- An efficient method for the synthesis of α-hydroxyalkyl aryl ketones
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Exposure of alkyl aryl ketones to Oxone/trifluoroacetic anhydride in the presence of a catalytic amount of iodobenzene affords α-hydroxyalkyl aryl ketones in good yield. This method provides an effective and economical entry for the installation of α-hydroxy moieties into ketones and should find wide application in the construction of the α-hydroxy ketone subunit in natural product synthesis.
- Chen, Chengqun,Feng, Xinghua,Zhang, Guozhen,Zhao, Qin,Huang, Guosheng
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- Chiral Primary Amine Catalyzed Enantioselective Tandem Reactions Based on Heyns Rearrangement: Synthesis of α-Tertiary Amino Ketones
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Herein, we disclose a new catalytic asymmetric tandem reaction based on the Heyns rearrangement for the synthesis of chiral α-amino ketones with readily available substrates. The rearrangement is different from the Heyns rearrangement in that the α-amino ketones were obtained without the shift of the carbonyl group. The key to success is using chiral primary amine as a catalyst by mimicking glucosamine-6-phosphate synthase in catalyzing the efficient Heyns rearrangement in organisms.
- Chen, Yue,Cui, Xin,Li, Guang-Xun,Nie, Xiao-Kang,Tang, Zhuo,Zhang, Shi-Qi
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p. 2069 - 2074
(2022/03/31)
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- Organocatalytic Synthesis of Substituted Vinylene Carbonates
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The organocatalytic synthesis of substituted vinylene carbonates from benzoins and acyloins was studied using diphenyl carbonate as a carbonyl source. A range of N-Heterocyclic Carbene (NHC) precursors were screened and it was found that imidazolium salts were the most active for this transformation. The reaction occurs at 90 °C under solvent-free conditions. A wide range of substituted vinylene carbonates (symmetrical and unsymmetrical, aromatic or aliphatic), including some derived from natural products, were prepared with 20–99% isolated yields (24 examples). The reaction was also developed using thermomorphic polyethylene-supported organocatalysts as recoverable and recyclable species. The use of such species facilitates the workup and allows the synthesis of vinylene carbonates on the preparative scale (>30 g after 5 runs). (Figure presented.).
- Onida, Killian,Haddleton, Alice J.,Norsic, Sébastien,Boisson, Christophe,D'Agosto, Franck,Duguet, Nicolas
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supporting information
p. 5129 - 5137
(2021/09/18)
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- Green preparation method α - hydroxyketone
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The invention relates to a green preparation method of alpha-hydroxyketone. The method comprises the following steps: adding ketone, iodine, 1,4-diazabicyclo[2.2.2]octane and methanol into a glass reaction bottle in sequence; then stirring and reacting for 14 to 30h at room temperature in an air atmosphere under the irradiation of a 23W compact type fluorescent lamp, so as to obtain a reaction mixture; carrying out silica gel column chromatographic separation to obtain the pure alpha-hydroxyketone. The green preparation method provided by the invention has the characteristics of greenness, high efficiency, simplicity in operation, moderate conditions, wide applicability and easiness for industrialization.
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Paragraph 0023-0026
(2020/08/27)
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- Solvent-Free Synthesis of α-Amino Ketones from α-Hydroxyl Ketones via A Novel Tandem Reaction Sequence Based on Heyns Rearrangement
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Heyns rearrangement have been famous for carbohydrate chemists for several decades. However, this reaction was underrated as a useful method for synthetic chemists due to preparative shortcomings. Herein we developed an efficient method for the synthesis of pharmaceutically important α-amino ketones from readily available α-hydroxy ketones and secondary amines through a tandem reaction sequence based on Heyns rearrangement. The reaction smoothly proceeded by using catalytic PTSA as catalyst without solvent. Primary and secondary α-hydroxy ketones were readily used and regioselectively afforded the correspondingly α-amino ketones with moderate yield.
- Li, Ling-Yu,Zeng, Qing-Le,Li, Guang-Xun,Tang, Zhuo
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supporting information
p. 694 - 699
(2019/03/26)
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- Halogen-bonded iodonium ion catalysis: A route to α-hydroxy ketones: Via domino oxidations of secondary alcohols and aliphatic C-H bonds with high selectivity and control
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A domino synthesis of α-hydroxy ketones has been developed from benzylic secondary alcohols employing catalytic iodonium ions stabilized by DMSO. The reaction proceeds through an unprecedented sequential oxidation of alcohols to ketone and its α-hydroxylation in a controlled manner. The spectroscopic evidence establishes the possibility of formation of a stable halogen-bonded adduct between DMSO and iodonium ions.
- Guha, Somraj,Kazi, Imran,Mukherjee, Pranamita,Sekar, Govindasamy
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p. 10942 - 10945
(2017/10/13)
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- Α - hydroxy ketone compound low priced high-efficient synthetic method
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The invention discloses a cheap and efficient synthesis method of an alpha-hydroxyketone compound. The synthesis method is characterized in that a carbonyl compound undergoes an oxidation hydroxylation reaction at 10-120DEG C under normal pressure with iodine simple substance, N-bromosuccimide, copper bromide, bromine simple substance, hydrogen bromide, N-iodosuccimide or hydrogen iodide as a catalyst, sulfoxide as an oxidant, water or sulfoxide as a hydroxy source and sulfoxide, ethyl acetate, N,N-dimethyl formamide, acetonitrile, toluene, 1,4-dioxane, 1,2-dichloroethane, tetrahydrofuran or H2O as a solvent, and converts into the alpha-hydroxyketone compound in a high selectivity manner. Compared with traditional synthesis methods, the method disclosed in the invention has the advantages of simple operation, high yield, simple conditions, easy purification, small waste discharge amount, simple reaction apparatus, and easy industrial production. The method has wide applicability and can be used for synthesizing various alpha-hydroxyketone compounds.
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Paragraph 0076-0079
(2017/08/25)
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- N,N-Dimethylformamide (DMF) as a Source of Oxygen to Access α-Hydroxy Arones via the α-Hydroxylation of Arones
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An unprecedented α-hydroxylation strategy was developed for the synthesis of α-hydroxy arones using N,N-dimethylformamide (DMF) as an oxygen source. Control experiments demonstrated that the oxygen atom of the hydroxy group in the α-hydroxy arones produced in this reaction was derived from DMF. This new reaction therefore not only provides an alternative strategy for the α-hydroxylation of arones but also highlights the possibility of using the inexpensive common solvent DMF as a source of oxygen in organic synthesis.
- Liu, Weibing,Chen, Cui,Zhou, Peng
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p. 2219 - 2222
(2017/02/26)
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- I2- or NBS-catalyzed highly efficient α-hydroxylation of ketones with dimethyl sulfoxide
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An efficient method for the direct preparation of high synthetic valuable α-hydroxycarbonyls is described. The simple and readily available I2 or NBS was used as catalyst. DMSO acts as the oxidant, oxygen source, and solvent. A diverse range of tertiary Csp3-H bonds as well as more challenging secondary Csp3-H bonds could be hydroxylated in this transformation. The reaction is mild, less toxic and easy to perform.
- Liang, Yu-Feng,Wu, Kai,Song, Song,Li, Xinyao,Huang, Xiaoqiang,Jiao, Ning
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supporting information
p. 876 - 879
(2015/04/14)
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- Switching regioselectivity in crossed acyloin condensations between aromatic aldehydes and acetaldehyde by altering n -heterocyclic carbene catalysts
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An unprecedented high level of regioselectivities (up to 96%) in the intermolecular crossed acyloin condensations of various aromatic aldehydes with acetaldehyde was realized by an appropriate choice of N-heterocyclic carbene catalysts.(Figure Presented)
- Jin, Ming Yu,Kim, Sun Min,Han, Hogyu,Ryu, Do Hyun,Yang, Jung Woon
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supporting information; experimental part
p. 880 - 883
(2011/05/02)
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- Synthesis of α-acetoxy and formyloxy ketones by thallium(III) promoted α-oxidation
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Treatment of ketones with thallium(III) triflate in amide solvents at 60°C for 30 min followed by addition of small amounts of H2O cleanly provided the corresponding α-acyloxy ketones.
- Lee,Jin,Choi
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p. 956 - 957
(2007/10/03)
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- Enantioselective synthesis of (S)-2-hydroxypropanone derivatives by benzoylformate decarboxylase catalyzed C-C bond formation
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Chiral 2-hydroxypropanone derivatives 5a-v, 8a-d, and 10a, b were formed by benzoylformate decarboxylase (BFD) catalyzed C-C bond formation. A donor aldehyde and acetaldehyde as an acceptor were carboligated in aqueous buffer solution with remarkable ease in high chemical yield and good to high optical purity. The substrate range of this thiamin diphosphate dependent enzyme was examined to employ this benzoin condensation type reaction in stereoselective synthesis. The observed dependence of the enantiomeric excess on the substitution pattern could be exploited to design substrates resulting in high selectivity. Best substrates with regard to optical purity were meta- substituted benzaldehyde derivatives. To enable a general and convenient applicability of the BFD-catalyzed C-C bond formation, analytical batch experiments were scaled up to give (S)-2-hydroxy ketones in good to high yields on a preparative scale. Further, the solubility of some of the organic substrates in aqueous solution was increased by the use of cyclodextrin or buffer/DMSO mixtures.
- Duennwald, Thomas,Demir, Ayhan S.,Siegert, Petra,Pohl, Martina,Mueller, Michael
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p. 2161 - 2170
(2007/10/03)
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- A new procedure for α-hydroxylation of ketones using thallium(III) p-nitrobenzenesulfonate (TNS)
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An efficient method for conversion of ketones to α-hydroxyketones by treatment of thallium(III) p-nitrobenzenesulfonate with ketones and subsequent hydrolysis using DMSO/H2O in one pot system is described.
- Lee, Jong Chan,Park, Chunkyung,Choi, Youngsup
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p. 4079 - 4084
(2007/10/03)
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