANISM OF RECYCLIZATION OF FURANS TO THIOPHENES AND SELENOPHENES UNDER ACID CATALYSIS. 1. KINETIC STUDIES OF THE REACTION OF 2,5-DIALKYLFURANS WITH HYDROGEN SULFIDE IN THE PRESENCE OF HYDROCHLORID ACID
-
The transformation of 2,5-dialkylfurans to thiophene by reaction with hydrogen sulfide in the presence of hydrochloric acid was studied.The reaction was found to be first order with respect to the furan; the rate of consumption of the furan did not change with the increasing length of one of the alkyl substituents.Recrystalization in the presence of acid proceeds in two independent directions: through the formation of an intermediate dicarbonyl compound, and by direct conversion of the furan to a thiophene.Kinetic data showed that the reaction occurs mainly by the second route.
- Voronin, S. P.,Gubina, T. I.,Markushina, I. A.,Kharchenko, V. G.
-
p. 1113 - 1117
(2007/10/02)
-
- Reactions of Some Cyclic Ethers in Superacids
-
The reactions of some epoxides and tetrahydrofuran derivatives in superacidic media have been studied.The tetrahydrofurans decompose only at 0 deg C or above, yielding, in some cases, unsaturated carbocations which react to give carbocyclic products, though many yield only tar.Cyclohexene oxides decompose more readily; unsubstituted, they slowly form an allylic ion; with one carbon at the epoxide link substituted they yield the ketone, and with both carbons substituted they give the ring-contracted aldehyde.Limonene 1,2-oxide behaves in a similar manner, though yielding small amounts of the ring-contracted protonated aldehyde (10).Reaction of geraniol 2,3-oxide is initially similar but the intermediate is intercepted intramolecularly to yield the hydroxy-iridoid ethers, 3,3,6β-trimethyl-cis-perhydrocyclopentafuran and 3,3,6α-trimethyl-cis-perhydrocyclopentafuran.Protonation of cyclohexene oxide or norbornene oxide yields onium salts, stable at -70 deg C, which show the addition to be either unsymmetrical (i.e. edge protonation) or to take place in two different positions.
- Baig, Mirza Azam,Banthorpe, Derek V.,Carr, Graham,Whittaker, David
-
p. 1981 - 1986
(2007/10/02)
-
- Utilization of Basic Alumina in a One-Pot Synthesis of 1,4-Diketones, 1,4,7-Triketones, and Dihydrojasmone by Conjugate Addition of Nitroalkanes to Enones
-
The one-pot synthesis of functionalized 1,4-diketones was achieved in good yields by conjugate addition of primary nitroalkanes to α,β-unsaturated carbonyl compounds on basic alumina without solvent, followed by in situ oxidation with 30percent aqueous hydrogen peroxide in methanol.The one-pot syntheses of 1,4,7-triketones and dihydrojasmone are also reported.
- Ballini, Roberto,Petrini, Marino,Marcantoni, Enrico,Rosini, Goffredo
-
p. 231 - 233
(2007/10/02)
-
- REGIOSELECTIVE HYDRATION OF ALKYNONES BY PALLADIUM CATALYSIS
-
Diketones are regioselectively prepared from alkynyl ketones under mild conditions by palladium catalysis; 5-heptyn-2-one and 2-(2-nonynyl)cyclohexanone give 1,4-diketones whereas 2-(2-heptynyl)cyclopentanone and 5,6-didehydroprostaglandin E2 methyl ester afford 1,5-diketones.
- Imi, Katsuharu,Imai, Kumiko,Utimoto, Kiitiro
-
p. 3127 - 3130
(2007/10/02)
-
- Addition of Aldehydes to Activated Double Bonds, XXXV. α-Keto Acids as an Equivalent for Aldehydes in the Thiazolium Salt-Catalyzed Addition
-
α-Keto acids can be used instead of aldehydes in the thiazolium salt-catalyzed addition to vinyl ketones.The yields of γ-diketones 1-7 resulting from the aliphatic α-keto acids are equivalent with those obtained from the aldehydes.The diketo acids 9-19 are prepared from the easily accessible 2-oxodiacids.Phenylpyruvic acids are easier to prepare than the phenylacetaldehydes and give better yields compared with the corresponding aldehydes in the addition to vinyl ketones leading to the γ-diketones 20-29.These diketones are converted to cyclopentenones.The dihydrofurylglyoxylic ester 40 leads to the diketone 43, which is converted to the diketone 44.There is no aldehyde known equivalent to that keto acid.
- Stetter, Hermann,Lorenz, Guenther
-
p. 1115 - 1125
(2007/10/02)
-
- UN ANION β-ACYLE MASQUE DANS LES REACTIONS D'ACYLATION: LE DERIVE LITHIE DU DIOXOLANNE DU LEVULATE DE TRIMETHYLSILYLE
-
An organolithium reagent derived form trimethylsilyl-4,4-ethylenedioxypentanoate reacts with mixed carboxylic-carbonic anhydrides as a homoenolate anion equivalent.Several monoethylene acetals of 1,4-diketones and the corresponding diketones are synthesized by this way.
- Moreau, Jean-Louis,Couffignal, Renee
-
p. 139 - 144
(2007/10/02)
-
- SYNTHESIS OF MONO- AND 1,4-DICARBONYL COMPOUNDS BASED ON THE OXYGENATION OF PHOSPHONATE CARBANIONS. SYNTHESIS OF DIHYDROJASMONE, ALLETHRONE AND METHYLENOMYCIN B
-
Oxidation of the α-alkylthio-substituted phosphonate carbanions was found to give the corresponding carbonyl compounds.A new synthesis of 1,4-dicarbonyl systems involving the oxygenation of phosphonate carbanions as a key step is described.Total synthesis of dihydrojasmone and allethrone and formal synthesis of methylenomycin B is reported.
- Mikolajczyk, Marian,Midura, Wanda,Grzejszczak, Slawomir
-
p. 2489 - 2492
(2007/10/02)
-
- DIRECT REMOTE OXIDATION OF ALIPHATIC KETONES TO γ- AND δ-DIKETONES
-
Aliphatic ketones are converted into γ- and δ-diketones in onepot oxidation reaction on treatment with Na2S2O8 in presence of Fe(II)ions.
- Nikishin, Gennady I.,Troyansky Emmanuil I.,Lazareva, Margarita I.
-
p. 4987 - 4988
(2007/10/02)
-
- The Synthesis of 1,4-Diketones via Fluoride-catalysed Michael Addition and Supported-permanganate-promoted Nef Transformation
-
A versatile synthetic route for the preparation of 1,4-diketones from simple starting materials is described and applied to the preparation of a wide range of diketones.The two most important steps in the reaction are the fluoride ion-catalysed Michael addition of a nitroalkane to a vinyl ketone and the subsequent transformation of the nitro ketone to the diketone using supported permanganate as the oxidant.The interaction of F- with nitroethane has been studied and a number of sources of F- have been tested in the Michael addition reaction.Potassium fluoride supported on alumina and potassium permanganate supported on silica gel are remarkably efficient reagents for the Michael addition and Nef transformation stages, respectively, although it is important to determine the best reagent loadings and drying conditions for maximum reaction efficiency to be achieved.
- Clark, James H.,Cork, David G.,Gibbs, Hugh W.
-
p. 2253 - 2258
(2007/10/02)
-
- Synthesis of 1,4-Diketones by Fluoride-catalysed Michael Addition and Supported Permanganate Oxidation
-
A wide variety of 1,4-diketones may be prepared from simple starting materials by using fluoride ion-catalysed Michael additions and silica gel-supported permanganate-promoted Nef transformations.
- Clark, James H.,Cork, David G.
-
p. 635 - 636
(2007/10/02)
-
- PREPARATION ET REACTIVITE DU DERIVE LITHIE ISSU DU DIOXOLANNE DU -CETO PENTANOATE DE TRIMETHYLSILYLE.
-
The organolithium reagent 4 issued from trimethylsilyl 4,4-ethylendioxypentanoate 3 reacts with ketones ; it affords β-hydroxy-acids 7 and β-ethylenic ketones 8.This reaction is an efficient route for carbonyl olefination. 4 also acts towards mixed carboxylic and carbonic anhydrides as a homoenolate equivalent.
- Moreau, Jean Louis,Couffignal, Rene
-
p. 5271 - 5274
(2007/10/02)
-
- Silyl Nitronates in Organic Synthesis. Routes to Heterocycles and Cyclopentanoids. Synthesis of Allethrolone and Calythrone. Acylation and Cyanohydroxylation of Double Bonds. An Exploratory Study
-
Silyl nitronates are versatile reagents for the preparation of heterocycles by dipolar addition to double bonds.The intermediate isoxazolidines can be transformed to 2-isoxazolines, isoxazoles, furans, dihydrofuranones, pyrazoles, pyridazines and pyridazones.Reduction of 2-isoxazolines with Ti3+ leads to hydroxylated 1,4-diketones, which subsequently can be cyclized to cyclopentenones.Routes to calythrone, rethrolones, prostanoids and a number of naturally occurring dihydrofuranones are devised, as well as synthetic procedures for acylation, preparation of endiones, hydroxyacylation, cyanation and hydroxycyanation of double bonds.
- Andersen, Soeren H.,Das, Nalin B.,Joergensen, Ruth D.,Kjeldsen, Gunhild,Knudsen, Jes S.,et al.
-
-
- Process for the preparation of ketones
-
The invention concerns a new process for the preparation of ketones; according to this process ketones are prepared from aldehydes and unsaturated compounds in the presence of bases using quaternary ammonium salts as catalysts.
- -
-
-