- Convenient synthesis of 4,5-unsubstituted 3-aroylisoxazoles from methyl aryl ketones and (vinylsulfonyl)benzene in water
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A convenient synthesis of 3-aroylisoxazoles from methyl ketones and (vinylsulfonyl)benzene in 2%TPGS-750-M/H2O has been developed. This reaction proceeds via tandem tert-butyl nitrite-promoted Csp3-H functionalization of methyl ketones, 1,3-dipolar cycloaddition and base-catalyzed aromatization, providing the corresponding products in moderate to good yields.
- Wang, Liang,Tao, Yu,Zhang, Nana,Li, Shubai
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- Enolate-Based Regioselective Anti-Beckmann C-C Bond Cleavage of Ketones
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The Baeyer-Villiger or Beckmann rearrangements are established methods for the cleavage of ketone derivatives under acidic conditions, proceeding for unsymmetrical precursors selectively at the more substituted site. However, the fragmentation regioselectivity cannot be switched and fragmentation at the less-substituted terminus is so far not possible. We report here that the reaction of ketone enolates with commercial alkyl nitrites provides a direct and regioselective way of fragmenting ketones into esters and oximes or ω-hydroxyimino esters, respectively. A comprehensive study of the scope of this reaction with respect to ketone classes and alkyl nitrites is presented. Control over the site of cleavage is gained through regioselective enolate formation by various bases. Oxidation of kinetic enolates of unsymmetrical ketones leads to the otherwise unavailable "anti-Beckmann"cleavage at the less-substituted side chain, while cleavage of thermodynamic enolates of the same ketones represents an alternative to the Baeyer-Villiger oxidation or the Beckmann rearrangement under basic conditions. The method is suited for the transformation of natural products and enables access to orthogonally reactive dicarbonyl compounds.
- Jahn, Ullrich,Ma?ek, Tomá?
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p. 11608 - 11632
(2021/09/02)
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- Dual photoredox/palladium-catalyzed C-H acylation of 2-arylpyridines with oxime esters
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An unprecedented dual photoredox/palladium-catalyzed iminyl-radical-mediated C-C bond cleavage and directed ortho C-H acylation of 2-arylpyridines by using oxime esters is described. Oxime esters can serve as efficient acyl sources through formation of the corresponding acyl radicals by photoredox-catalyzed iminyl-radical-mediated C-C bond cleavage. This redox-neutral protocol features excellent regioselectivity, a broad substrate scope, and good functional-group tolerance with respect to both components, giving a broad range of aryl ketones with generally good yields.
- He, Bin-Qing,Gao, Yuan,Wang, Peng-Zi,Wu, Hong,Zhou, Hong-Bin,Liu, Xiao-Peng,Chen, Jia-Rong
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supporting information
p. 373 - 377
(2020/09/11)
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- Visible-Light Photoredox-Catalyzed Dicarbofunctionalization of Styrenes with Oxime Esters and CO2: Multicomponent Reactions toward Cyanocarboxylic Acids and γ-Keto Acids
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A photoredox-catalyzed dicarbofunctionalization of styrenes with oxime esters and CO2 has been achieved. Notably, a series of four-, five-, or six-membered cyclic ketone oximes worked well to furnish a wide range of ε-, ζ-, and η-cyanocarboxylic acids in good yields. Furthermore, a series of γ-keto acids also could be obtained by employing acyclic ketone oxime esters as the carbonyl radical precursor. It provides convergent access to diverse biologically important cyanocarboxylic and γ-keto acids.
- Bai, Junxue,Li, Miao,Zhou, Cong,Sha, Yu,Cheng, Jiang,Sun, Jianwei,Sun, Song
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supporting information
p. 9654 - 9658
(2021/12/14)
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- NOVEL PROCESS FOR THE PREPARATION OF R-PHENYLACETYLCARBINOL AND β-AMINOALCOHOLS
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Disclosed herein is a process for the manufacture of (R)-phenylacetylcarbinol ((R)-PAC), (1R,2S). Ephedrine and its salts, (1R,2S)-norephedrine and its salts and 1-(Phenyl/Substituted phenyl)-2-(amino/alkylamino/dialklyamino) propan-1-ol and its salts, by enzymatic reduction of α-isonitrosopropiophenone (INP) and substituted α-isonitrosopropiophenone (substituted INP). The β-amino alcohols, produced by the process of present invention gives their corresponding diastereomers on Walden inversion. The present preparation process of (R)-PAC with (R)-PAC oxime as an intermediate has the advantage, that propiophenone as a key raw material which is easily available and has a low-price, operationally simple with high yield and a single process leading to the synthesis of several 1,2-aminoalcohol/ β- aminoalcohols active pharmaceutical ingredients. The design approach of the process is to reduce environmental impact of the product by comparing to the present manufacturing process.
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Page/Page column 8; 9
(2020/07/14)
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- Site-selective conversion of azido groups at carbonyl α-positions into oxime groups leading triazide to a triple click conjugation scaffold
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This paper reports the selective conversion of alkyl azido groups at the carbonyl α-position into oximes through β-elimination of dinitrogen, followed by transoximation. With this method and diazo conversion, a triazido molecule was transformed into a triple click conjugation scaffold allowing one-pot four-component coupling.
- Yokoi, Taiki,Ueda, Tomomi,Tanimoto, Hiroki,Morimoto, Tsumoru,Kakiuchi, Kiyomi
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supporting information
p. 1891 - 1894
(2019/05/02)
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- Synthesis of N-Aryl Oxindole Nitrones through a Metal-Free Selective N-Arylation Process
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An efficient selective N-arylation of 3-(hydroxyimino)indolin-2-ones with diaryliodonium salts to prepare (Z)-N-aryl oxindole nitrones has been achieved under simple base-mediated conditions. The reaction tolerated a variety of diaryliodonium salts with diverse and sensitive functional groups. Studies on the oxime structures revealed that the pyrroline ring and carbonyl group in 3-(hydroxyimino)indolin-2-ones played important roles in the selective N-arylation process. The N-aryl oxindole nitrones could be prepared rapidly and easily at the gram scale.
- Wu, Si-Yi,Ma, Xiao-Pan,Liang, Cui,Mo, Dong-Liang
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p. 3232 - 3238
(2017/03/23)
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- Method for synthesizing novel photoinitiator 1-phenyl-1,2-propanedione
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The invention relates to a new process for synthesizing a novel photoinitiator 1-phenyl-1,2-propanedione. The process comprises the steps of subjecting propiophenone, which serves as a starting raw material, to a reaction with ethyl nitrite in the presence of hydrogen chloride so as to obtain 1-phenyl-1,2-propanedion-2-oxime, and further carrying out hydrolysis in the presence of a mixed solution of formaldehyde, hydrochloric acid and ethanol, thereby obtaining 1-phenyl-1,2-propanedione. According to the process, the influence on production of 1-phenyl-1,2-propanedion-2-oxime caused by hydrogen chloride in the reaction and the influence on production of 1-phenyl-1,2-propanedione caused by formaldehyde and ethanol during acidic hydrolysis are surveyed, and optimized conditions for producing 1-phenyl-1,2-propanedione are determined.
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Paragraph 0023-0024; 0027
(2017/07/20)
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- Synthesis method of 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime serving as photoinitiator
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The invention relates to a novel synthesis process of 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime serving as a photoinitiator. The synthesis process comprises the following steps: performing reaction on propiophenone serving as a start raw material and mitrous ether under the action of hydrogen chloride, thus obtaining 1-phenyl-1,2-propanedione-2-oxime; and further performing reaction on the 1-phenyl-1,2-propanedione-2-oxime and ethyl chloroformate under the action of anhydrous potassium carbonate or triethylamine, thus obtaining the 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime (PDO). According to the synthesis process, the influence of the hydrogen chloride on the production of the 1-phenyl-1,2-propanedione-2-oxime and the influence of the anhydrous potassium carbonate or triethylamine serving as an acid-binding agent on the production of the 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime during the reaction are inspected, optimal conditions for producing the 1-phenyl-1,2-propanedione-2-oxime and the 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime is determined, and a novel process which is easy to operate and environmentally-friendly is provided.
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Paragraph 0019; 0022;0023
(2017/07/21)
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- Ruthenium-catalyzed hydrovinylation of N-acetylenamines leading to amines with a quaternary carbon center
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A catalytic hydrovinylation of N-acetylenamines with ethylene is reported. This new hydrovinylation reaction is catalyzed by a ruthenium hydride complex, RuHCl(CO)(PCy3)2, providing a series of N-acetylamines with a quaternary carbon center with up to 99% yield.
- Wang, Qiu-Shi,Xie, Jian-Hua,Li, Wei,Zhu, Shou-Fei,Wang, Li-Xin,Zhou, Qi-Lin
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supporting information; scheme or table
p. 3388 - 3391
(2011/08/21)
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- A rapid synthesis of quinoxalines starting from ketones
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A fast and general synthesis of quinoxalines, performed in two stages or as a one-pot reaction, starting from ketones via their α-hydroxylimino ketone derivatives, and condensation of the latter with 1,2-diaminobenzene under microwave irradiation, is described.
- Padmavathy,Nagendrappa, Gopalpur,Geetha
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experimental part
p. 544 - 547
(2011/03/18)
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- Preparation and structure of optically active imidazolium tetrafluoroborates : In search of new chiral ionic liquids
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Enantiomerically pure (R)-l-(l-phenylethyl)imidazoles 4a,b can be prepared conveniently from α-(hydroxyimino)ketones 1, (R)-l-phenylethylamine and formaldehyde, followed by deoxygenation with Raney-Ni. Similarly, the reaction with (R,R)-trans-cyc-lohexane-l,2-diamine yields enantiomerically pure (R, R)-trans-1,1'-cyclohex-ane-l,2-diyl)imidazoles 4c,d. Alkylation of these imidazole derivatives with alkylbromides leads to the corresponding 3-alkylimidazolium bromides 6 and 8, respectively, which on treatment with sodium tetrafluoroborate are transformed into the corresponding tetrafluoroborates 7 and 9. Whereas some of the imidazolium salts 7 show properties of chiral ionic liquids, the bis-imidazolium tetrafluoroborates 9 are high-melting crystalline materials.
- Mloston,Mucha,Tarka,Urbaniak,Linden,Heimgartner
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experimental part
p. 1105 - 1114
(2010/03/01)
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- Reaction of Z isomers of alkylaromatic 1,2-hydroxylamino oximes with 1,2-diketones
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The reactions of Z isomers of alkylaromatic 1,2-hydroxylamino oximes containing the hydroxylamino group at the primary or secondary carbon atom with diacetyl afford 6-acetyl-5,6-dihydro-4H-1,2,5-oxadiazines. The reactions of these compounds with alkylaromatic 1,2-diketones produce N-substituted α-aroylnitrones or 6-aroyl-5,6-dihydro-4H-1,2,5-oxadiazines or, alternatively, their tautomeric mixtures.
- Amitina,Grigor'ev,Tikhonov
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p. 1046 - 1051
(2008/02/01)
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- Imidazole based kinase inhibitors
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The present invention provides compounds having Formula I and their use for the treatment of cancer.
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Page/Page column 12
(2008/06/13)
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- Synthesis of 2,4,5-Trisubstituted Oxazoles
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2,4,5-Trisubstituted oxazoles were synthesized in good yields starting from α-methylene ketones by nitrosation, condensation with aldehydes and reduction with zinc in acetic acid at 40 deg C. (5-Methyl-2-phenyloxazol-4-yl)ethanol was prepared by reduction of ethyl (5-methyl-2-phenyloxazol-4-yl)acetate with LiAlH4.
- Cai, Xiao-hua,Yang, Hai-jun,Zhang, Guo-lin
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p. 1569 - 1571
(2007/10/03)
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- Chemistry of indoles carrying a basic function. Part VII. A new aspect of Stobbe reaction
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While performing Stobbe reactions of a succinic diester derivative (1) different routes were found leading to different indole derivatives (2-5) depending on the reaction conditions applied, thus widening the scope and limitation of this useful procedure. Simpler pyrrolidine (13) and piperidine derivatives (14, 15) were also achieved through application of the intramolecular Stobbe reaction.
- Moldvai, István,Temesvári-Major, Eszter,Incze, Mária,Platthy, Tünde,Gács-Baitz, Eszter,Szántay, Csaba
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p. 309 - 319
(2007/10/03)
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- A remarkably simple α-oximation of ketones to 1,2-dione monooximes using the chlorotrimethylsilane-isoamyl nitrite combination
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Ketones undergo α-oximation by NOCl formed in situ from Me3SiCl and isoamyl nitrite, either in solution or under solvent-free conditions, to produce 1,2-dione monooximes in excellent yields. The oximation is regiospecific in appropriate cases.
- Mohammed, Abdulkarim H.A.,Nagendrappa, Gopalpur
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p. 2753 - 2755
(2007/10/03)
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- A new and general method for the synthesis of quinoxalines
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A new and general synthetic method for the preparation of 2,3-disubstituted quinoxalines is described. Treatment of ?-phenylenediamine with α-ketoaldoximes in ethanol affords 2,3-disubstituted quinoxalines in one-step reaction.
- Tajbakhsh,Bakooie,Ghassemzadeh,Beheshtiha,Heravi
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p. 1232 - 1233
(2007/10/03)
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- ORGANIC SYNTHESIS USING ORGANOSULFUR-NITRITES AND -NITRATES
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Thionitrites or thionitrates have been considered to be unstable.However, bulky groups' thio-NOn such as t-butylthio-nitrites and -nitrates have been readily synthesized and found to be stable enough for the use of the useful organic syntheses as an excellent nitrosation and diazotization reagents under mild conditions.Direct conversion of amines to the corresponding halides in the presence of copper halides (II), fluorination of heterocyclic amines in the presence of sodium tetrafluoroborate, α- oximation of methylene groups in ketones, facile cleavage of C=N bond to ketones, and desulfurization of thioacetals and thioketals, and other useful organic syntheses are described.
- Kim, Yong Hae
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p. 249 - 260
(2007/10/02)
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- Reactions of Ethyl phosphites with β-Nitrostyrenes. The Role of Nitrosoalkenes as Intermediates
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3-Phenyl-2-substituted-indoles are formed in high yields in the reaction of Ph2C=C(R)NO2 (R = H, Me, Ph) with (EtO)3P at 150 deg C while reaction with (EtO)2PO(1-)/(Et2O)P(O)H at room temperature forms the aziridines 1 with R = H, Me, Ph. 2,2-Diphenyl-3-substituted-2H-azirines formed by deoxygenation of the Michael-type aducts are postulated as intermediates.Reactions of PhCH=C(R)NO2 (R = H, Me, Ph) with (EtO)3P at 150 deg C or (EtO)2PO(1-)/(EtO)2P(O)H at room temperature give products resulting from the addition of the phosphorus nucleophile at the benzylidene carbonatom.Evidence for the formation of cyclic structures with pentacoordinated phosphorus atoms is presented for the reaction of Ph2C=C(Me)NO2 with (EtO)2PO(1-)/(EtO)2P(O)H and for PhCH=C(R)NO2 (R = H, Me, Ph) with (EtO)3P.The Michael-type adducts PhCHCH(R)NO2 (R = Me, Ph) undergo reaction upon treatment with aqueous base at 80-100 deg C followed by acidification to yield the 3-(diethoxyphosphinyl)-2-R-N-hydroxyindoles. 4-(Diethoxyphosphinyl)-3-R-4H-1,2-benzoxazines (13, R = Me, Ph) are formed by reaction with 85percent H2SO4 of the adducts of PhCH=C(R)NO2 with (EtO)2PO(1-) (R = Me) or (EtO)3P (R = Ph).
- Russell, Glen A.,Yao, Ching-Fa
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p. 6508 - 6513
(2007/10/02)
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- A Novel and Efficient Method for the Preparation of α-Hydroxyimino Carbonyl Compounds from α,β-Unsaturated Carbonyl Compounds with Butyl Nitrite and Phenylsilane Catalyzed by a Cobalt(II) Complex
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Various α,β-unsaturated carbonyl compounds, such as α,β-unsaturated esters, α,β-unsaturated ketones, α,β-unsaturated nitriles, and α,β-unsaturated amides, were directly converted to the corresponding α-hydroxyimino carbonyl compounds in high yields on treatment with butyl nitrite and phenylsilane in the presence of a catalytic amount of N,N'-bis(2-ethoxycarbonyl-3-oxobutylidene)ethylenediaminatocobalt(II) complex under mild conditions.
- Kato, Koji,Mukaiyama, Teruaki
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p. 2948 - 2953
(2007/10/02)
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- TeCl4-Mediated Reaction of β-Keto Nitroalkanes with Activated Olefins. Formation of 3-Acyl-2-isoxazolines
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Treatment of β-keto nitroalkanes with tellurium tetrachloride followed by triethylamine in the presence of activated olefins leads to 3-acyl-2-isoxazolines in good to modes yields.
- Suzuki, Hitomi,Shimizu, Hiroshi,Inamasu, Tokuo,Tani, Hiroyuki,Tamura, Rui
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p. 559 - 562
(2007/10/02)
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- FACILE DIRECT α-OXIMATION OF KETONES USING t-BUTYL THIONITRATE
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Various ketones containing methylene groups at α-position were found to react with t-butyl thionitrate at 0 deg C in tetrahydrofuran to give the corresponding α-oximino-ketones in excellent yield.
- Kim, Yong Hae,Park, Young Jun,Kim, Kweon
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p. 2833 - 2836
(2007/10/02)
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