473-84-7Relevant academic research and scientific papers
Novel hypervalent iodine catalyzed synthesis of α-sulfonoxy ketones: Biological activity and molecular docking studies
Atmaca, Ufuk,Alp, Cemalettin,Akincioglu, Hulya,Karaman, Halide Sedef,Gül?in, ?lhami,?elik, Murat
, (2021)
The novel di((camphorsulfonyl)oxy)iodo]benzene (DCIB) was synthesized from [Bis(trifluoroacetoxy)iodo]benzene in the mild conditions. The α-sulfonoxylation of various ketones with novel hypervalent iodine was reported in excellent yield. α-Hydroxyketones
Enantioselective Cascade Biocatalysis for Deracemization of Racemic β-Amino Alcohols to Enantiopure (S)-β-Amino Alcohols by Employing Cyclohexylamine Oxidase and ω-Transaminase
Zhang, Jian-Dong,Chang, Ya-Wen,Dong, Rui,Yang, Xiao-Xiao,Gao, Li-Li,Li, Jing,Huang, Shuang-Ping,Guo, Xing-Mei,Zhang, Chao-Feng,Chang, Hong-Hong
, p. 124 - 128 (2020/09/21)
Optically active β-amino alcohols are very useful chiral intermediates frequently used in the preparation of pharmaceutically active substances. Here, a novel cyclohexylamine oxidase (ArCHAO) was identified from the genome sequence of Arthrobacter sp. TYUT010-15 with the R-stereoselective deamination activity of β-amino alcohol. ArCHAO was cloned and successfully expressed in E. coli BL21, purified and characterized. Substrate-specific analysis revealed that ArCHAO has high activity (4.15 to 6.34 U mg?1 protein) and excellent enantioselectivity toward the tested β-amino alcohols. By using purified ArCHAO, a wide range of racemic β-amino alcohols were resolved, (S)-β-amino alcohols were obtained in >99 % ee. Deracemization of racemic β-amino alcohols was conducted by ArCHAO-catalyzed enantioselective deamination and transaminase-catalyzed enantioselective amination to afford (S)-β-amino alcohols in excellent conversion (78–94 %) and enantiomeric excess (>99 %). Preparative-scale deracemization was carried out with 50 mM (6.859 g L?1) racemic 2-amino-2-phenylethanol, (S)-2-amino-2-phenylethanol was obtained in 75 % isolated yield and >99 % ee.
Site-Selective and Product Chemoselective Aliphatic C-H Bond Hydroxylation of Polyhydroxylated Substrates
Bietti, Massimo,Borrell, Margarida,Costas, Miquel,Gil-Caballero, Sergio
, p. 4702 - 4709 (2020/05/19)
Site-selective and product chemoselective aliphatic C-H bond oxidation of 1,2-diols and of polyhydroxylated substrates using iron and manganese catalysts and hydrogen peroxide as terminal oxidant is described. The reaction capitalizes on the use of fluorinated alcohol solvents such as 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), which exert a strong polarity reversal in the hydroxyl moieties of 1,2-diols via hydrogen bonding, in turn translating into a strong deactivation of proximal C-H bonds against a HAT initiated oxidation by the putative high-valent and electrophilic metal-oxo species. As a result, site-selective and product chemoselective oxidation of complex polyfunctional molecules such as steroids, sugars, and pharmaceuticals is described, where exclusive or predominant C-H bond hydroxylation at a remote and nonactivated site takes place. The current report discloses HAT initiated hydroxylations in fluorinated alcohol solvents as methods displaying orthogonal chemoselectivity to contemporary alcohol oxidations providing a useful tool for synthetic planning in densely functionalized molecules.
One-Pot Enzymatic Synthesis of Cyclic Vicinal Diols from Aliphatic Dialdehydes via Intramolecular C?C Bond Formation and Carbonyl Reduction Using Pyruvate Decarboxylases and Alcohol Dehydrogenases
Zhang, Yan,Yao, Peiyuan,Cui, Yunfeng,Wu, Qiaqing,Zhu, Dunming
, p. 4191 - 4196 (2018/09/25)
An enzymatic cascade reaction was developed for one-pot enantioselective conversion of aliphatic dialdehydes to chiral vicinal diols using pyruvate decarboxylases (PDCs) and alcohol dehydrogenases (ADHs). The PDCs showed promiscuity in catalysing the cyclization of aliphatic dialdehydes through intramolecular stereoselective carbon-carbon bond formation. Consequently, 1,2-cyclopentanediols in three different stereoisomeric forms and 1,2-cyclohexanediols in two different stereoisomeric forms could be prepared with high conversion and stereoisomeric ratio from the respective initial substrates, glutaraldehyde and adipaldehyde. These cascade reactions represent a promising approach to the biocatalytic synthesis of important chiral vicinal diols. (Figure presented.).
Ligustrazine-fused cyclic compound and medicine composition thereof, as well as application in medicine thereof
-
Paragraph 0038; 0039; 0040; 0042, (2017/07/21)
The invention discloses a ligustrazine-fused cyclic compound and a medicine composition thereof and application in a medicine. The ligustrazine-fused cyclic compound has the following structural general formula I: as shown in the specification. The medicine composition is a medicinal active component for the ligustrazine-fused cyclic compound and a pharmaceutically acceptable carrier, an excipient, a diluent, an adjuvant, a medium or a combination thereof; the ligustrazine-fused cyclic compound and the medicine composition can be used for preventing or treating cardiovascular and cerebrovascular diseases, digestive system diseases, respiratory diseases, the alzheimer's disease, kidney diseases and complications of the above-mentioned diseases due to thrombus and excessive free radicals. The ligustrazine-fused cyclic compound disclosed by the invention has an extremely good inhibition effect on in vitro ADP (adenosine diphosphate)-induced platelet aggregation; meanwhile, compared with the pharmacokinetic property of ligustrazine serving as a female parent, the pharmacokinetic property of the ligustrazine-fused cyclic compound in the body of a rat is obviously improved.
Chiral-Substituted Poly-N-vinylpyrrolidinones and Bimetallic Nanoclusters in Catalytic Asymmetric Oxidation Reactions
Hao, Bo,Gunaratna, Medha J.,Zhang, Man,Weerasekara, Sahani,Seiwald, Sarah N.,Nguyen, Vu T.,Meier, Alex,Hua, Duy H.
supporting information, p. 16839 - 16848 (2017/01/10)
A new class of poly-N-vinylpyrrolidinones containing an asymmetric center at C5 of the pyrrolidinone ring were synthesized from l-amino acids. The polymers, particularly 17, were used to stabilize nanoclusters such as Pd/Au for the catalytic asymmetric oxidations of 1,3- and 1,2-cycloalkanediols and alkenes, and Cu/Au was used for C-H oxidation of cycloalkanes. It was found that the bulkier the C5 substituent in the pyrrolidinone ring, the greater the optical yields produced. Both oxidative kinetic resolution of (±)-1,3- and 1,2-trans-cycloalkanediols and desymmetrization of meso cis-diols took place with 0.15 mol % Pd/Au (3:1)-17 under oxygen atmosphere in water to give excellent chemical and optical yields of (S)-hydroxy ketones. Various alkenes were oxidized with 0.5 mol % Pd/Au (3:1)-17 under 30 psi of oxygen in water to give the dihydroxylated products in >93% ee. Oxidation of (R)-limonene at 25 °C occurred at the C-1,2-cyclic alkene function yielding (1S,2R,4R)-dihydroxylimonene 49 in 92% yield. Importantly, cycloalkanes were oxidized with 1 mol % Cu/Au (3:1)-17 and 30% H2O2 in acetonitrile to afford chiral ketones in very good to excellent chemical and optical yields. Alkene function was not oxidized under the reaction conditions. Mechanisms were proposed for the oxidation reactions, and observed stereo- and regio-chemistry were summarized.
Enantioselective Cascade Biocatalysis via Epoxide Hydrolysis and Alcohol Oxidation: One-Pot Synthesis of (R)-α-Hydroxy Ketones from Meso- or Racemic Epoxides
Zhang, Jiandong,Wu, Shuke,Wu, Jinchuan,Li, Zhi
, p. 51 - 58 (2015/04/27)
A new type of cascade biocatalysis was developed for one-pot enantioselective conversion of a meso- or racemic epoxide to an α-hydroxy ketone in high ee via an epoxide hydrolase-catalyzed hydrolysis of the epoxide, an alcohol dehydrogenase-catalyzed oxidation of the diol intermediate, and an enzyme-catalyzed cofactor regeneration. In vitro cascade biotransformation of meso-epoxides (cyclopentene oxide 1a, cyclohexene oxide 1b, and cycloheptene oxide 1c) was achieved with cell-free extracts containing recombinant SpEH (epoxide hydrolase from Sphingomonas sp. HXN-200), BDHA (butanediol dehydrogenase from Bacillus subtilis BGSC1A1), and LDH (lactate dehydrogenase form Bacillus subtilis) or NOX (NADH oxidase from Lactobacillus brevis DSM 20054), respectively, giving the corresponding (R)-α-hydroxycyclopentanone 3a, (R)-α-hydroxycyclohexanone 3b, and (R)-α-hydroxycycloheptanone 3c in 98-99% ee and 70-50% conversion with TTN of NAD+-recycling of 5500-26000. Cascade catalysis with mixed cells of Escherichia coli (SpEH) and E. coli (BDHA-NOX) converted 100-300 mM meso-epoxides 1a-1c to (R)-α-hydroxy ketones 3a-3c in 98-99% ee and 85-57% conversion. Cells of E. coli (SpEH-BDHA-NOX) coexpressing all three enzymes were also proven as good catalysts for the cascade conversion of 100-200 mM meso-epoxides 1a-1c, giving (R)-α-hydroxy ketones 3a-3c in 98-99% ee and 79-52% conversion. The cascade biocatalysis for one-pot synthesis of α-hydroxy ketone in high ee was also successfully demonstrated with a racemic epoxide (1,2,3,4-tetrahydronaphthalene-1,2-oxide 1d) as the substrate. By using two whole-cells based approaches, (R)-α-hydroxytetralone 3d was obtained in 99% ee and 49-40% conversion from 20 to 5 mM racemic epoxide 1d. Preparative cascade biotransformation of cyclohexene oxide 1b gave (R)-α-hydroxycyclohexanone 3b in 98% ee with 70% isolated yield. The developed new type of cascade biocatalysis is enantioselective, green, and often high yielding. The concept might be generally applicable to produce other useful enantiopure α-hydroxy ketones from the corresponding meso- or racemic epoxides by cascade catalysis using appropriate enzymes. (Chemical Equation Presented).
An efficient method for selective oxidation of 1,2-diols in water catalyzed by Me2SnCl2
William, Julius M.,Kuriyama, Masami,Onomura, Osamu
, p. 19247 - 19250 (2013/10/22)
Dimethyltin(iv)dichloride-catalyzed selective oxidation of 1,2-diols in water was achieved using dibromoisocyanuric acid (DBI) or Br2 as oxidants. The catalyst activates the 1,2-diol moiety through the formation of stannylene acetal in addition to enhancing selectivity. Various cyclic and acyclic 1,2-diol substrates have been selectively oxidized affording α-hydroxyketones in good to excellent yields. This method is safe and simple in operation.
Enantioselective biooxidation of racemic trans-cyclic vicinal diols: One-pot synthesis of both enantiopure (S,S)-cyclic vicinal diols and (R)-α-hydroxy ketones
Zhang, Jiandong,Xu, Tingting,Li, Zhi
supporting information, p. 3147 - 3153 (2013/12/04)
Highly regio- and enantioselective alcohol dehydrogenases BDHA (2,3-butanediol dehydrogenase from Bacillus subtilis BGSC1A1), CDDHPm (cyclic diol dehydrogenase from Pseudomonas medocina TA5), and CDDHRh (cyclic diol dehydrogenase from Rhodococcus sp. Moj-3449) were discovered for the oxidation of racemic trans-cyclic vicinal diols. Recombinant Escherichia coli expressing BDHA was engineered as an efficient whole-cell biocatalyst for the oxidation of (±)-1,2-cyclopentanediol, 1,2-cyclohexanediol, 1,2-cycloheptane-diol, and 1,2-cyclooctanediol, respectively, to give the corresponding (R)-α-hydroxy ketones in >99% ee and (S,S)-cyclic diols in >99% ee at 50% conversion in one pot. Escherichia coli (BDHA-LDH) co-expressing lactate dehydrogenase (LDH) for intracellular regeneration of NAD+ catalyzed the regio- and enantioselective oxidation of (±)-1,2-dihydroxy-1,2,3,4- tetrahydronaphthalene to produce the corresponding (R)-α-hydroxy ketone in >99% ee and (S,S)-cyclic diol in 96% ee at 49% conversion. Preparative biotransformations were also demonstrated. Thus, a novel and useful method for the one-pot synthesis of both vicinal diols and α-hydroxy ketones in high ee was developed via high Copyright
Reactions of hydrogen peroxide with acetylacetone and 2- acetylcyclopentanone
Novikov,Shestak
, p. 2171 - 2190 (2014/11/07)
A reaction of acetylacetone with equimolar amount of concentrated aqueous H2O2 in both organic solvents (ButOH, AcOH) and water at various temperatures gave the corresponding 3,5-dihydroxy-1,2- dioxolanes with different configuration of stereogenic centers. In the pres-ence of an excess of H2O2, 3,5-dihydroxy-1,2-dioxolanes were converted to a mixture of 5-hydroperoxy-3-hydroxy-1,2-dioxolanes and further to a mixture of dimeric 1,2-dioxolan-3-ylperoxides. All the peroxides formed exist in solutions as equilibrium mixtures with the starting reagents. A prolonged reflux of solutions of 3,5-dihydroxy-1,2-dioxolanes in ButOH in the presence of a large excess of H2O2 led to the skeletal rearrangements of the substrates to a mixture of propionic acid and hydroxyacetone, which underwent further oxidative transfor-mations. Unlike acetylacetone, 2-acetylcyclopentanone reacted with H2O2 in aqueous phase or in solutions in ButOH under thermodynamic or kinetic control with the formation of the corresponding 5-hydroperoxy-3-hydroxy- 1,2-dioxolanes, rather than 3,5-dihydroxy-1,2-di-oxolanes. Thermodynamically controlled process in solution in AcOH gave a mixture of all four possible hydroperoxyhydroxy-1,2-dioxolanes. These cyclic peroxides in solutions in ButOH or AcOH readily converted to a mixture of AcOH, glutaric, α-methyladipic, and α-hydroxy-α-methyladipic acids. An active α-hydroxylation of the substrate was observed upon reflux of a solution of 2-acetylcyclopentanone and H2O2 in AcOH.
