- Preparation of ketones from nitriles and phosphoranes
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The preparation of a ketone from a phosphorane and a nitrile is described. The workup conditions are mild, and the yields are high. The unreacted starting materials can easily be recovered.
- Taber, Douglass F.,Cai, Lisi
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Read Online
- Rhodium-Catalyzed Remote Isomerization of Alkenyl Alcohols to Ketones
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We develop herein an efficient rhodium-catalyzed remote isomerization of aromatic and aliphatic alkenyl alcohols into ketones. This catalytic process, with a commercially available catalyst and ligand ([RhCl(cod)]2 and Xantphos), features high efficiency, low catalyst loading, good functional group tolerance, a broad substrate scope, and no (sub)stoichiometric additive. Preliminary mechanistic studies suggest that this transformation involves an iterative dissociative β-hydride elimination-migration insertion process.
- Dong, Wenke,Yang, Hongxuan,Yang, Wen,Zhao, Wanxiang
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supporting information
(2020/02/28)
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- Photochemical oxidation of benzylic primary and secondary alcohols utilizing air as the oxidant
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A mild and green photochemical protocol for the oxidation of alcohols to aldehydes and ketones was developed. Utilizing thioxanthenone as the photocatalyst, molecular oxygen from air as the oxidant and cheap household lamps or sunlight as the light source, a variety of primary and secondary alcohols were converted into the corresponding aldehydes or ketones in low to excellent yields. The reaction mechanism was extensively studied.
- Nikitas, Nikolaos F.,Tzaras, Dimitrios Ioannis,Triandafillidi, Ierasia,Kokotos, Christoforos G.
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supporting information
p. 471 - 477
(2020/02/13)
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- Copper-Catalyzed Oxidative Fragmentation of Alkynes with NFSI Provides Aryl Ketones
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A copper-catalyzed oxidative cleavage reaction of alkynes using NFSI and TBHP was described. Various terminal and internal alkyne substrates were employed to render quick access to aryl ketone products in moderate to good yields. NFSI not only functioned as N-centered radical precursors but also engaged in the aryl group migration. Mechanistic studies also suggested the important role of water in the title reactions.
- Chen, Hanfei,Cheng, Hao,Huang, Yifan,Jin, Chaochao,Song, Weihan,Tan, Chen,Tan, Jiajing,Tang, Lin,Yang, Fang,Zhang, Shuaifei
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supporting information
(2020/11/03)
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- Visible-Light-Driven Epoxyacylation and Hydroacylation of Olefins Using Methylene Blue/Persulfate System in Water
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A visible-light-driven strategy for hydroacylation and epoxyacylation of olefins in water using methylene blue as photoredox catalyst and persulfate as oxidant is reported. In this unprecedented unified approach, two different transformations are accomplished using only one set of reagents. The method has a broad scope spanning a range of aromatic and aliphatic aldehydes as well as conjugated and nonconjugated olefins to deliver ketones and epoxyketones from abundant and inexpensive chemical feedstocks.
- De Souza, Gabriela F. P.,Bonacin, Juliano A.,Salles, Airton G.
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p. 8331 - 8340
(2018/07/21)
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- Palladium/NHC (NHC = N-Heterocyclic Carbene)-Catalyzed B-Alkyl Suzuki Cross-Coupling of Amides by Selective N-C Bond Cleavage
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A highly chemoselective, palladium-NHC (NHC = N-heterocyclic carbene)-catalyzed, direct cross-coupling between B-sp3-alkyl reagents and activated amides by N-C(O) cleavage is reported. Palladium-NHC precatalysts promote chemoselective alkylations of amides that are inaccessible by applying strong organometallic reagents. Various amides, including challenging primary amides after direct and site-selective N,N-di-Boc activation, are compatible with this method. The potential of this mild protocol is demonstrated in sequential C(sp2)-C(sp2)/C(sp2)-C(sp3) cross-couplings deploying a di-Boc amide derived from a common primary amide bond. The method provides a rare example of air- and moisture-stable, well-defined, and highly reactive Pd-NHC precatalysts in B-alkyl-Suzuki cross-couplings.
- Meng, Guangrong,Szostak, Michal
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supporting information
p. 6789 - 6793
(2018/11/21)
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- Reactivities of mixed organozinc and mixed organocopper reagents, 2. Selective n-alkyl transfer in tri-n-butylphosphine-catalyzed acylation of n-alkyl phenylzincs; an atom economic synthesis of n-alkyl aryl ketones
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Tri-n-butylphosphine-catalyzed acylation of mixed n-alkyl phenylzincs with aromatic acyl halides in THF is efficient in selective transfer of n-alkyl groups to produce n-alkyl aryl ketones in good yields. This route provides an atom economic organocatalyzed alternative to transition metal-catalyzed acylation of di-n-alkylzincs.
- Erdik, Ender,Pekel, ?zgen ?mür
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experimental part
p. 1501 - 1503
(2009/06/21)
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- Liquid-crystalline polymorphism of symmetrical azobananas: Bis(4-(4-alkylphenyl)azophenyl) 2-nitroisophtalates
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In this paper we present a series of novel compounds, bis(4-(4-alkylphenyl) azophenyl) 2-nitroisophtalates, which exhibit nematic and banana-type liquidcrystalline phases. The alkyl chain length varies from 1 to 18 carbons. The first ten members of this series exhibit nematic phase. The last eleven compounds exhibit banana-type liquid crystalline phases. The propyl and pentyl derivatives have extra second type of banana mesophase. Copyright Taylor & Francis Group, LLC.
- Zygadlo,Dardas,Nowicka,Hofmann,Galewski
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scheme or table
p. 283 - 291
(2011/08/02)
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- A New Solvent System for Recycling Catalysts for Chelation-Assisted Hydroacylation of Olefins with Primary Alcohols
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A new method to separate and reuse the catalyst system consisting of a rhodium complex and 2-aminopyridines for chelation-assisted hydroacylation was achieved using phenol and 4,4′-dipyridyl as the reaction medium, and 4-diphenylphosphinobenzoic acid as a ligand. Copyright
- Chang, Duck-Ho,Lee, Dae-Yon,Hong, Boo-Sun,Choi, Jun-Hack,Jun, Chul-Ho
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p. 424 - 425
(2007/10/03)
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- Novel Diradical-Mediated Ring Opening Reactions
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Thermo-isomerization of medium- and large-ring 1-phenylcycloalkanols 1e-i at around 650 deg C in a flow reactor system delivers the open-chain phenones 4e-i. A reaction mechanism via an open-chain diradical intermediate, followed by an intramolecular hydrogen transfer is proposed. Thermo-isomerization of α-substituted 1-phenylcyclododecanols 6 proceeds regioselectively under the formation of ω-substituted phenones 7. Furthermore, this novel hydrogen transfer reaction provides a new access to ω-substituted fatty acids.
- Rueedi, Georg,Nagel, Matthias,Hansen, Hans-Juergen
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p. 1210 - 1212
(2007/10/03)
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- Direct preparation of benzylic manganese reagents from benzyl halides, sulfonates, and phosphates and their reactions: Applications in organic synthesis
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The use of highly active manganese (Mn)*, prepared by the Rieke method, was investigated for the direct preparation of benzylic manganese reagents. The oxidative addition of the highly active manganese to benzylic halides was easily completed under mild conditions. Moreover, benzylic manganese sulfonates and phosphates were prepared by direct oxidative addition of Mn* to the carbon-oxygen bonds of benzylic sulfonates and phosphates. The resulting benzylic manganese reagents were found to undergo cross-coupling reactions with a variety of electrophiles. Most of these reactions were carried out in the absence of any transition metal catalyst under mild conditions. In addition, the use of highly active manganese was also studied for preparation of homo-coupled products of functionalized benzyl halides without transition metal catalysts. These useful approaches provided not only a facile synthetic route to the preparation of resoricinolic lipids but a facile synthesis of functionalized 4-benzylpyridines by regioselective and chemo selective γ-addition of benzylic group to N-alkoxycarbonylpyridinum salts.
- Suh, YoungSung,Lee, Jun-Sik,Kim, Seoung-Hoi,Rieke, Reuben D.
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- Solvent-free chelation-assisted hydroacylation of olefin by rhodium(I) catalyst under microwave irradiation
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A solvent-free protocol for the rhodium(I)-catalyzed intermolecular hydroacylation was achieved under microwave irradiation to furnish various ketones in high yields. The reactivity was improved by the addition of aniline as well as 2-amino-3-picoline and benzoic acid to induce a transimination, which facilitates the formation of intermediate aldimine. A comparison of the reactivity between the reaction performed under the conventional heating mode and the microwave irradiation using monomode reactor revealed an important specific microwave effect during the chelation-assisted hydroacylation. It is supposed that the observed specific microwave effect mainly originates from the formation of aldimine by condensation of aldehyde and amine, which leads to a development of charges in the transition state. This result confirms that the rate-determining step of the reaction is the initial condensation step rather than the subsequent hydroiminoacylation step.
- Loupy, Andre,Chatti, Saber,Delamare, Sarah,Lee, Dae-Yon,Chung, Jong-Hwa,Jun, Chul-Ho
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p. 1280 - 1285
(2007/10/03)
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- Effect of fluorine substituents on catalytic functionalizations of alkyl halides with organostannanes
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Introduction of fluorine atom(s) at the γ- and δ-positions of alkyl iodides increased the selectivities toward palladium-catalyzed cross-coupling reaction with organostannanes. A similar effect of fluorine substituents on the selectivities was also observed in the palladium-catalyzed carbonylative coupling reaction of alkyl iodides with phenyltributyltin under CO pressure.
- Shimizu, Rie,Fuchikami, Takamasa
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p. 6891 - 6894
(2007/10/03)
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- Solvent-free chelation-assisted intermolecular hydroacylation: Effect of microwave irradiation in the synthesis of ketone from aldehyde and 1-alkene by Rh(I) complex
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As a green alternative to classical homogeneous catalyst in toluene in closed vessels, the intermolecular hydroacylation of 1-alkenes with aldehydes by Rh(I) complex (Wilkinson catalyst) can be realized efficiently under solvent-free conditions. When coupled to microwave activation, it results in a serious improvement when compared to classical conditions.
- Jun, Chul-Ho,Chung, Jong-Hwa,Lee, Dae-Yon,Loupy, André,Chatti, Saber
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p. 4803 - 4805
(2007/10/03)
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- Aryl 1-chloroalkyl sulfoxides as acyl anion equivalents: A new synthesis of vinyl sulfides, ketones, and diketones from aryl 1-chloroalkyl sulfoxides and α,ω-dichloro-α,ω-disulfinylalkanes
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Treatment of aryl α-chloroalkyl sulfoxides, which were synthesized from aryl 1-chloroalkyl sulfoxides by alkylation with iodoalkanes, with trifluoroacetic anhydride and NaI in acetone at low temperature afforded vinyl sulfides in high yields. The vinyl sulfides were converted to ketones by hydrolysis with HClO4 in refluxing 1,4-dioxane in good yields. In this procedure, the lithiated aryl 1-chloroalkyl sulfoxides acted as acyl anion equivalents. The procedure was extended to a synthesis of α,ω-diketones starting from α,ω-dichloro-α,ω-disulfinylalkanes. The procedure was found to work well when the length of the carbon chain of the α,ω-disulfinylalkanes is longer than four, and the yields of the diketones were found to be somewhat variable (60-80%).
- Satoh, Tsuyoshi,Taguchi, Daisaku,Suzuki, Chihiro,Fujisawa, Satoshi
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p. 493 - 500
(2007/10/03)
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- C-H and C-C bond activation of primary amines through dehydrogenation and transimination
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Matrix presented Dehydrogenation and subsequent transimination of primary amines offer a new pathway for C-H bond activation, ortho-alkylation, and C-C bond activation to afford a variety of ketones in the reaction of 1-alkene by a cocatalyt system of Rh(I) and 2-amino-3-picoline.
- Jun, Chul-Ho,Chung, Kwan-Yong,Hong, Jun-Bae
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p. 785 - 787
(2007/10/03)
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- Preparation of ketones via the palladium-catalyzed cross-coupling of acid chlorides with trialkylboranes
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Trialkylboranes react with acid chlorides in the presence of palladium to generate alkyl and aryl ketones in good yields. (C) 2000 Elsevier Science Ltd.
- Kabalka, George W.,Malladi, Rama R.,Tejedor, David,Kelley, Shane
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p. 999 - 1001
(2007/10/03)
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- A new synthetic protocol for the direct preparation of organomanganese reagents; organomanganese tosylates and mesylates
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A new synthetic route to organomanganese sulfonate reagents has been developed. These useful reagents can be readily prepared via direct oxidative addition of highly reactive manganese to carbon-oxygen bonds of the corresponding tosylates and mesylates under mild conditions.
- Kim, Seung-Hoi,Rieke, Reuben D.
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p. 4931 - 4934
(2007/10/03)
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- Catalytic transformation of aldimine to ketimine by Wilkinson's complex through transimination
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(equation presented) The C-H bond activation in homogeneous catalysis is important for carbon skeleton construction through C-C bond formation. In this report, a new direct synthesis of ketimine from aldimine bearing no coordination site is demonstrated with high catalytic efficiency. Transimination is the major role for this catalytic reaction.
- Jun, Chul-Ho,Hong, Jun-Bae
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p. 887 - 889
(2008/02/10)
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- Direct formation of organomanganese bromides using Rieke manganese
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The direct formation of organomanganese bromides can be accomplished under mild conditions from the direct oxidative addition to Rieke manganese to alkyl and thienyl bromides.
- Kim, Seung-Hoi,Hanson, Mark V.,Rieke, Reuben D.
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p. 2197 - 2200
(2007/10/03)
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- Reaction of I2 with α-boraalkylmagnesium bromide: A new synthesis of mixed alkyl secondary alcohols
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1,1-Diborylalkanes, prepared through hydroboration of 1-alkynes using BH3:N(C2H5)2Ph complex, on reaction with Grignard reagent followed by I2/NaOH treatment and H2O2/OH- oxidation give the corresponding mixed alkyl secondary alcohols.
- Kishan Reddy,Periasamy
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p. 8877 - 8886
(2007/10/02)
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- Synthesis and Liquid Crystalline Properties of 1-(trans-4-Alkylcyclohexylethyl)-4-Alkyl- and -4-Alkoxy-Benzenes, Their Ketone Precursors, and Some Lateral Fluoro-Derivatives
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The preparation of some 1-(trans-4-alkylcyclohexylethyl)-4-alkyl- and -4-alkoxy-benzenes, their methylenecarbonyl linked analogues and their laterally fluoro- and bromo-substituted derivatives is reported.Twenty-four inter-related compounds have been prepared and the trends in their transition temperatures are discussed.Both the melting points and clearing points for these compounds are relatively low and, in general, SB and SA phases predominate.The suitability of these compounds as additives to SC materials has been assessed using two SC hosts.Keywords: Mesogenic cyclohexylethanes, mesogenic ketones, fuoro-substitution of mesogens
- Gray, George W.,Lacey, David,Scrowston, Richard M.,Shenouda, Ibrahim G.,Toyne, Kenneth J.
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p. 101 - 116
(2007/10/02)
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- Oxidation of sec-Alcohols to the Corresponding Ketones by Corynebacterium equi
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Corinebacterium equi IFO 3730 was found to oxidize a wide variety of sec-alcohols, including alkanols, substituted alkanols, alkenols and cyclic alcohols, in moderate to high yields.Among them, the sec-alcohols which have longer carbon chains were oxidized more smoothly than those with smaller numbers of carbon.Although both enantiomers of unsymmetrically disubstituted carbinols were oxidized, the S form of 2-dodecanol was converted to the corresponding ketone a little faster than the other enantiomer.
- Ohta, Hiromichi,Fujiwara, Hidenori,Tsuchihashi, Gen-ichi
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p. 1509 - 1516
(2007/10/02)
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