- Synthesis of new chiral Mn(iii)-salen complexes as recoverable and reusable homogeneous catalysts for the asymmetric epoxidation of styrenes and chromenes
-
New chiral Mn(iii)-salen complexes 1a-e and 2a-e were synthesized from the reaction of C2-symmetric chiral salen ligands and Mn(CH3COO)2·4H2O under an inert atmosphere followed by aerobic oxidation. These complexes were obtained in 91-96% yields and characterized by HRMS, FT-IR, UV-visible spectroscopy, TGA, and elemental analysis. The chiral Mn(iii)-salen complexes 1a-e and 2a-e were evaluated in the asymmetric epoxidation of styrene using NaOCl as an oxidant in ethyl acetate as a green solvent. The chiral Mn(iii)-salen complexes 1b and 2b (2 mol%) catalyzed the asymmetric epoxidation of substituted styrenes and chromenes to afford the corresponding epoxides in 95-98% yields with 29-88% ee's. The catalysts 1b and 2b were recovered and reused for up to 2 and 3 runs, respectively, in the asymmetric epoxidation of styrene, and the yield of styrene oxide gradually decreased but the ee was consistent.
- Chaudhary, Pooja,Damodaran, Krishna K.,Singh, Surendra,Yadav, Geeta Devi
-
p. 1308 - 1318
(2022/02/07)
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- Structure-Guided Regulation in the Enantioselectivity of an Epoxide Hydrolase to Produce Enantiomeric Monosubstituted Epoxides and Vicinal Diols via Kinetic Resolution
-
Structure-guided microtuning of an Aspergillus usamii epoxide hydrolase was executed. One mutant, A214C/A250I, displayed a 12.6-fold enhanced enantiomeric ratio (E = 202) toward rac-styrene oxide, achieving its nearly perfect kinetic resolution at 0.8 M in pure water or 1.6 M in n-hexanol/water. Several other beneficial mutants also displayed significantly improved E values, offering promising biocatalysts to access 19 structurally diverse chiral monosubstituted epoxides (97.1 - ≥ 99% ees) and vicinal diols (56.2-98.0% eep) with high yields.
- Hou, Xiao-Dong,Hu, Bo-Chun,Hu, Die,Lei, Yu-Qing,Rao, Yi-Jian,Wu, Min-Chen,Zhang, Dong
-
supporting information
p. 1757 - 1761
(2022/03/16)
-
- The Stereoselective Oxidation of para-Substituted Benzenes by a Cytochrome P450 Biocatalyst
-
The serine 244 to aspartate (S244D) variant of the cytochrome P450 enzyme CYP199A4 was used to expand its substrate range beyond benzoic acids. Substrates, in which the carboxylate group of the benzoic acid moiety is replaced were oxidised with high activity by the S244D mutant (product formation rates >60 nmol.(nmol-CYP)?1.min?1) and with total turnover numbers of up to 20,000. Ethyl α-hydroxylation was more rapid than methyl oxidation, styrene epoxidation and S-oxidation. The S244D mutant catalysed the ethyl hydroxylation, epoxidation and sulfoxidation reactions with an excess of one stereoisomer (in some instances up to >98 %). The crystal structure of 4-methoxybenzoic acid-bound CYP199A4 S244D showed that the active site architecture and the substrate orientation were similar to that of the WT enzyme. Overall, this work demonstrates that CYP199A4 can catalyse the stereoselective hydroxylation, epoxidation or sulfoxidation of substituted benzene substrates under mild conditions resulting in more sustainable transformations using this heme monooxygenase enzyme.
- Chao, Rebecca R.,Lau, Ian C.-K.,Coleman, Tom,Churchman, Luke R.,Child, Stella A.,Lee, Joel H. Z.,Bruning, John B.,De Voss, James J.,Bell, Stephen G.
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p. 14765 - 14777
(2021/09/14)
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- Diastereoselective Alkene Hydroesterification Enabling the Synthesis of Chiral Fused Bicyclic Lactones
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Palladium-catalysed diastereoselective hydroesterification of alkenes assisted by the coordinative hydroxyl group in the substrate afforded a variety of chiral γ-butyrolactones bearing two stereocenters. Employing the carbonylation-lactonization products as the key intermediates, the route from the alkenes with single chiral center to chiral THF-fused bicyclic γ-lactones containing three stereocenters was developed.
- Shi, Zhanglin,Shen, Chaoren,Dong, Kaiwu
-
supporting information
p. 18039 - 18042
(2021/11/16)
-
- A new clade of styrene monooxygenases for (R)-selective epoxidation
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Styrene monooxygenases (SMOs) are excellent enzymes for the production of (S)-enantiopure epoxides, but so far, only one (R)-selective SMO has been identified with a narrow substrate spectrum. Mining the NCBI non-redundant protein sequences returned a new distinct clade of (R)-selective SMOs. Among them,SeStyA fromStreptomyces exfoliatus,AaStyA fromAmycolatopsis albispora, andPbStyA fromPseudonocardiaceaewere carefully characterized and found to convert a spectrum of styrene analogues into the corresponding (R)-epoxides with up to >99% ee. Moreover, site 46 (AaStyA numbering) was identified as a critical residue that affects the enantioselectivity of SMOs. Phenylalanine at site 46 was required for the (R)-selective SMO to endow excellent enantioselectivity. The identification of new (R)-selective SMOs would add a valuable green alternative to the synthetic tool box for the synthesis of enantiopure (R)-epoxides.
- Xiao, Hu,Dong, Shuang,Liu, Yan,Pei, Xiao-Qiong,Lin, Hui,Wu, Zhong-Liu
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p. 2195 - 2201
(2021/04/12)
-
- Asymmetric azidohydroxylation of styrene derivatives mediated by a biomimetic styrene monooxygenase enzymatic cascade
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Enantioenriched azido alcohols are precursors for valuable chiral aziridines and 1,2-amino alcohols, however their chiral substituted analogues are difficult to access. We established a cascade for the asymmetric azidohydroxylation of styrene derivatives leading to chiral substituted 1,2-azido alcohols via enzymatic asymmetric epoxidation, followed by regioselective azidolysis, affording the azido alcohols with up to two contiguous stereogenic centers. A newly isolated two-component flavoprotein styrene monooxygenase StyA proved to be highly selective for epoxidation with a nicotinamide coenzyme biomimetic as a practical reductant. Coupled with azide as a nucleophile for regioselective ring opening, this chemo-enzymatic cascade produced highly enantioenriched aromatic α-azido alcohols with up to >99% conversion. A bi-enzymatic counterpart with halohydrin dehalogenase-catalyzed azidolysis afforded the alternative β-azido alcohol isomers with up to 94% diastereomeric excess. We anticipate our biocatalytic cascade to be a starting point for more practical production of these chiral compounds with two-component flavoprotein monooxygenases.
- Franssen, Maurice C. R.,Hollmann, Frank,Martínez-Montero, Lía,Paul, Caroline E.,Süss, Philipp,Schallmey, Anett,Tischler, Dirk
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p. 5077 - 5085
(2021/08/16)
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- Peroxygenase-Catalysed Epoxidation of Styrene Derivatives in Neat Reaction Media
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Biocatalytic oxyfunctionalisation reactions are traditionally conducted in aqueous media limiting their production yield. Here we report the application of a peroxygenase in neat reaction conditions reaching product concentrations of up to 360 mM.
- Alcalde, Miguel,Arends, Isabel W. C. E.,Hollmann, Frank,Paul, Caroline E.,Rauch, Marine C. R.,Tieves, Florian
-
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- Photoenzymatic epoxidation of styrenes
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Two-component-diffusible-flavomonooxygenases are versatile biocatalysts for selective epoxidation-, hydroxylation- or halogenation reactions. Their complicated molecular architecture can be simplified using photochemical regeneration of the catalytically
- Van Schie, Morten M. C. H.,Paul, Caroline E.,Arends, Isabel W. C. E.,Hollmann, Frank
-
supporting information
p. 1790 - 1792
(2019/02/12)
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- Immobilization of Amano lipase from Pseudomonas fluorescens on silk fibroin spheres: an alternative protocol for the enantioselective synthesis of halohydrins
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The search for a new, efficient, cheaper and sustainable matrix for lipase immobilization is a growing area in biotechnology. Amano lipase from Pseudomonas fluorescens was immobilized on silk fibroin spheres and used in the enzymatic kinetic resolution of halohydrins, to obtain optically active epoxides (up to 99% ee), important precursors in the synthesis of derivative antifungal azoles. This paper reinforces the versatility of silk fibroin as a support for heterogeneous catalysts.
- Ferreira, Irlon M.,Yoshioka, Sergio A.,Comasseto, Jo?o V.,Porto, André L. M.
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p. 12650 - 12658
(2017/03/11)
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- Highly Enantioselective Hydrosilylation of Ketones Catalyzed by a Chiral Oxazaborolidinium Ion
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A highly enantioselective hydrosilylation of ketones was developed for the synthesis of a variety of chiral secondary alcohols. In the presence of a chiral oxazaborolidinium ion (COBI) catalyst, the reaction proceeded with good yields (up to 99%) with excellent enantioselectivities (up to 99% ee).
- Kang, Byung Chul,Shin, Sung Ho,Yun, Jaesook,Ryu, Do Hyun
-
supporting information
p. 6316 - 6319
(2017/12/08)
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- Biocatalytic Formal Anti-Markovnikov Hydroamination and Hydration of Aryl Alkenes
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Biocatalytic anti-Markovnikov alkene hydroamination and hydration were achieved based on two concepts involving enzyme cascades: epoxidation-isomerization-amination for hydroamination and epoxidation-isomerization-reduction for hydration. An Escherichia coli strain coexpressing styrene monooxygenase (SMO), styrene oxide isomerase (SOI), ω-transaminase (CvTA), and alanine dehydrogenase (AlaDH) catalyzed the hydroamination of 12 aryl alkenes to give the corresponding valuable terminal amines in high conversion (many ≥86%) and exclusive anti-Markovnikov selectivity (>99:1). Another E. coli strain coexpressing SMO, SOI, and phenylacetaldehyde reductase (PAR) catalyzed the hydration of 12 aryl alkenes to the corresponding useful terminal alcohols in high conversion (many ≥80%) and very high anti-Markovnikov selectivity (>99:1). Importantly, SOI was discovered for stereoselective isomerization of a chiral epoxide to a chiral aldehyde, providing some insights on enzymatic epoxide rearrangement. Harnessing this stereoselective rearrangement, highly enantioselective anti-Markovnikov hydroamination and hydration were demonstrated to convert α-methylstyrene to the corresponding (S)-amine and (S)-alcohol in 84-81% conversion with 97-92% ee, respectively. The biocatalytic anti-Markovnikov hydroamination and hydration of alkenes, utilizing cheap and nontoxic chemicals (O2, NH3, and glucose) and cells, provide an environmentally friendly, highly selective, and high-yielding synthesis of terminal amines and alcohols.
- Wu, Shuke,Liu, Ji,Li, Zhi
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p. 5225 - 5233
(2017/08/17)
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- Synthesis of enantiopure 1,2-azido and 1,2-amino alcohols via regio- and stereoselective ring-opening of enantiopure epoxides by sodium azide in hot water
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A practical and convenient method for the efficient and regio- and stereoselective ring-opening of enantiopure monosubstituted epoxides by sodium azide under hydrolytic conditions is reported. The ring-opening of enantiopure styryl and pyridyl (S)-epoxides by N3- in hot water takes place preferentially at the internal position with complete inversion of configuration to produce (R)-2-azido ethanols with up to 99% enantio- and regioselectivity, while the (S)-adamantyl oxirane provides mainly the (S)-1-adamantyl-2-azido ethanol in excellent yield. In general, 1,2-amino ethanols were obtained in high yield and excellent enantiopurity by the reduction of the chiral 1,2-azido ethanols with PPh3 in water/THF, and then converted into the Boc or acetamide derivatives.
- Wang, Hai-Yang,Huang, Kun,De Jesús, Melvin,Espinosa, Sandraliz,Pi?ero-Santiago, Luis E.,Barnes, Charles L.,Ortiz-Marciales, Margarita
-
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- The Activation of Carboxylic Acids via Self-Assembly Asymmetric Organocatalysis: A Combined Experimental and Computational Investigation
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The heterodimerizing self-assembly between a phosphoric acid catalyst and a carboxylic acid has recently been established as a new activation mode in Br?nsted acid catalysis. In this article, we present a comprehensive mechanistic investigation on this activation principle, which eventually led to its elucidation. Detailed studies are reported, including computational investigations on the supramolecular heterodimer, kinetic studies on the catalytic cycle, and a thorough analysis of transition states by DFT calculations for the rationalization of the catalyst structure-selectivity relationship. On the basis of these investigations, we developed a kinetic resolution of racemic epoxides, which proceeds with high selectivity (up to s = 93), giving the unreacted epoxides and the corresponding protected 1,2-diols in high enantiopurity. Moreover, this approach could be advanced to an unprecedented stereodivergent resolution of racemic α-chiral carboxylic acids, thus providing access to a variety of enantiopure nonsteroidal anti-inflammatory drugs and to α-amino acid derivatives.
- Monaco, Mattia Riccardo,Fazzi, Daniele,Tsuji, Nobuya,Leutzsch, Markus,Liao, Saihu,Thiel, Walter,List, Benjamin
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supporting information
p. 14740 - 14749
(2016/11/18)
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- Azidolysis of epoxides catalysed by the halohydrin dehalogenase from Arthrobacter sp. AD2 and a mutant with enhanced enantioselectivity: an (S)-selective HHDH
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Halohydrin dehalogenase from Arthrobacter sp. AD2 catalysed azidolysis of epoxides with high regioselectivity and low to moderate (S)-enantioselectivity (E?=?1–16). Mutation of the asparagine 178 to alanine (N178A) showed increased enantioselectivity towards styrene oxide derivatives and glycidyl ethers. Conversion of aromatic epoxides was catalysed by HheA-N178A with complete enantioselectivity, however the regioselectivity was reduced. As a result of the enzyme-catalysed reaction, enantiomerically pure (S)-β-azido alcohols and (R)-α-azido alcohols (ee???99%) were obtained.
- Mikleu?evi?, Ana,Primo?i?, Ines,Hrenar, Tomica,Salopek-Sondi, Branka,Tang, Lixia,Elenkov, Maja Majeri?
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p. 930 - 935
(2016/09/13)
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- Self-supported chiral polymeric MnIII salen complexes as highly active and recyclable catalysts for epoxidation of nonfunctionalized olefins
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Abstract A series of self-supported chiral polymeric MnIII N,N′-ethylenebis(salicylimine) (salen) complexes were synthesized through metalation of the corresponding salen ligands obtained by condensation of several bis/tris-aldehydes with (1R,2
- Roy, Tamal,Kureshy, Rukhsana I.,Khan, Noor-Ul H.,Abdi, Sayed H. R.,Bajaj, Hari C.
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p. 1038 - 1044
(2015/06/08)
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- Nonenzymatic Regeneration of Styrene Monooxygenase for Catalysis
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Styrene monooxygenase (SMO) is a two-component flavoprotein catalyzing the selective epoxidation of various C=C double bonds. For cell-free catalysis, traditionally a cascade of NAD(P)H:flavin oxidoreductase, nicotinamide cofactor (NADH), and NADH regener
- Paul, Caroline E.,Tischler, Dirk,Riedel, Anika,Heine, Thomas,Itoh, Nobuya,Hollmann, Frank
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p. 2961 - 2965
(2015/09/08)
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- Enhanced turnover rate and enantioselectivity in the asymmetric epoxidation of styrene by new T213G mutants of CYP 119
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New CYP 119 T213G mutants were constructed and characterized. Introduction of the T213G mutation into the wild-type CYP 119 significantly enhances the turnover rate for the peroxide-dependent styrene epoxidation 4.4-fold to 346.2 min-1, and the
- Zhang, Chun,Li, Jing,Yang, Bo,He, Fang,Yang, Sheng-Yong,Yu, Xiao-Qi,Wang, Qin
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p. 27526 - 27531
(2014/07/21)
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- A mononuclear manganese complex of a tetradentate nitrogen ligand - Synthesis, characterizations, and application in the asymmetric epoxidation of olefins
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A new chiral manganese complex (C1) bearing a tetradentate nitrogen ligand containing chiral bipyrrolidine and benzimidazole moieties was prepared. The structure of C1 was confirmed by ESI-MS and crystallography. This manganese complex is an active catalyst for the asymmetric epoxidation of various olefins with excellent conversion (up to 99%) and high enantiomeric excess (up to 96%ee) with hydrogen peroxide as the oxidant in the presence of 2-ethylhexanoic acid or acetic acid. Compared with previous structurally similar manganese complexes with different diamine backbones (C2, cyclohexanediamine; C3, diamine from L-proline), C1 showed improved asymmetric induction, especially for simple olefins such as styrene derivatives and substituted chromene. The possible reasons for the improvement of the ee values are discussed in the text on the basis of the crystal structures of the manganese complexes.
- Shen, Duyi,Miao, Chengxia,Wang, Shoufeng,Xia, Chungu,Sun, Wei
-
supporting information
p. 5777 - 5782
(2015/02/19)
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- Engineered P450pyr monooxygenase for asymmetric epoxidation of alkenes with unique and high enantioselectivity
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A triple mutant of P450pyr monooxygenase (P450pyrTM) catalysed the epoxidation of several para-substituted styrenes as the first enzyme showing high (R)-enantioselectivity and high conversion, demonstrated a broad substrate range, and showed high enantioselectivity for the epoxidation of an unconjugated 1,1-disubstituted alkene, 2-methyl-3-phenyl-1-propene, and a cyclic alkene, N-phenoxycarbonyl-1,2,5,6-tetrahydropyridine, respectively.
- Li, Aitao,Liu, Ji,Pham, Son Q.,Li, Zhi
-
supporting information
p. 11572 - 11574
(2013/12/04)
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- Efficient biocatalysis for the production of enantiopure (S)-epoxides using a styrene monooxygenase (SMO) and Leifsonia alcohol dehydrogenase (LSADH) system
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Herein we report the production of enantiopure epoxides through biocatalysis using recombinant Escherichia coli cells expressing Rhodococcus sp. ST-10 styrene monooxygenase (SMO) and Leifsonia sp. S749 alcohol dehydrogenase (LSADH) genes are described. Rhodococcus sp. ST-10 SMO catalyzed the epoxidation of various alkenes, including styrene derivatives, vinyl pyridines, and linear alkenes, to give (S)-epoxides. NADH was regenerated by the reduction of NAD + by LSADH with 2-propanol. The E. coli biocatalyst was used in an aqueous/organic biphasic reaction system and the reaction conditions were optimized. Under the optimized conditions, 170 mM of (S)-styrene oxide was obtained from styrene in the organic phase with excellent enantiomeric excess (99.8%). This biocatalytic process was used to synthesize various (S)-epoxides.
- Toda, Hiroshi,Imae, Ryouta,Itoh, Nobuya
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p. 1542 - 1549
(2013/02/21)
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- Chiral epoxides via borane reduction of 2-haloketones catalyzed by spiroborate ester: Application to the synthesis of optically pure 1,2-hydroxy ethers and 1,2-azido alcohols
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An enantioselective borane-mediated reduction of a variety of 2-haloketones with 10% spiroaminoborate ester 1 as catalyst is described. By a simple basic workup of 2-halohydrins, optically active epoxides are obtained in high yield and with excellent enantiopurity (up to 99% ee). Ring-opening of oxiranes with phenoxides or sodium azide is investigated under different reaction conditions affording nonracemic 1,2-hydroxy ethers and 1,2-azido alcohols with excellent enantioselectivity (99% ee) and in good to high chemical yield. 2011 American Chemical Society.
- Huang, Kun,Wang, Haiyang,Stepanenko, Viatcheslav,De Jesus, Melvin,Torruellas, Carilyn,Correa, Wildeliz,Ortiz-Marciales, Margarita
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p. 1883 - 1886
(2011/06/20)
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- On the configurational stability of α-lithiated sulfurated styrene oxides: Synthetic and mechanistic aspects
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The configurational stability of some sulfurated styrene oxides has been investigated. Chemical studies have shown that in THF at 157 K α-lithiated ortho-and paraphenylthiostyrene oxides are configurationally unstable and undergo a fast racemization on the time scale of the reaction, whereas α-lithiated meta-phenylthiostyrene oxide retains its stereochemical integrity for at least 60 min. The deprotonation-trapping methodology has also been employed for the preparation of a sulfurated β-aminoalcohol effective for the fight against phytopathogenic fungi. Copyright Taylor and Francis Group, LLC.
- Capriati, Vito,Dammacco, Mariangela,Florio, Saverio,Perna, Filippo M.,Salomone, Antonio
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scheme or table
p. 1274 - 1277
(2011/09/15)
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- Biaryl-bridged salalen ligands and their application in titanium-catalyzed asymmetric epoxidation of olefins with aqueous H2O2
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A series of biaryl-bridged salalen ligands together with their titanium complexes have been designed and synthesized. The Ti complexes could serve as highly efficient catalysts for the asymmetric epoxidation of a wide range of olefins, giving the corresponding epoxides with high ee values. A biaryl-bridged salalen titanium complex was developed and used in the enantioselective epoxidation of a range of olefins with aqueous hydrogen peroxide as the oxidant. Notably, the intramolecular dinuclear Ti catalyst possessing a biaryl bridge is highly efficient for the reaction, especially using terminal aromatic olefins as substrates.
- Xiong, Donglu,Hu, Xiaoxue,Wang, Shoufeng,Miao, Cheng-Xia,Xia, Chungu,Sun, Wei
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experimental part
p. 4289 - 4292
(2011/09/15)
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- PROCESS FOR PRODUCING OPTICALLY ACTIVE CIS-SILYL OLEFIN OXIDE COMPOUND
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The present invention provides an efficient production method of an optically active cis-silylolefin oxide compound useful as an intermediate for various compounds. A production method of an optically active cis-silylolefin oxide compound by subjecting an
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Page/Page column 17
(2010/12/29)
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- Synthesis of salan (salalen) ligands derived from binaphthol for titanium-catalyzed asymmetric epoxidation of olefins with aqueous H2O2
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A series of chiral salan (salalen) ligands, easily prepared from the aldehyde derived from chiral binaphthol, are effective ligands for the titanium-catalyzed asymmetric epoxidation of olefins with aqueous H2O2 as the oxidant. One of
- Xiong, Donglu,Wu, Mei,Wang, Shoufeng,Li, Fuwei,Xia, Chungu,Sun, Wei
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experimental part
p. 374 - 378
(2010/06/14)
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- Styrene monooxygenase from Pseudomonas sp. LQ26 catalyzes the asymmetric epoxidation of both conjugated and unconjugated alkenes
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A novel styrene monooxygenase (SMO) was isolated from Pseudomonas sp. LQ26, a styrene degrader from activated sludge. Sequence alignment demonstrated that it was the most distant member of all SMOs originating from the genus of Pseudomonas. The substrate spectrum of this enzyme extended beyond typical SMO substrates to 1-allylbenzene analogues, previously reported as non-substrates for the SMO from Pseudomonas fluorescens ST. The results demonstrate for the first time the asymmetric epoxidation of both conjugated and unconjugated alkenes catalyzed by SMO and suggest that a much broader substrate spectrum is expected for SMOs.
- Lin, Hui,Qiao, Jing,Liu, Yan,Wu, Zhong-Liu
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experimental part
p. 236 - 241
(2011/02/22)
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- Asymmetric epoxidation of styrenes catalyzed by molybdenum complexes with amino alcohol ligands
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Two common amino alcohols, prolinol and isolucinol, and their derivatives have been screened to coordinate with MoO2(acac)2 to form in situ catalysts for asymmetric epoxidation of styrenes with the highest enantioselectivity of 84% for 4-fluoro-styrene under the optimized reaction conditions.
- Wang, Yi,Wu, Zhiqing,Li, Zhengkai,Zhou, Xiang-Ge
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experimental part
p. 2509 - 2511
(2009/09/05)
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- Asymmetric epoxidation of olefins with chiral bioinspired manganese complexes
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Image Presented A novel series of chiral tetradentate N4 ligands together with their manganese complexes have been designed and synthesized. With 1 mol % manganese catalyst loading, the enantioselective epoxidation of olefins proceeds with nearly full conversion and enantiomeric excess values of up to 89 % for the first time.
- Wu, Mei,Wang, Bin,Wang, Shoufeng,Xia, Chungu,Sun, Wei
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supporting information; experimental part
p. 3622 - 3625
(2011/02/22)
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- Highly enantioselective epoxidation of cis-alkenylsilanes
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A general and highly enantioselective method for the epoxidation of cis-alkenylsilanes was developed, in which the epoxysilanes were obtained with complete enantioselectivity in the presence of 0.5 2 mol% of Ti (salalen) complex 1. cis-Alkenylsilanes were
- Matsumoto, Kazuhiro,Kubo, Takuya,Katsuki, Tsutomu
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supporting information; experimental part
p. 6573 - 6575
(2010/02/28)
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- 3-METHYL-2- ( (2S) -2- (4- (3-METHYL-L, 2, 4-0XADIAZ0L-5-YL) PHENYL) MORPHOLINO) -6- (PYRIMIDIN-4-YL) PYRIMIDIN-4 (3H) -ONE AS TAU PROTEIN KINASE INHIBITOR
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A compound represented by the formula (I) or a pharmaceutically acceptable salt thereof: which is used for preventive and/or therapeutic treatment of a disease caused by abnormal activity of tau protein kinase 1 such as a neurodegenerative diseases (e.g.
- -
-
Page/Page column 11; 15
(2009/04/25)
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- 6-PYRIMIDINYL-PYRIMID-2-ONE DERIVATIVE
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A compound represented by the formula (I) or a pharmaceutically acceptable salt thereof: which is used for preventive and/or therapeutic treatment of a disease caused by abnormal activity of tau protein kinase 1 such as a neurodegenerative diseases (e.g.
- -
-
Page/Page column 10-11; 15
(2009/04/25)
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- 2-SUBSTITUTED-6-HETEROCYCLIC PYRIMIDONE DERIVATIVES AS TAU PROTEIN KINASE 1 INHBITORS
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A compound represented by the formula (I), an optically active isomer thereof, or a pharmaceutical acceptable salt thereof: wherein each R1 represents hydrogen atom or the like; X represents oxygen atom or the like; A represents a C3
- -
-
Page/Page column 21-22
(2008/12/07)
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- A novel method for the synthesis of chiral epoxides from styrene derivatives using chiral acids in presence of Pseudomonas lipase G6 [PSL G6] and hydrogen peroxide
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Chiral epoxidation of styrene and its derivatives was carried out using series of chiral acids and urea hydrogen peroxide (UHP) or aqueous hydrogen peroxide (50%) in two phases under the catalytic influence of immobilized Pseudomonas lipase G6 [PSL G6] at 25-55 °C. A moderate to good yield and enantioselectivities of chiral epoxides were obtained.
- Sarma, Kuladip,Bhati, Nishi,Borthakur, Naleen,Goswami, Amrit
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p. 8735 - 8741
(2008/02/09)
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- INTERMEDIATE COMPOUND FOR SYNTHESIZING PHARMACEUTICAL AGENT AND PRODUCTION METHOD THEREOF
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The present invention relates to a production method of an optically active morpholine compound represented by the formula 10, which includes the following steps: wherein each symbol is as defined in the specification. The present invention also relates t
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-
Page/Page column 86
(2008/06/13)
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- (S)-dimethylsulfonium(p-tolylsulfinyl)methylide: A new chiral sulfonium ylide and its use in asymmetric epoxidation
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The title optically active sulfonium ylide was prepared by methylation of easily available (-)-(S)-p-tolylmethylthiomethyl-sulfoxide and subsequent deprotonation. Its reaction with aldehydes gave α,β-epoxy sulfoxides with full enantioselectivity and moder
- Midura, Wanda H.
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p. 733 - 736
(2007/10/03)
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- Effective asymmetric epoxidation of styrenes by chiral dioxirane
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High enantioselectivity (80-92% enantiomeric excess (ee)) has been obtained for the epoxidation of various styrenes using an easily prepared ketone (4) catalyst.
- Goeddel, David,Shu, Lianhe,Yuan, Yi,Wong, O. Andrea,Wang, Bin,Shi, Yian
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p. 1715 - 1717
(2007/10/03)
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- Chiral styrene oxides from α-haloacetophenones using NaBH4 and TarB-NO2, a chiral Lewis acid
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High enantioselectivities are obtained for the preparation of chiral styrene oxides through reduction of α-haloacetophenones using TarB-NO 2 reagent and the inexpensive and mild reducing agent NaBH 4. The epoxides are easily obtained in up to 95% ee through routine acid-base workup of the product alcohols. Either the (R) or (S) epoxide can be obtained by using the appropriate l- or d-tartaric acid starting material in the TarB-NO2 reagent.
- Cordes, David B.,Kwong, Tracey J.,Morgan, Kellie A.,Singaram, Bakthan
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p. 349 - 351
(2007/10/03)
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- COMPOUNDS WHICH POTENTIATE GLUTAMATE RECEPTOR AND USES THEREOF IN MEDICINE
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This invention relates to potentiation of the glutamate receptor by novel compounds of formula (I): The invention also relates to the use of the derivatives in treating diseases and conditions mediated by potentiation of the glutamate receptor, compositio
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Page/Page column 41
(2008/06/13)
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- 2-MORPHOLINO-4-PYRIMIDONE COMPOUND
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A compound represented by the formula (I), an optically active isomer thereof, or a pharmaceutical acceptable salt thereof: wherein X represents CH or N; 1 represents a C1-C12 alkyl; R2 represents a hydrogen atom, or the like; R' represents a C1-C6 alkyl or the like; q represents 0 or an integer of 1 to 7; Y represents a C1-C6 alkyl or the like; p represents 0 or an integer of 1 to 5; R represents a 2,3-dihydroindolyl or the like, which is used for preventive and/or therapeutic treatment of a disease caused by tau protein kinase 1 hyperactivity such as a neurodegenerative diseases (e.g. Alzheimer disease).
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Page/Page column 66
(2008/06/13)
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- PYRIMIDONE COMPOUND
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A compound represented by the formula (I), an optically active isomer thereof, or a pharmaceutical acceptable salt thereof:wherein R1 represents a C1-C12 alkyl; R2 represents a hydrogen atom or the like; R3 represents a halogen or the like; q represents an integer of 1 to 7; R4 represents a halogen or the like; p represents 0 or an integer of 1 to 5; R5 represents a C6-C10 aryl, a heterocycle or the like; and X represents oxygen, NH, or the like, which is used for preventive and/or therapeutic treatment of a disease caused by tau protein kinase 1 hyperactivity such as a neurodegenerative diseases (e.g. Alzheimer disease).
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Page/Page column 126
(2008/06/13)
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- BIARYL HETEROCYCLIC COMPOUNDS AND METHODS OF MAKING AND USING THE SAME
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The present invention relates generally to the field of anti-infective, anti-proliferative, anti-inflammatory, and prokinetic agents. More particularly, the invention relates to a family of tricyclic compounds that are useful as such agents.
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Page/Page column 54; 55
(2010/10/20)
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- Enantioselective hydrolysis of various substituted styrene oxides with Aspergillus Niger CGMCC 0496
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Enantioselective biohydrolysis of various substituted styrene oxides using whole fungus cells of Aspergillus niger CGMCC 0496 are described. The results show not only para- but also some ortho- substituted styrene oxides can achieve high enantioselectivity during the hydrolysis.
- Jin, Hao,Li, Zu-Yi,Dong, Xiao-Wei
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p. 408 - 414
(2007/10/03)
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- Asymmetric catalytic synthesis of enantiopure N-protected 1,2-amino alcohols
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(Chemical Equation Presented) The asymmetric aminolytic kinetic resolution (AKR) of racemic terminal epoxides using carbamates as the nucleophile catalyzed by (salen)CoIII complex provides a practical and straightforward method for the synthesis of both aliphatic and aromatic N-Boc- or N-Cbz-protected 1,2-amino alcohols in almost enantiomerically pure form (ee ≥ 99%). The AKR uses an easily accessible catalyst and inexpensive starting materials, and the reactions are conveniently carried out at room temperature under an air atmosphere.
- Bartoli, Giuseppe,Bosco, Marcella,Carlone, Armando,Locatelli, Manuela,Melchiorre, Paolo,Sambri, Letizia
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p. 3973 - 3975
(2007/10/03)
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- Stereospecific biocatalytic epoxidation: The first example of direct regeneration of a FAD-dependent monooxygenase for catalysis
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Catalysis for chemical synthesis by cell-free monooxygenases necessitates an efficient and robust in situ regeneration system to supply the enzyme with reducing equivalents. We report on a novel approach to directly regenerate flavin-dependent monooxygena
- Hollmann, Frank,Lin, Po-Chi,Witholt, Bernard,Schmid, Andreas
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p. 8209 - 8217
(2007/10/03)
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- Stereo- and enantioselective alkene epoxidations: A comparative study of D4- and D2-symmetric homochiral trans-dioxoruthenium(VI) porphyrins
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The mechanism of stoichiometric enantioselective alkene epoxidations by the D4- and D2-symmetric homochiral trans-dioxoruthenium(VI) porphyrins, [RuVI(D4-Por*)O2] (1) and [RuVI(D2-Por*)O2] (2a), in the presence of pyrazole (Hpz) was studied by UV/ Vis spectrophotometry and analysis of the organic products. The enantioselectivity of styrene oxidations is more susceptible to steric effects than to substituent electronic effects. Up to 72% ee was achieved for epoxidation of 3-substituted and cis-disubstituted styrenes by employing 1 as the oxidant, whereas entantioselectivities of only 20-40 % were obtained in the reactions with 2-substituted and trans-disubstituted styrenes. Complex 2a oxidized 2-substituted styrenes to their epoxides in up to 88% ee. Its reactions with transalkenes are more enantioselective (67 % ee) than with the cis-alkenes (40 % ee). Based on a two-dimensional NOESY NMR study, 2a was found to adopt a more open conformation in benzene than in dichloromethane, which explains the observed solvent-dependent enantioselectivity of its reactions with alkenes. The oxidation of aromatic alkenes by the chiral dioxoruthenium(VI) porphyrins proceeds through the ratelimiting formation of a benzylic radical intermediate; the observed enantioselectivity (eeobs) depends on both the facial selectivity of the first C-O bond formation step and the diastereoselectivity of the subsequent epoxide ring closure. To account for the observed facial selection, "side-on" and "top-on" approach transition state models are examined (see: B. D. Brandes, E. N. Jacobsen, Tetrahedron Lett. 1995, 36, 5123).
- Zhang, Rui,Yu, Wing-Yiu,Sun, Hong-Zhe,Liu, Wei-Sheng,Che, Chi-Ming
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p. 2495 - 2507
(2007/10/03)
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- Aralkylation of guanosine with para-substituted styrene oxides
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To probe mechanisms of nucleoside aralkylation, product distributions and product stereochemistries were determined in reactions of optically active p-methyl- and p-bromostyrene oxide with guanosine. The proportion of 7-, N2-, and O6
- Barlow, Thomas,Dipple, Anthony
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- Remarkable Effects of Metal, Solvent, and Oxidant on Metalloporphyrin-Catalyzed Enantioselective Epoxidation of Olefins
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Three metal complexes of one particular homochiral porphyrin were investigated as catalysts for enantioselective epoxidation of unfunctionalized olefins under various reaction conditions. Much better results were obtained with the iron and ruthenium compl
- Gross, Zeev,Ini, Santiago
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p. 5514 - 5521
(2007/10/03)
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- Microbiological transformations. 33. Fungal epoxide hydrolases applied to the synthesis of enantiopure para-substituted styrene oxides. A mechanistic approach
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The biohydrolysis of differently para-substituted styrene oxide derivatives was studied, using whole cells of the fungi Aspergillus niger or Beauveria sulfurescens. These microorganisms proved to be equipped with epoxide hydrolases which are able to achieve these hydrolyses with high enantioselectivity. This allowed the preparation of the optically active epoxides and of the corresponding vicinal diols which were obtained with good to excellent enantiomeric purity. These two microorganisms proved to be enantiocomplementary. A mechanistic study, carried out using a crude lyophilized enzymatic extract from A. niger, indicated via Hammet coefficient plotting that this hydrolysis is very probably due to a general base-catalyzed process.
- Pedragosa-Moreau,Morisseau,Zylber,Archelas,Baratti,Furstoss
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p. 7402 - 7407
(2007/10/03)
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- Enantioselective Epoxidation of Styrene Derivatives by Chloroperoxidase Catalysis
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Chloroperoxidase catalysed epoxidation of styrene derivatives by t-BuOOH preferentially gives (R) oxides with ee values between 28 and 68percent.The data support the view of oxygen delivery from the ferryl oxygen directly to the substrate.
- Colonna, Stefano,Gaggero, Nicoletta,Casella, Luigi,Carrea, Giacomo,Pasta, Piero
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p. 1325 - 1330
(2007/10/02)
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