- The radical-chain addition of aldehydes to alkenes by the use of N-hydroxyphthalimide (NHPI) as a polarity-reversal catalyst
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Hydroacylation of simple alkenes with aldehydes via a radical process was successfully achieved by the use of N-hydroxyphthalimide (NHPI) as a polarity-reversal catalyst. Thus, 5-tridecanone was obtained by the reaction of oct-1-ene with pentanal in the presence of small amounts of NHPI and dibenzoyl peroxide (BPO).
- Tsujimoto,Iwahama,Sakaguchi,Ishii
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Read Online
- Sodium Bromide-Catalyzed Oxidation of Secondary Benzylic Alcohols Using Aqueous Hydrogen Peroxide as Terminal Oxidant
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A halide salt, hydroperoxide and AcOH catalyst system was applied to the oxidation of secondary benzylic alcohols. This simple system can be applied to a variety of secondary benzylic alcohols and scaled up for gram-scale preparation. High secondary benzylic alcohol selectivity of the present method is demonstrated in hydroxyketone synthesis. Based on several experimental results, a catalytic cycle for our oxidation is proposed.
- Komagawa, Hiromi,Maejima, Yukako,Nagano, Takashi
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supporting information
p. 789 - 793
(2016/03/09)
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- Borohydride-mediated radical addition reactions of organic iodides to electron-deficient alkenes
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Cyanoborohydrides are efficient reagents in the reductive addition reactions of alkyl iodides and electron-deficient olefins. In contrast to using tin reagents, the reaction took place chemoselectively at the carbon-iodine bond but not at the carbon-bromine or carbon-chlorine bond. The reaction system was successfully applied to three-component reactions, including radical carbonylation. The rate constant for the hydrogen abstraction of a primary alkyl radical from tetrabutylammonium cyanoborohydride was estimated to be 4 M-1 s-1 at 25 °C by a kinetic competition method. This value is 3 orders of magnitude smaller than that of tributyltin hydride.
- Kawamoto, Takuji,Uehara, Shohei,Hirao, Hidefumi,Fukuyama, Takahide,Matsubara, Hiroshi,Ryu, Ilhyong
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p. 3999 - 4007
(2014/05/20)
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- Stereospecific construction of chiral tertiary and quaternary carbon by nucleophilic cyclopropanation with bis(iodozincio)methane
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The reaction of a ketone having a leaving group at the aposition, such as a,bepoxy ketone or asulfonyloxy ketone, with bis(iodozincio) methane affords a zinc alkoxide of cyclopropanol. The reaction proceeds by nucleophilic addition of the dizinc to the carbonyl group and a sequential intramolecular nucleophilic substitution of the introduced iodozinciomethyl group to the adjacent electrophilic carbon that has a leaving group. When an optically active a,β-epoxy ketone or asulfonyloxy ketone is treated with the dizinc, a zinc alkoxide of cyclopropanol having a chiral tertiary or quaternary carbon in the cyclopropane ring is obtained, and the obtained zinc alkoxide of cyclopropanol acts as a chiral ho-moenolate. When it is treated with an electrophile in the presence of copper cyanide, it gives an optically active a-tertiary or -quaternary ketone that retains high optical purity.
- Nomura, Kenichi,Matsubara, Seijiro
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supporting information; experimental part
p. 147 - 152
(2010/04/23)
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- Tin-free giese reaction and the related radical carbonylation using Alkyl iodides and cyanoborohydrides
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Tin-free Giese reaction and the related radical carbonylation process proceeded efficiently in the presence of sodium cyanoborohydride and tetrabutylammonium cyanoborohydride. The reaction took place chemoselectively at the carbon-iodine bond but not at the carbon-bromine and carbon-chlorine bonds. The iodine atom transfer followed by hydride reduction of the resulting carbon-iodine bond is proposed as a possible mechanism.
- Ryu, Ilhyong,Uehara, Shohei,Hirao, Hidefumi,Fukuyama, Takahide
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body text
p. 1005 - 1008
(2009/04/07)
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- Preparation of zinc-homoenolate from α-sulfonyloxy ketone and bis(iodozincio)methane
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Treatment of α-sulfonyloxy ketone with bis(iodozincio)-methane gives a zinc cyclopropoxide which is formed via a nucleophilic addition of the reagent to carbonyl group followed by an intramolecular substitution reaction. Copyright
- Nomura, Kenichi,Matsubara, Seijiro
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p. 164 - 165
(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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- Efficient ruthenium-catalyzed aerobic oxidation of alcohols using a biomimetic coupled catalytic system
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Efficient aerobic oxidation of alcohols was developed via a biomimetic catalytic system. The principle for this aerobic oxidation is reminiscent of biological oxidation of alcohols via the respiratory chain and involves selective electron/proton transfer. A substrate-selective catalyst (ruthenium complex 1) dehydrogenates the alcohol, and the hydrogens abstracted are transferred to an electron-rich quinone (4b). The hydroquinone thus formed is continuously reoxidized by air with the aid of an oxygen-activating Co-salen type complex (6). Most alcohols are oxidized to ketones in high yield and selectivity within 1-2 h, and the catalytic system tolerates a wide range of O2 concentrations without being deactivated. Compared to other ruthenium-catalyzed aerobic oxidations this new catalytic system has high turnover frequency (TOF).
- Csjernyik, Gabor,Ell, Alida H.,Fadini, Luca,Pugin, Benoit,Baeckvall, Jan-E.
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p. 1657 - 1662
(2007/10/03)
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- Catalytic activation of C-H and C-C bonds of allylamines via olefin isomerization by transition metal complexes
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(matrix presented) The metal-catalyzed reaction of olefins with allylamines bearing coordination sites (2-pyridyl groups) was studied. With Ru3(CO)12 as catalyst, activation of C-H bonds led to the formation of ketimines that were hydrolyzed to give asymmetric ketones. With [(C8H14)2RhCl]2, both C-H and C-C bonds were activated and symmetric ketones were formed on hydrolysis. The reaction involves double bond migration of the allylamine to form an aldimine.
- Jun, Chul-Ho,Lee, Hyuk,Park, Jae-Bum,Lee, Dae-Yon
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p. 2161 - 2164
(2008/02/11)
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- Arene-catalysed lithiation of triflates and triflamides under Barbier-type conditions: An indirect transformation of alcohols and amines into organolithium compounds
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The reaction of alkyl triflates 1 or benzyl triflamides 3 with an excess of lithium powder and a catalytic amount of naphthalene (4 mol%) in the presence of different electrophiles [Me3SiCl, Pr(i)CHO, Bu(t)CHO, PhCHO, 4-MeOC6H4-CHO, CH3(CH2)6CHO, Et2CO, (CH2)5CO, (c-C3H5)2CO, PhCOMe, 4-MeC6H4COPh, PhCh=NPh, n-C8H7CON(CH2)4] in THF at temperature ranging between -78 and 0°C leads, after hydrolysis with water, to the corresponding condensation products 2. When α,β-unsaturated carbonyl compounds are used as electrophilic compounds 1,2- (3-cyclohexenone) or 1,4-addition (cinnamaldehyde or benzylideneacetone) takes place depending on the electrophile used.
- Alonso, Emma,Ramon, Diego J.,Yus, Miguel
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p. 14341 - 14348
(2007/10/03)
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- Synthesis of undecan-3-one; (+/-) frontalin; (+/-)-endo-, and (+/-)-exo-brevicomin under sonochemical aqueous conditions
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Conjugate addition of 1-bromohexane (1) to 2-penten-3-one under sonochemical aqueous conditions, using Zn/Cu catalyst give undecan-3-one (3).Also, Zn-Cu catalysed conjugate addition of 1-bromo-2-methylpropene to 3-buten-2-one yield 6-methyl-6-hepten-2-one (6), which is tailored to furnish (+/-)-frontalin (7).Similarly, conjugate addition of 1-bromo-2-pentenes (8 and 8a) to 3-buten-2-one afford Z-6-nonen-2-one (9) and E-6-nonen-2-one (9a) respectively.An ice-cooled solution of 9/9a on tretament with m-chloroperbenzoic acid give (+/-)-exo-(10) and (+/-)-endo-brevicomin (10a) respectively.
- Trehan, I. R.,Singh, Jasvinder,Arora, Ajay K.,Kaur, Jasamrit,Kad, G. L.
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p. 396 - 398
(2007/10/03)
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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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p. 121 - 124
(2007/10/02)
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- Reaction of acylsilanes with sulfur ylides. Selective formation of silyl enol ethers or β-ketosilanes
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The reaction of acylsilanes with sulfur ylides in THF results in the formation of the corresponding silyl enol ethers or β-ketosilanes. The relative ratio of these products varies with the ylide conditions and the stability of ylide used. It is noteworthy that silyl enol ethers were formed under the salt-free ylide conditions, and that β-ketosilanes were yielded in the presence of soluble inorganic salts in THF, selectively. The formation of both products would be interpreted in terms of the anionotropic and cationotropic rearrangements of silyl group in the reaction intermediate.
- Nakajima, Tadashi,Segi, Masahito,Sugimoto, Fumitosi,Hioki, Reiko,Yokota, Seiko,Miyashita, Kiyoshi
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p. 8343 - 8358
(2007/10/02)
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- Hindered organoboron groups in organic chemistry. 24. The condensation of aliphatic aldehydes with dimesitylboron stabilised carbanions to give ketones
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The condensation of boron stabilised carbanions, MeS2BCHLiR1, (R1≠H) with aliphatic aldehydes, R2CHO, followed by treatment with trifluoroacetic anhydride (TFAA) or N-chlorosuccinimide (NCS) is an unique, broadly applicable redox process that yields ketones, R1CH2COR2, directly and in high yields. The anion MeS2BCH2Li (MeS2BCHLiR1, R1=H) gives high yields of alkenes, R2CH=CH2 in the same conditions.
- Pelter, Andrew,Smith, Keith,Elgendy, Said M. A.,Rowlands, Martin
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p. 7104 - 7118
(2007/10/02)
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- Diorganomagnesium Compounds from Magnesium, Hydrogen, and 1-Alkenes and Their Application in Synthesis
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1-Alkenes are converted in high yields to the corresponding primary diorganomagnesium compounds by transition metal-catalyzed hydromagnesation reaction using catalytically prepared suspended (MgH2*) or dissolved magnesium hydride (MgH2').The most active hydromagnesation catalysts have been found to be combinations of zirconium tetrahalides with MgH2* or MgH2'.The reaction is highly regio- and chemoselective.The diorganomagnesium compounds prepared in situ from magnesium, hydrogen, and 1-alkenes can be applied to the synthesis of organic and organometallic compounds just as Grignard compounds (Scheme 3, reactions 3-11).Dioctylmagnesium undergoes the growth reaction with ethene in the presence of quinuclidine and is oxidized by molecular oxygen in high yield to 1-octanol. Key Words: Magnesium hydride, catalytically prepared / Hydromagnesation reactions / Magnesium, diorgano compounds, preparation from magnesium, hydrogen and 1-alkenes / Magnesium, diorgano compounds, application in syntheses / Magnesium, diorgano compounds, oxidation of
- Bogdanovic, Borislav,Bons, Peter,Konstantinovic, Stanimir,Schwickardi, Manfred,Westeppe, Uwe
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p. 1371 - 1384
(2007/10/02)
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- HINDERED ORGANOBORON GROUPS IN ORGANIC SYNTHESIS. 13. THE DIRECT PRODUCTION OF KETONES FROM ALIPHATIC ALDEHYDES BY A UNIQUE VARIANT OF THE BORON-WITTIG REACTION
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In the presence of trifluoroacetic anhydride or N-chlorosuccinimide, aliphatic aldehydes react with dimesitylboron stabilised carbanions to give after work up, the corresponding ketones, a process wich is unique among Wittig type reactions.Yields of ketones are satisfactory in all cases except those involving the anion derived from the parent compound dimesitylmethylborane, wich give the corresponding alkenes.
- Pelter, Andrew,Smith, Keith,Elgendy, Said,Rowlands, Martin
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p. 5643 - 5646
(2007/10/02)
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- Cr(III) or Ce(IV) Impregnated Perfluorinated Resin-Sulfonic Acid Catalyst for the Oxidation of Alcohols
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Sereval polymer supported catalysts are prepared by treatment of Nafion 551 (abbreviated NAFK below) with metal salts.Cr/NAFK and Ce/NAFK found to be effective catalysts for the dehydrogenative oxidation of alcohols to the corresponding ketones by means of t-butyl hydroperoxide.Selective oxidation of secondary alcohols in the presence of primary ones was performed using a Ce/NAFK-NaBrO3 system.
- Kanemoto, Shigekazu,Saimoto, Hiroyuki,Oshima, Koichiro,Utimoto, Kiitiro,Nozaki, Hitosi
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p. 519 - 523
(2007/10/02)
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- A Convenient and Efficient Unsymmetrical Ketone Synthesis from Acid Chlorides and Alkyl Iodides Catalyzed by Palladium
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Unsymmetrical ketones are prepared in good or excellent yields by a palladium catalyzed coupling reaction of acid chlorides and alkyl iodides meditated by Zn-Cu couple.
- Tamaru, Yoshinao,Ochiai, Hirofumi,Sanda, Fumio,Yoshida, Zen-ichi
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p. 5529 - 5532
(2007/10/02)
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- Cr(III) OR Ce(IV) IMPREGNATED PERFLUORINATED RESIN-SULFONIC ACID CATALYSTS FOR THE OXIDATION OF ALCOHOLS
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Several polymer supported catalysts are prepared by treatment of NafionR 511 (abbreviated as NAFK below) with metal salts and found to be effective in promoting the dehydrogenative oxidation of alcohols with tBuOOH.
- Kanemoto, Sigekazu,Saimoto, Hiroyuki,Oshima, Koichiro,Nozaki, Hitosi
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p. 3317 - 3320
(2007/10/02)
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- Nonrandomization of Energy in Chemically Activated 2-Butanone Ions
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Both CH3CH2C(=+OH)C.H2 and CH3C.HC(=+OH)CH3 isomerize to 2-butanone ion and than lose methyl or ethyl in the mass spectrometer.More translational energy is released in the loss of methyl from CH3CH2C(=+OH)C.H2 than from CH3C.HC(=+OH)CH3, while the energies released in the losses of ethyl are in the opposite order.The opposite order of energies released is attributed to nonrandomization of energy in the 2-butanone ion formed from at least one of its enol isomers.The nonrandom energy distribution would have to be created in the first of the two steps in the rearrangement to the 2- butanone ion, and so may survive a second izomerization.
- McAdoo, David J.,Hudson, Charles E.
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p. 2451 - 2454
(2007/10/02)
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- ADDITION RADICALAIRE DU PROPANAL A DIVERS ALCENES ET CYCLENES : ASPECTS STERIQUES ET POLAIRES
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Free radical addition of propanal to double bonds, initiated by benzoyl peroxide, mainly leads to two adducts, an aldehyde and a ketone, when the double bond has a methylene group ; these results are explained in terms of polar effects in the free radical transfert reactions.When the double bond has no methylene group, only the ketonic adduct is obtained ; the steric effects in the free radical addition step explain these results.
- Tabbaa, I.,Cazaux, M.,Lalande, R.
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p. 1011 - 1018
(2007/10/02)
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- A REGIOSPECIFIC SYNTHESIS OF TRIMETHYLSILYL ENOL ETHERS USING RHODIUM CATALYZED ISOMERIZATION OF β-TRIMETHYLSILYLALLYL ALCOHOLS
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The rhodium catalyzed isomerization of β-trimethylsilylallyl alcohols has been successfully applied for the regiospecific synthesis of trimethylsilyl enol ethers.
- Matsuda, Isamu,Sato, Susumu,Izumi, Yusuke
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p. 2787 - 2790
(2007/10/02)
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- PREPARATION AND SYNTHTETIC UTILITY OF CYCLOPROPYL PHENYL SULFIDES
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Primary alkyl halides and epoxides react with 1-lithiocyclopropyl phenyl sulfide to give derivatives suitable for transformation to carbonyl compounds or for desulfurization.
- Bumgardner, C. L.,Lever, J. R.,Purrington, S. T.
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p. 2379 - 2382
(2007/10/02)
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