- Diaminosilane-functionalized on silicate-stabilised hydrotalcite (MA-HTSi-DA): As potential catalyst for nitro-aldol condensation
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Diaminosilane was introduced into silicate-anion-intercalated hydrotalcite (HT-Si) using a post-synthesis method. The resulting functionalized materials possess surface basicity. The textural properties of the functionalized materials were systematically investigated through powder XRD, FTIR and MAS-NMR studies. The diamine-functionalized materials showed very good catalytic activity for the nitro-aldol condensation of benzaldehyde and nitromethane under solvent-free conditions. The materials showed comparable catalytic activity upon recycling.
- Thangaraj, Baskaran,Jayaraj, Christopher,Srinivasan, Radhakrishnan,Ayyamperumal, Sakthivel
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Read Online
- Synthesis of DPA-triazole structures and their application as ligand for metal catalyzed organic reactions
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In this work, the use of DPA-triazole (DPA = dipicolylamine) molecules as ligands for metal catalyzed organic reactions has been investigated. A small library of ligands has been prepared by a CuAAC (click reaction) between propargyl-DPA and different azi
- Colombo Dugoni, Greta,Sacchetti, Alessandro,Urra Mancilla, Carolina
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- One-Pot Enzyme Cascade Catalyzed Asymmetrization of Primary Alcohols: Synthesis of Enantiocomplementary Chiral β-Nitroalcohols
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Biocatalytic asymmetrization of inexpensive and stable primary alcohols to prepare enantioenriched β-nitroalcohols is an important development in green chemistry for the production of chiral pharmaceutical intermediates. Herein, we report a one-pot, two-step cascade reaction sequence in which first benzylic alcohols were oxidized to produce corresponding benzaldehydes using horse liver alcohol dehydrogenase (HLADH). The in situ generated aldehydes were then reacted in a biphasic medium with nitromethane by Arabidopsis thaliana hydroxynitrile lyase (AtHNL) or Baliospermum montanum HNL (BmHNL) catalyzed Henry reaction to produce stereoselective β-nitroalcohols with (R) or (S) configuration, respectively. Using HLADH-AtHNL, (R)-β-nitroalcohols were obtained in up to 64% conversion, and HLADH-BmHNL, (S)-β-nitroalcohols in up to 70% conversion, while in both cases excellent stereoselectivity (up to >99% ee) was achieved. The concept was proven by functionalization of sp3 C?H bond of ten simple achiral benzylic alcohols to enantiocomplementary chiral β-nitroalcohols. (Figure presented.).
- Chatterjee, Ayon,Kumar Padhi, Santosh,Rao, D. H. Sreenivasa
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supporting information
p. 5310 - 5318
(2021/10/02)
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- Production of (S)-β-Nitro Alcohols by Enantioselective C?C Bond Cleavage with an R-Selective Hydroxynitrile Lyase
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Hydroxynitrile lyase (HNL)-catalysed stereoselective synthesis of β-nitro alcohols from aldehydes and nitroalkanes is considered an efficient biocatalytic approach. However, only one S-selective HNL—Hevea brasiliensis (HbHNL)—exists that is appropriate for the synthesis of (S)-β-nitro alcohols from the corresponding aldehydes. Further, synthesis catalysed by HbHNL is limited by low specific activity and moderate yields. We have prepared a number of (S)-β-nitro alcohols, by kinetic resolution with the aid of an R-selective HNL from Arabidopsis thaliana (AtHNL). Optimization of the reaction conditions for AtHNL-catalysed stereoselective C?C bond cleavage of racemic 2-nitro-1-phenylethanol (NPE) produced (S)-NPE (together with benzaldehyde and nitromethane, largely from the R enantiomer) in up to 99 % ee and with 47 % conversion. This is the fastest HNL-catalysed route known so far for the synthesis of a series of (S)-β-nitro alcohols. This approach widens the application of AtHNL for the synthesis not only of (R)- but also of (S)-β-nitro alcohols from the appropriate substrates. Without the need for the discovery of a new enzyme, but rather by use of a retro-Henry approach, it was used to generate a number of (S)-β-nitro alcohols by taking advantage of the substrate selectivity of AtHNL.
- Rao, D. H. Sreenivasa,Padhi, Santosh Kumar
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p. 371 - 378
(2019/01/08)
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- Ketoreductase catalyzed stereoselective bioreduction of α-nitro ketones
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We report here the stereoselective bioreduction of α-nitro ketones catalyzed by ketoreductases (KREDs) with publicly known sequences. YGL039w and RasADH/SyADH were able to reduce 23 class I substrates (1-aryl-2-nitro-1-ethanone (1)) and ten class II substrates (1-aryloxy-3-nitro-2-propanone (4)) to furnish both enantiomers of the corresponding β-nitro alcohols, with good-to-excellent conversions (up to >99%) and enantioselectivities (up to >99% ee) being achieved in most cases. To the best of our knowledge, KRED-mediated reduction of class II α-nitro ketones (1-aryloxy-3-nitro-2-propanone (4)) is unprecedented. Select β-nitro alcohols, including the synthetic intermediates of bioactive molecules (R)-tembamide, (S)-tembamide, (S)-moprolol, (S)-toliprolol and (S)-propanolol, were stereoselectively synthesized in preparative scale with 42% to 90% isolated yields, showcasing the practical potential of our developed system in organic synthesis. Finally, the advantage of using KREDs with known sequence was demonstrated by whole-cell catalysis, in which β-nitro alcohol (R)-2k, the key synthetic intermediate of hypoglycemic natural product (R)-tembamide, was produced in a space-time yield of 178 g L?1 d?1 as well as 95% ee by employing the whole cells of a recombinant E. coli strain coexpressing RasADH and glucose dehydrogenase as the biocatalyst.
- Wang, Zexu,Wu, Xiaofan,Li, Zhining,Huang, Zedu,Chen, Fener
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supporting information
p. 3575 - 3580
(2019/04/14)
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- A metalloligand appended with benzimidazole rings: Tetranuclear [CoZn3] and [CoCd3] complexes and their catalytic applications
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A novel Co3+-based metalloligand 1 offering appended benzimidazole rings has been prepared and utilized for the synthesis of tetranuclear [CoZn3] (2 and 2-Cl) and [CoCd3] (3) heterometallic coordination complexes (HCCs). C
- Pandey, Saurabh,Bansal, Deepak,Gupta, Rajeev
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p. 9847 - 9856
(2018/06/18)
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- Organocatalytic Asymmetric Domino Michael/Acyl Transfer Reaction Between α-Nitroketones and in situ-Generated ortho-Quinone Methides: Route to 2-(1-Arylethyl)phenols
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An organocatalytic asymmetric domino Michael/acyl transfer reaction between α-nitroketones and o-quinone methides is disclosed. o-Quinone methides are generated in situ from 2-sulfonylmethylphenols in basic medium. With 10 mol% of bifunctional squaramide catalyst, high yields and excellent enantioselectivities are achieved for a variety of O-acyl 2-(1-arylethyl)phenols under mild reaction condition. (Figure presented.).
- Gharui, Chandan,Behera, Debasmita,Pan, Subhas Chandra
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supporting information
p. 4502 - 4508
(2018/11/10)
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- Organocatalytic Asymmetric Michael/Hemiketalization/Retro-aldol Reaction of α-Nitroketones with Unsaturated Pyrazolones: Synthesis of 3-Acyloxy Pyrazoles
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An organocatalytic asymmetric cascade Michael/hemiketalization/retro-aldol reaction between unsaturated pyrazolones and α-nitroketones is described. A bifunctional thiourea catalyst was found to be efficient for this reaction. With 10 mol % of catalyst, high yields as well as excellent enantioselectivities are attained for a variety of 3-acyloxy pyrazoles under mild reaction conditions.
- Maity, Rajendra,Gharui, Chandan,Sil, Arun K.,Pan, Subhas Chandra
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supporting information
p. 662 - 665
(2017/02/10)
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- Mg-NHC complex on the surface of nanomagnesium oxide for catalytic application
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We have developed a simple and eco-friendly protocol for the synthesis of Mg-NHC complexes. The Mg-NHC complex is prepared by reacting nano-MgO with imidazolium salts. Thus prepared Mg-NHC complex has been realized in two divergent reactions one in C-C bond formation and other in dehydration reaction. Further, the Mg-NHC catalyst has been characterized by SEM, TEM, XPS, Raman Spectroscopy and XRD analysis.
- Shaikh, Melad,Sahu, Mahendra,Gavel, Pramod Kumar,Turpu, Goverdhan Reddy,Khilari, Santimoy,Pradhan, Debabrata,Ranganath, Kalluri V.S.
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- Designing new analogs for streamlining the structure of cytotoxic lamellarin natural products
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Despite the therapeutic potential of marine-derived lamellarin natural products, their preclinical development has been hampered by their lipophilic nature, causing very poor aqueous solubility. In order to develop more drug-like analogs, their structure was streamlined in this study from both the cytotoxic activity and lipophilicity standpoints. First, a modified total synthetic route was successfully devised to construct a library of 59 systematically designed lamellarin analogs, which were then subjected to cytotoxicity and log P determinations. Along with the 25 first-generation lamellarins previously synthesized in our laboratory, the structure-activity and structure-lipophilicity relationships were extensively evaluated. Our results clearly indicated the additional structural requirements around the lamellarin skeleton which, when combined with those reported previously, can provide invaluable guidance for further modifications to increase the aqueous solubility of these compounds.
- Tangdenpaisal, Kassrin,Worayuthakarn, Rattana,Karnkla, Supatra,Ploypradith, Poonsakdi,Intachote, Pakamas,Sengsai, Suchada,Saimanee, Busakorn,Ruchirawat, Somsak,Chittchang, Montakarn
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p. 925 - 937
(2015/03/31)
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- (2S,5R)-2-Methylaminomethyl-1-methyl-5-phenylpyrrolidine, a chiral diamine ligand for copper(ii)-catalysed Henry reactions with superb enantiocontrol
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A cis-2-aminomethyl-5-phenylpyrrolidine, which is easily available from methyl Boc-l-pyroglutamate, was found to be a highly efficient chiral ligand for Cu(ii)-catalysed Henry reactions. Excellent yields (>90%) and superb levels of enantiocontrol (98.5-99.6% ee) were reached with aromatic, heteroaromatic, vinylic, and aliphatic aldehydes (36 examples). This journal is the Partner Organisations 2014.
- Scharnagel, Dagmar,Prause, Felix,Kaldun, Johannes,Haase, Robert G.,Breuning, Matthias
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supporting information
p. 6623 - 6625
(2014/06/10)
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- Probing the evolution of an Ar-BINMOL-derived salen-Co(iii) complex for asymmetric Henry reactions of aromatic aldehydes: Salan-Cu(ii) versus salen-Co(iii) catalysis
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A new type of chiral salen-Co catalyst that features aromatic π-walls and an active Co(iii) center has been developed for enantioselective Henry/nitroaldol reactions on the basis of salen-Cu catalysis. The asymmetric Henry reaction of aromatic aldehydes a
- Wei, Yun-Long,Yang, Ke-Fang,Li, Fei,Zheng, Zhan-Jiang,Xu, Zheng,Xu, Li-Wen
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p. 37859 - 37867
(2014/11/07)
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- Probing the evolution of an Ar-BINMOL-derived salen-Co(iii) complex for asymmetric Henry reactions of aromatic aldehydes: Salan-Cu(ii) versus salen-Co(iii) catalysis
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A new type of chiral salen-Co catalyst that features aromatic π-walls and an active Co(iii) center has been developed for enantioselective Henry/nitroaldol reactions on the basis of salen-Cu catalysis. The asymmetric Henry reaction of aromatic aldehydes a
- Wei, Yun-Long,Yang, Ke-Fang,Li, Fei,Zheng, Zhan-Jiang,Xu, Zheng,Xu, Li-Wen
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p. 37859 - 37867
(2014/12/11)
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- Highly efficient and large-scalable glucoamylase-catalyzed Henry reactions
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Eco-friendly, highly efficient and large-scalable Henry reactions of aromatic aldehydes and nitroalkanes catalyzed by glucoamylase from Aspergillus niger (AnGA) are described. The reactions were carried out at 30 °C in the mixed solvents of ethanol and wa
- Gao, Na,Chen, Yan-Li,He, Yan-Hong,Guan, Zhi
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p. 16850 - 16856
(2013/09/23)
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- Rhodium-catalyzed enantioselective hydrogenation of β-acylamino nitroolefins: A new approach to chiral β-amino nitroalkanes
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An efficient and highly enantioselective catalytic asymmetric hydrogenation of β-acylamino nitroolefins has been realized by using Rh-TangPhos as the catalyst. A series of β-amino nitroalkane products, which are versatile intermediates in organic synthesis, were obtained with high yield and good enantioselectivity.
- Zhou, Ming,Dong, Dejun,Zhu, Baolin,Geng, Huiling,Wang, Yan,Zhang, Xumu
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supporting information
p. 5524 - 5527
(2013/11/19)
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- Highly enantioselective reduction of β-amino nitroolefins with a simple n-sulfinyl urea as bifunctional catalyst
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Simple but effective: A structurally simple N-sulfinyl urea was found to be a highly efficient bifunctional catalyst, which allows for the development of a novel pathway for the construction of chiral β-amino nitroalkanes through enantioselective reduction of β-amino nitroolefins by trichlorosilane. High yields and excellent enantioselectivities were obtained for a broad range of β-arylamino nitroolefin substrates (see scheme). Copyright
- Liu, Xiang-Wei,Yan, Yan,Wang, Yong-Qiang,Wang, Chao,Sun, Jian
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supporting information; experimental part
p. 9204 - 9207
(2012/08/27)
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- Novel amide- and sulfonamide-based aromatic ethanolamines: Effects of various substituents on the inhibition of acid and neutral ceramidases
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In the present study we describe the design and synthesis of a series of amide- and sulfonamide-based compounds as inhibitor of recombinant acid and neutral ceramidases. Inhibition of ceramidases has been shown to induce apoptosis and to increase the efficacy of conventional chemotherapy in several cancer models. B-13, lead in vitro inhibitor of acid ceramidase has been recently shown to be virtually inactive towards lysosomal acid ceramidase in living cells at lower concentrations and for a shorter time of treatment, suggesting the development of more potent inhibitors. In this study, a detailed SAR investigation has been performed to understand the effect of different substituents on the phenyl ring of amide- and sulfonamide-based compounds that partially resemble the structure of well-known inhibitors such as B-13, D-e-MAPP as well as NOE. Our results suggest that the electronic effects of the substituents on phenyl ring in B-13 and D-e-MAPP analogues have negligible effects either in enhancing the inhibition potencies or for selectivity towards aCDase over nCDase. However, the hydrophobicity and the steric effects of longer alkyl chains (n-Pr, n-Bu or t-Bu groups) at the phenyl ring were found to be important for an enhanced selectivity towards aCDase over nCDase.
- Bhabak, Krishna P.,Arenz, Christoph
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p. 6162 - 6170
(2012/11/06)
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- Copper complex of aminoisoborneol schiff base Cu2(SBAIB-d) 2: An efficient catalyst for direct catalytic asymmetric nitroaldol (henry) reaction
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A new bifunctional copper complex of the aminoisoborneol Schiff base - Cu2(SBAIB-d)2 - has been developed for the effective direct catalytic asymmetric Henry reaction. One mol% of this catalyst produces the expected Henry products in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee). The utility of the present catalyst was also extended to the Henry reaction with nitroethane and 1-nitropropane that furnished the corresponding products in moderate to high yields (up to 99%) with moderate to high enantioselectivities of syn (up to 98% ee) and anti (up to 98% ee) diastereomers. The highlights of this catalytic system are easy manipulation, air and moisture tolerance, the need for 1 mol% of an easily synthesizable catalyst and the high enantioselectivities achieved for a wide range of substrates. Copyright
- Boobalan, Ramalingam,Lee, Gene-Hsian,Chen, Chinpiao
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supporting information
p. 2511 - 2520
(2012/11/07)
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- Enzyme-catalyzed Henry (nitroaldol) reaction
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Transglutaminase was first used to catalyze Henry reactions of aliphatic, aromatic and hetero-aromatic aldehydes with nitroalkanes. The reactions were carried out at room temperature, and the corresponding nitro alcohols were obtained in yields up to 96%.
- Tang, Rong-Chang,Guan, Zhi,He, Yan-Hong,Zhu, Wen
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experimental part
p. 62 - 67
(2010/10/04)
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- THIAZOLYL COMPOUNDS USEFUL AS KINASE INHIBITORS
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The invention provides compounds of formula I [INSERT CHEMICAL STRUCTURE HERE] (I) and pharmaceutically acceptable salts thereof. The formula I thiazolyl compounds inhibit tyrosine kinase activity thereby making them useful as anticancer agents and for the treatment of Alzheimer's Disease.
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Page/Page column 23
(2010/03/31)
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- Novel 1H-(benzimidazol-2-yl)-1H-pyridin-2-one inhibitors of insulin-like growth factor I (IGF-1R) kinase
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A novel class of 1H-(benzimidazol-2-yl)-1H-pyridin-2-one inhibitors of insulin-like growth factor I (IGF-1R) kinase is described. This report discusses the SAR of 4-(2-hydroxy-2-phenylethylamino)-substituted pyridones with improved IGF-1R potency.
- Wittman, Mark D.,Balasubramanian, Balu,Stoffan, Karen,Velaparthi, Upender,Liu, Pieying,Krishnanathan, Subramaniam,Carboni, Joan,Li, Aixin,Greer, Ann,Attar, Ricardo,Gottardis, Marco,Chang, Chiehying,Jacobson, Bruce,Sun, Yax,Hansel, Steven,Zoeckler, Mary,Vyas, Dolatrai M.
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p. 974 - 977
(2007/10/03)
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- Nitroaldol-reaction of aldehydes in the presence of non-activated Mg:Al 2:1 hydrotalcite; A possible new mechanism for the formation of 2-aryl-1,3-dinitropropanes
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Commercially available, non-activated 2:1 Mg:Al hydrotalcite catalyzes the nitroaldol reaction between a variety of aromatic and aliphatic aldehydes and simple nitroalkanes such as nitromethane and nitroethane. A new mechanism is proposed for the formation of the 1,3-dinitropropanes. The threo/erythro diastereoselectivity of the nitroethane-adducts was determined by 1H NMR spectroscopy and was found to range from 50:50 to 70:30. The substituents of the aromatic aldehydes influenced the isomer ratio.
- Cwik, Agnieszka,Fuchs, Aliz,Hell, Zoltán,Clacens, Jean-Marc
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p. 4015 - 4021
(2007/10/03)
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- FUNGAL CELL WALL SYNTHESIS GENE
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A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed.Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
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- Facile synthesis of 2-nitroalkanols mediated with LiAlH4 as catalyst
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A variety of aldehydes reacted with nitroalkanes in the presence of catalytic amount of LiAlH4 to give 2-nitroalkanols at 0 °C in excellent yields (82~98%).
- Youn, So Won,Kim, Yong Hae
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p. 880 - 882
(2007/10/03)
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