- A new and one-pot synthesis of α,β-unsaturated ketones by dehydrogenation of various ketones with n-tert-butyl phenylsulfinimidoyl chloride
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α,β-Unsaturated ketones were synthesized by one-pot procedure from various ketones in good to excellent yields on treatment of their lithium enolates with N-tert-butyl phenylsulfinimidoyl chloride (1) under mild conditions.
- Mukaiyama, Teruaki,Matsuo, Jun-Ichi,Kitagawa, Hideo
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- Enantioselective N -Alkylation of Nitroindoles under Phase-Transfer Catalysis
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An asymmetric phase-transfer-catalyzed N -alkylation of substituted indoles with various Michael acceptors was studied. Acidities of nitroindoles were determined in acetonitrile by UV-Vis spectrophotometric titration. There was essentially no correlation between acidity and reactivity in the aza-Michael reaction. The position of the nitro group on the indole ring was essential to control the stereoselectivity of the reaction. Michael adducts were obtained in high yields and moderate enantioselectivities in the reaction between 4-nitroindole and various Michael acceptors in the presence of cinchona alkaloid based phase-transfer catalysts. In addition to outlining the scope and limitations of the method, the geometries of the transition states of the reaction were calculated.
- Erkman, Kristin,J?rving, Ivar,K?ster, Kristjan,Kanger, T?nis,Leito, Ivo,Mart?nova, Jevgenija,Metsala, Andrus,Saame, Jaan,Trubits?n, Dmitri
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p. 1047 - 1059
(2020/04/01)
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- Organocatalytic Enantioselective Selenosulfonylation of a C-C Double Bond to Form Two Stereogenic Centers in an Aqueous Medium
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Organocatalytic selenosulfonylation of the C-C double bond of α,β-unsaturated ketones to construct two contiguous stereogenic centers in an aqueous medium was described. A series of α-selenyl and β-sulfonyl ketones with various functional groups were synthesized in good yields and enantioselectivities with saturated NaCl solution as the solvent. In addition, this protocol had been successfully scaled up to a decagram scale via a simple workup procedure.
- Chen, Zhili,Hu, Fangli,Huang, Shengli,Zhao, Zhengxing,Mao, Hui,Qin, Wenling
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p. 8100 - 8111
(2019/06/17)
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- Synthesis of Enones and Enals via Dehydrogenation of Saturated Ketones and Aldehydes
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A general, efficient and economic palladium-catalyzed dehydrogenation to form enones or enals has been developed. The approach possesses extremely broad substrate scope including various linear or cyclic saturated ketones and aldehydes. The protocol is ligand-free, and molecular oxygen is used as the sole clean oxidant in the reaction. Due to mild reaction conditions, good functional group compatibility, and versatile utilities of enones and enals, the method can be applied in the late-stage synthesis of natural products, pharmaceuticals and fine chemicals. (Figure presented.).
- Pan, Gao-Fei,Zhu, Xue-Qing,Guo, Rui-Li,Gao, Ya-Ru,Wang, Yong-Qiang
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p. 4774 - 4783
(2018/11/10)
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- An iron-catalyzed hydroalkylation reaction of α,β-unsaturated ketones with ethers
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A general strategy for the hydroalkylation of vinyl ketones using ethers catalyzed by an iron catalyst is described. This catalytic method permits direct transformation of easily accessible and abundant precursors into highly substituted, structurally diverse and functionally concentrated products.
- Lan, Yun,Fan, Pei,Liu, Xiao-Wei,Meng, Fei-Fan,Ahmad, Tanveer,Xu, Yun-He,Loh, Teck-Peng
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supporting information
p. 12353 - 12356
(2017/11/20)
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- Photoredox-Catalyzed Cyclopropanation of Michael Acceptors
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A new protocol for the catalytic cyclopropanation of α,β-unsaturated carbonyl compounds with diiodomethane by means of photoredox catalysis has been successfully developed. The transformation is characterized by its mild conditions, functional-group compatibility, and excellent selectivity profile.
- del Hoyo, Ana M.,García Suero, Marcos
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supporting information
p. 2122 - 2125
(2017/04/24)
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- Carbonylative coupling of allylic acetates with aryl boronic acids
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The first allylic carbonylation reaction of allylic acetates with aryl boronic acids under carbon monoxide has been developed. Using Pd-PCy3 as a catalyst, a wide spectrum of allylic acetates was carbonylated in the presence of various aryl boronic acids, affording α,β-unsaturated aryl ketones in good to excellent yields. Preliminary studies indicate that carbon monoxide always inserts at the least substituted terminal allylic carbon and the resulting β,γ-unsaturated aryl ketones generally isomerise to the ketones obtained.
- Ma, Wei,Xue, Dong,Yu, Ting,Wang, Chao,Xiao, Jianliang
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supporting information
p. 8797 - 8800
(2015/05/20)
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- Trans-cis isomerization of vinylketones through triplet 1,2-biradicals
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The irradiation of trans-vinylketones 1a-c yields the corresponding cis isomers 2a-c. Laser flash photolysis of 1a and 1b with 308 and 355 nm lasers results in their triplet ketones (T1K of 1), which rearrange to form triplet 1,2-biradicals 3a and 3b, respectively, whereas irradiation with a 266 nm laser produces their cis-isomers through singlet reactivity. Time-resolved IR spectroscopy of 1a with 266 nm irradiation confirmed that 2a is formed within the laser pulse. In comparison, laser flash photolysis of 1c with a 308 nm laser showed only the formation of 2c through singlet reactivity. At cryogenic temperatures, the irradiation of 1 also resulted in 2. DFT calculations were used to aid in the characterization of the excited states and biradicals involved in the cis-trans isomerization and to support the mechanism for the cis-trans isomerization on the triplet surface.
- Ranaweera, R. A. A. Upul,Scott, Tianeka,Li, Qian,Rajam, Sridhar,Duncan, Alexander,Li, Rui,Evans, Anthony,Bohne, Cornelia,Toscano, John P.,Ault, Bruce S.,Gudmundsdottir, Anna D.
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p. 10433 - 10447
(2015/03/14)
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- Synthesis and properties of BF2-3,3′- dimethyldiarylazadipyrromethene near-infrared fluorophores
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The first synthesis of both organic and aqueous soluble BF2 chelated 3,3′-dimethyl-5,5′-diarylazadipyrromethenes has been achieved. The fluorophores are emissive in organic and aqueous solvents with high quantum yields in the key biological near-infrared (NIR) spectral region of 675-700 nm. Following efficient cellular uptake from aqueous media the fluorophore can be readily visualized with confocal microscopy.
- Wu, Dan,O'Shea, Donal F.
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p. 3392 - 3395
(2013/07/26)
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- Synthesis of Z-alkenes from Rh(I)-catalyzed olefin isomerization of β,γ-unsaturated ketones
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Developing olefin isomerization reactions to reach kinetically controlled Z-alkenes is challenging because formation of trans-alkenes is thermodynamically favored under the traditional catalytic conditions using acids, bases, or transition metals as the catalysts. A new synthesis of Z-alkenes from Rh(I)-catalyzed olefin isomerization of β,γ-unsaturated ketones to α,β-unsaturated ketones was developed, providing an easy and efficient way to access various Z-enones.
- Zhuo, Lian-Gang,Yao, Zhong-Ke,Yu, Zhi-Xiang
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supporting information
p. 4634 - 4637
(2013/10/08)
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- PROTEIN CROSSLINKING INHIBITOR AND USE OF THE SAME
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The present invention relates to: a ketone compound having transglutaminase-inhibiting activity, which is represented by the following Formula 1, 2, or 3: wherein R1 is a substituted or unsubstituted aryl or heterocyclyl group, R2, R3, and R4 are hydrogen atoms, n is 2, X is halogen, R5 and R6 independently represent a hydrogen atom or a substituted or unsubstituted C1-C10 alkyl, aryl, or aralkyl group, wherein R5 and R6 are not hydrogen atoms at the same time, or R5 and R6 may be taken together to form a saturated or unsaturated and substituted or unsubstituted heterocyclyl group containing a nitrogen atom (N); an inhibitor of protein crosslinking comprising the compound; and a composition for preventing or treating a protein-crosslinking causative disease, which comprises the compound or the protein crosslinking inhibitor.
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Page/Page column 29
(2012/11/08)
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- Decarboxylative allylation of glyoxylic acids with diallyl carbonate
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A catalyst system consisting of Pd(PPh3)4 and P(pTol)3 was found to effectively promote the intermolecular decarboxylative coupling of α-oxocarboxylic acids with diallyl carbonate to give α,β-unsaturated ketones. The key advantage of the new reaction protocol is that preformation of the allyl esters is not required. The reaction is believed to proceed via phosphane-mediated decarboxylation of the α-oxocarboxylates, leading to acyl anion equivalents that are allylated within the coordination sphere of the palladium catalyst. Under the reaction conditions, the double bond then migrates into conjugation with the carbonyl group. Copyright
- Manjolinho, Filipe,Gruenberg, Matthias F.,Rodriguez, Nuria,Goossen, Lukas J.
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supporting information; experimental part
p. 4680 - 4683
(2012/10/08)
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- InCl3/Me3SiCl-catalyzed direct michael addition of enol acetates to α,β-unsaturated ketones
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The direct Michael addition of enol acetates to α,β-unsaturated ketones was achieved using a combination of Lewis acid catalysts, InCl 3 and Me3SiCl, which furnished stable enol-form products that could be further transformed into functionalized 1,5-diketones by reactions with various electrophiles.
- Onishi, Yoshiharu,Yoneda, Yuki,Nishimoto, Yoshihiro,Yasuda, Makoto,Baba, Akio
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p. 5788 - 5791
(2013/01/15)
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- A one-pot oxidation/allylation/oxidation sequence for the preparation of β,γ-unsaturated ketones directly from primary alcohols
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A one-pot oxidation/allylation/oxidation procedure has been developed for the conversion of primary alcohols into β,γ-unsaturated ketones. The methodology has been applied to a range of alcohols, and in some cases, isomerisation to produce the corresponding α,β-unsaturated ketones has been carried out.
- Moody, Catherine L.,Pugh, David S.,Taylor, Richard J.K.
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p. 2511 - 2514
(2011/05/09)
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- Asymmetric hydrocyanation of α,β-unsaturated ketones into β-cyano ketones with the [Ru(phgly)2(binap)]/C6H 5OLi catalyst system
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Enantioselective conjugate addition of HCN to α,β-unsaturated ketones catalyzed by the combined system of [Ru{(S)-phgly}2{(S)- binap}] and C6H5OLi has afforded β-cyano ketones in high yield (see scheme). No detectable amount of the corresponding 1,2-adduct was produced and tert-C4H9OCH3 was the solvent of choice. The cyanation was conducted with a substrate-to-catalyst molar ratio in the range of 200:1-1000:1 at -20-0°C. Copyright
- Kurono, Nobuhito,Nii, Noriyuki,Sakaguchi, Yusuke,Uemura, Masato,Ohkuma, Takeshi
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p. 5541 - 5544
(2011/07/08)
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- Structural study-guided development of versatile phase-transfer catalysts for asymmetric conjugate additions of cyanide
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Unprecedented phase-transfer catalysts for the first example of an organocatalytic asymmetric conjugate addition of cyanide with acetone cyanohydrin are reported (see scheme). Utilizing an accessible cupreidinium salt and a cyanation reagent suitable for industrial scale, this reaction holds significant promise for practical asymmetric synthesis. The catalysts were developed as a result of key structural insights gained by X-ray analysis. Copyright
- Provencher, Brian A.,Bartelson, Keith J.,Liu, Yan,Foxman, Bruce M.,Deng, Li
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p. 10565 - 10569
(2011/12/05)
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- Ru- and Pd-catalysed synthesis of 2-arylfurans by one-flask heck arylation/oxidation
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2,5-Disubstituted furans were synthesized by one-flask Heck arylation/oxidation sequences. The starting materials are 2-substituted 2,3-dihydrofurans, conveniently available by RCM/isomerization sequences, and arenediazonium salts. These react in ligand-free Heck reactions to afford 2,5-disubstituted 2,5-dihydrofurans, which are oxidized to the corresponding furans without isolation or intermediate workup. The oxidation is conveniently achieved with chloranil or DDQ, depending on the substrate.
- Schmidt, Bernd,Geissler, Diana
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p. 4814 - 4822
(2011/10/09)
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- Expedient synthesis and solvent dependent oxidation behavior of a water-soluble IBX derivative
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IBX derivative 6, synthesized in two steps from 2-aminoterephthalic acid, 8, is soluble in both DMF and water. A variety of alcohols are oxidized using 6 in DMF with ease and selectivity identical to that of parent IBX. However, oxidations carried out in water and other aqueous solvent mixtures using 6 exhibit unique selectivities toward different substrates and provide products different from reactions carried out in DMF. A mechanistic rationale is provided for this solvent dependent behavior of 6.
- Kommreddy, Amitha,Bowsher, Michael S.,Gunna, Meena R.,Botha, Kirankumar,Vinod, Thottumkara K.
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p. 4378 - 4382
(2008/12/21)
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- Difluoro-λ3-bromane-induced oxidative carbon-carbon bond-forming reactions: Ethanol as an electrophilic partner and alkynes as nucleophiles
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Reported here for the first time are the oxidative couplings of alkynes and primary alcohols yielding conjugated enones. Although the BF3-catalyzed reaction of terminal alkynes with p-trifluoromethylphenyl(difluoro)-λ3-bromane results in the fluoro-λ3-bromanation of triple bonds to afford (E)-β-fluorovinyl-λ3-bromanes, reaction of an alkyne with the difluoro-λ3-bromane in the presence of an alcohol and BF3-Et2O affords directly conjugated enones in good yields. The reaction proceeds in a highly stereo- and regioselective manner under metal-free conditions. Interestingly, no formation of enones was detected, when difluoro-λ3-iodane p-CF3C6H4IF2 was used instead of the λ3-bromane. A mechanism involving a λ3-bromane-induced oxidation of an alcohol to an aldehyde, [2 + 2] cyclization with alkynes yielding 2H-oxetes, and finally the electrocyclic ring opening is discussed. Copyright
- Ochiai, Masahito,Yoshimura, Akira,Mori, Takeshi,Nishi, Yoshio,Hirobe, Masaya
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p. 3742 - 3743
(2008/09/21)
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- A New Synthesis of Butadienyl- and Styrylboronic Esters: Highly Reactive Intermediates for Suzuki Cross-Coupling
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(Matrix Presented) Alkoxy-functionalized butadienyl- and styrylboronic esters have been synthesized starting from α,β-unsaturated acetals. These derivatives readily cross-couple with aryl substrates, and the obtained products can be transformed under mild
- Tivola, Paolo Balma,Deagostino, Annamaria,Prandi, Cristina,Venturello, Paolo
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p. 1275 - 1277
(2007/10/03)
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- Palladium catalyzed coupling reaction of acylchromate complexes and allylic bromides
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A cross-coupling reaction between acylchromate complexes and allylic bromides takes place under CO atmosphere in the presence of a catalytic amount of Pd(PPh3)4 to afford the corresponding allylic ketones in good yield. The same reaction also proceeds by adding RNC under argon atmosphere in place of CO atmosphere. Thus, the acylchromate complex works as a good acyl donor for Pd catalyzed acylation reaction.
- Sakurai, Hidehiro,Tanabe, Katsuhiko,Narasaka, Koichi
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p. 309 - 310
(2007/10/03)
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- The design of diastereoselective Mukaiyama-Michael reaction of ketene silyl acetal
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The highly diastereoselective Mukaiyama-Michael reaction has been designed. Suppression of an electron-transfer process is crucial for this purpose and the following conditions should be satisfied. (1) TiCl4 is employed as a Lewis acid. (2) Ketene silyl acetals have bulky siloxy and/or alkoxy group(s). (3) α-Enones have a bulky acyl group. The excellent syn- selectivity up to a 99:1 ratio is attained under these conditions. The selectivity is reversed to the anti-preference upon decreasing the size of the alkoxy group.
- Otera, Junzo,Fujita, Yukihiro,Fukuzumi, Shunichi
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p. 9409 - 9418
(2007/10/03)
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- Stereochemistry of the Michael Addition of N,N-Disubstituted Amide and Thioamide Enolates to α,β-Unsaturated Ketones
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A systematic study of the regio- and diastereoselectivity of the kinetic Michael addition of amide and thioamide enolates to a series of α,β-unsaturated ketones has been carried out.Factors that influence the diastereo- and regiochemical outcome of the reaction include the substitution pattern of the enone and enolate, the enolate counterion, and the solvent.Numerous examples of high selectivity have been discovered.In a number of examples, either the syn or the anti addition products can be obtained by varying the nature of the solvent, donor atom, and/or counterion.These results have correlated in terms of a coherent transition-state model.
- Oare, David A.,Henderson, Mark A.,Sanner, Mark A.,Heathcock, Clayton H.
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p. 132 - 157
(2007/10/02)
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- α, β-Unsaturated N-Acylureas as Useful Intermediates for the Synthesis of Indanones, Chromanones and Coumarins
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α,β-Unsaturated N-acylureas, viz-N-formamido-2-butenamide (I), N-formamido-3-methyl-2-butenamide (II) and N-formamido-3-phenyl-2-propenamide (III) react with aryl alkyl ethers in the presence of PPA to afford the corresponding crotonophenones and chalcones (IV) at lower temperature and 1-indanones (V) at a higher temperature.Reactions of I and II with phenols in the presence of PPA afford the 4-chromanones (VI), while III gives 3,4-dihydro-4-phenylcoumarins (VII) in excellent yields.
- Ramana, M. M. V.,Kudav, N. A.
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p. 339 - 341
(2007/10/02)
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