- 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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- 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 0047-0050
(2020/08/27)
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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 0100-0103
(2017/08/25)
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- Synthesis method of hydroxyketone compounds
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The invention relates to a synthesis method of hydroxyketone compounds represented by the following formula (II). The method comprises the steps: at room temperature, successively adding a compound represented by the following formula (I), a catalyst and
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Paragraph 0044; 0045; 0046, 0047; 0048
(2016/10/08)
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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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- Iodine promoted α-hydroxylation of ketones
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A novel method for α-hydroxylation of ketones using substoichiometric amount of iodine under metal-free conditions is described. This method has been successfully employed in synthesizing a variety of heterocyclic compounds, which are useful precursors. α-Hydroxylation of diketones and triketones are illustrated. This strategy provides a novel, efficient, mild and inexpensive method for α-hydroxylation of aryl ketones using a sub-stoichiometric amount of molecular iodine.
- Siddaraju, Yogesh,Prabhu, Kandikere Ramaiah
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supporting information
p. 6749 - 6753
(2015/06/25)
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- 3,8-DIAZA-BICYCLO[4.2.0]OCT-3-YL AMIDES
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The present invention relates to 3,8-diaza-bicyclo[4.2.0]oct-3-yl amide derivatives of formula (I), wherein the relative configuration of the diazabicyclooctane moiety is cis; and wherein Ar1, and Ar2 are as described in the description, to their preparation, to pharmaceutically acceptable salts thereof, and to their use as pharmaceuticals, to pharmaceutical compositions containing one or more compounds of formula (I), and especially to their use as orexin receptor antagonists.
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Page/Page column 72
(2012/07/13)
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- 3,8-DIAZA-BICYCLO[4.2.0]OCT-8-YL AMIDES
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The present invention relates to 3,8-diaza-bicyclo[4.2.0]oct-8-yl amide derivatives of formula (I) Formula (I) wherein the relative configuration of the diazabicyclooctane moiety is cis; and wherein Ar1, and Ar 2 are as described in the description, to their preparation, to pharmaceutically acceptable salts thereof, and to their use as pharmaceuticals, to pharmaceutical compositions containing one or more compounds of formula (I), and especially to their use as orexin receptor antagonists.
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Page/Page column 63
(2012/07/13)
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- Hyphenating the curtius rearrangement with morita-baylis-hillman adducts: Synthesis of biologically active acyloins and vicinal aminoalcohols
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Using Morita-Baylis-Hillman adducts as substrates, the Curtius rearrangement was performed in a sequence that allowed the synthesis of several hydroxy-ketones (acyloins) with great structural diversity and in good overall yields. These acyloins in turn were easily transformed into 1,2-anti aminoalcohols through a highly diastereoselective reductive amination step. The synthetic utility of these approaches was exemplified by performing the syntheses of (±)-bupropion, a drug used to treat the abstinence syndrome of smoker and (±)-spisulosine, a potent anti-tumoral compound originally isolated form a marine source.
- Amarante, Giovanni W.,Cavallaro, Mayra,Coelho, Fernando
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p. 1568 - 1584
(2011/11/06)
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- Acyloins from Morita-Baylis-Hillman adducts: an alternative approach to the racemic total synthesis of bupropion
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In this Letter, we describe an easy and straightforward strategy for the preparation of acyloins (α-hydroxyketones) from Morita-Baylis-Hillman adducts, based on a Curtius rearrangement. Different acyloins were obtained with good overall yield (>40% for three steps). To exemplify the synthetic usefulness of this strategy, total synthesis of (±)-bupropion, a dopamine, and nor-epinefrine reuptake inhibitor has been accomplished in eight steps with an overall yield of 25%.
- Amarante, Giovanni W.,Rezende, Patrícia,Cavallaro, Mayra,Coelho, Fernando
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p. 3744 - 3748
(2008/09/21)
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- Simple chemoenzymatic access to enantiopure pharmacologically interesting (R)-2-hydroxypropiophenones
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A chemoenzymatic synthesis of pharmacological interesting (R)-2-hydroxypropiophenones starting from propiophenone derivatives is described. Manganese(III) acetate-mediated acetoxylation followed by fungus-mediated hydrolysis of propiophenone derivatives affords (R)-2-hydroxypropiophenones in high enantiomeric excess.
- Demir, Ayhan S.,Hamamci, Haluk,Sesenoglu, Ozge,Aydogan, Feray,Capanoglu, Doga,Neslihanoglu, Rahsan
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p. 1953 - 1956
(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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