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Real-time assessment of enantiomeric purity via a polarimetric/absorption detector response function. 通过偏振/吸收检测器响应函数实时评估对映体纯度。
Enantiomer Pub Date : 2002-01-01 DOI: 10.1080/10242430210702
Sean W. Linder, Gary W. Yanik, E. Francotte, D. R. Bobbitt
{"title":"Real-time assessment of enantiomeric purity via a polarimetric/absorption detector response function.","authors":"Sean W. Linder, Gary W. Yanik, E. Francotte, D. R. Bobbitt","doi":"10.1080/10242430210702","DOIUrl":"https://doi.org/10.1080/10242430210702","url":null,"abstract":"The development of methodology appropriate for the rapid and precise assessment of enantiomeric purity is a critical need in the life sciences with impact in a number of areas including biomedical research, biotechnology, and pharmaceutical science. Real-time assessment of enantiomeric purity is critical to decisions related to possible product purity and/or the need for, and the type of additional processing. Recently, we have shown that laser-based polarimetric detection, in combination with ultraviolet detection, can be used to assess enantiomeric purity in real-time as an adjunct to the separation process. A mass-independent response function is obtained from the ratio of the normalized polarimetric signal relative to the normalized UV signal. This response ratio will be shown to be equivalent to the enantiomeric excess and independent of concentration and chromatographic resolution. The methodology will be evaluated as a function of injected mass, enantiomeric excess, chromatographic resolution, and peak asymmetry.","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"7 1","pages":"41-7"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87323529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Concise synthesis and enzymatic resolution of L-(+)-homophenylalanine hydrochloride. L-(+)-同苯丙氨酸盐酸盐的简明合成及酶解。
Enantiomer Pub Date : 2002-01-01 DOI: 10.1080/10242430210706
Hua Zhao, R. G. Luo, D. Wei, S. Malhotra
{"title":"Concise synthesis and enzymatic resolution of L-(+)-homophenylalanine hydrochloride.","authors":"Hua Zhao, R. G. Luo, D. Wei, S. Malhotra","doi":"10.1080/10242430210706","DOIUrl":"https://doi.org/10.1080/10242430210706","url":null,"abstract":"The N-acetyl-homophenylalanine ethyl ester was synthesized by a simple three-step-reaction strategy. L-(+)-homophenylalanine hydrochloride with 98% ee was obtained through a kinetic resolution process using industrial enzyme alcalase. Compared with other methods, this strategy has the advantage of economical and simple procedure giving high product optical purity.","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"6 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82067304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 17
Absolute stereochemistry of chiral C60 fullerene bis-adducts. 手性C60富勒烯双加合物的绝对立体化学。
Enantiomer Pub Date : 2002-01-01 DOI: 10.1080/10242430210704
Kazuhiro Yoshida, S. Ōsawa, K. Monde, Masataka Watanabe, N. Harada
{"title":"Absolute stereochemistry of chiral C60 fullerene bis-adducts.","authors":"Kazuhiro Yoshida, S. Ōsawa, K. Monde, Masataka Watanabe, N. Harada","doi":"10.1080/10242430210704","DOIUrl":"https://doi.org/10.1080/10242430210704","url":null,"abstract":"To determine the absolute configuration of chiral fullerene bis-adducts, we have studied the double Bingel reaction of C60 with chiral tether (2S,3S)-(-)-9 derived from (R,R)-(+)-tartaric acid, and have succeeded in isolating two possible chiral bis-adducts 10a (5%) and 10b (2%) in addition to the Cs-symmetrically added derivative 10c (40%). The CD spectra of chiral bis-adducts [CD(+)281]-10a and [CD(-)281]-10b show very intense Cotton effects, which are almost of mirror image, indicating that their chiral C60 pi-electron systems are enantiomeric each other. The 1H and 13C NMR spectra of 10a and 10b indicate that they have C2-symmetrical structures, and the vicinal coupling constants between two equivalent protons H-2 and H-2' were determined as 1.2 Hz for 10a and 1.8 Hz for 10b, respectively by the 13C satellite band method. From the conformational analyses, the absolute configurations of these chiral C60 fullerene bis-adducts were unambiguously determined as [CD(+)281]-(S,S,fC)-10a and [CD(-)281]-(S,S,fA)-10b, respectively.","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"18 1","pages":"23-32"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79653350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
Enantiopure spiro[3.3]heptane-2,6-dicarboxylic acid. 对映纯螺[3.3]庚烷-2,6-二羧酸。
Enantiomer Pub Date : 2002-01-01 DOI: 10.1080/10242430210705
Hongzhi Tang, H. Miura, Y. Kawakami
{"title":"Enantiopure spiro[3.3]heptane-2,6-dicarboxylic acid.","authors":"Hongzhi Tang, H. Miura, Y. Kawakami","doi":"10.1080/10242430210705","DOIUrl":"https://doi.org/10.1080/10242430210705","url":null,"abstract":"Using chiral HPLC and 13C NMR analyses, the optical purity of (+)-spiro[3.3]heptane-2,6-dicarboxylic acid (1) obtained by the known diastereomer method with brucine was first clarified to be 90% e.e., which was conventionally considered to be 100% e.e. Among the ester derivatives synthesized, dicinnamyl spiro[3.3]heptane-2,6-dicarboxylate (2) was found to show high optical separation ability on the chiral HPLC with cellulose phenyl carbamate stationary phase eluting with hexane/2-propanol (10/1, v/v) at a flow rate of 0.4 ml/min at 35 degrees C (separation factor, a, 1.14), and the isolated optically pure (+)- and (-)-2 show [alpha]D26 of + 1.84 degrees (c = 1.74, CHCl3) and -1.84 degrees (c = 1.74, CHCl3), respectively. Acidic hydrolysis of optically pure (+)-/(-)-2 without racemization yielded optically pure (+)-/(-)-1, exhibiting [phi]405(270 = + 21.1 degrees ([phi]D27 = +9.1 degrees) (c = 5.33, acetone) and [phi]405(27) = -21.1 degrees ([phi]D27 -9.1 degrees) (c = 5.32, acetone), respectively.","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"61 1","pages":"5-9"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80625737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Optical resolution of 5-alkyl-delta-valerolactones and synthesis of optically active 5-fluoroalkanols. 5-烷基-三角戊内酯的光学拆分及光学活性5-氟烷醇的合成。
Enantiomer Pub Date : 2002-01-01 DOI: 10.1080/10242430210707
A. Riswoko, Y. Aoki, T. Hirose, H. Nohira
{"title":"Optical resolution of 5-alkyl-delta-valerolactones and synthesis of optically active 5-fluoroalkanols.","authors":"A. Riswoko, Y. Aoki, T. Hirose, H. Nohira","doi":"10.1080/10242430210707","DOIUrl":"https://doi.org/10.1080/10242430210707","url":null,"abstract":"Optical resolutions of 5-alkyl-delta-valerolactones were carried out by derivatization to the diastereomeric amides, in which (R)-(+)-1-(1-naphthyl)ethylamine or (S)-(-)-1-phenylethylamine were used as resolving agents. Optically active 5-fluoroalkanols, useful intermediates for fluorinated ferroelectric liquid crystals, were derived from the resolved lactones in four steps without racemization.","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"1 1","pages":"33-9"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72879887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Chemical process evolution of efavirenz, a potent non-nucleosidal HIV reverse transcriptase inhibitor. 有效的非核苷类HIV逆转录酶抑制剂依非韦伦的化学过程演化。
Enantiomer Pub Date : 2000-06-13 DOI: 10.1002/CHIN.200024280
C. Chen, L. Tan
{"title":"Chemical process evolution of efavirenz, a potent non-nucleosidal HIV reverse transcriptase inhibitor.","authors":"C. Chen, L. Tan","doi":"10.1002/CHIN.200024280","DOIUrl":"https://doi.org/10.1002/CHIN.200024280","url":null,"abstract":"","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"20 1","pages":"599-608"},"PeriodicalIF":0.0,"publicationDate":"2000-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80879902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
Developing a chiral toolbox for asymmetric catalytic reactions. 开发用于不对称催化反应的手性工具箱。
Enantiomer Pub Date : 2000-05-30 DOI: 10.1002/CHIN.200022284
X. Zhang
{"title":"Developing a chiral toolbox for asymmetric catalytic reactions.","authors":"X. Zhang","doi":"10.1002/CHIN.200022284","DOIUrl":"https://doi.org/10.1002/CHIN.200022284","url":null,"abstract":"During the last several decades, chemists have made major progress in discovering man-made catalysts to perform challenging asymmetric transformations. The research in our group addresses fundamental and practical problems in this field by developing a diverse set of chiral ligands that combine with transition metals to form highly enantioselective catalysts. Families of tridentate ligands have been developed for the enantioselective hydrogenation of unfunctionalized substrates. In addition, we have developed several new bidentate phosphine ligands for asymmetric catalysis. The common feature of these ligands are that they contain rigid aromatic backbones or ring structures which restrict conformational flexibility of the ligands. Several asymmetric reactions have been studied: asymmetric hydrogenation of functionalized substrates such as N-acylaminoacrylic acids, enamides and enol acetates; asymmetric hydrogenation of simple ketones, and imines; and asymmetric carbon-carbon bond forming reactions. In addition, we have designed and synthesized several novel chiral monophosphines for asymmetric catalytic reactions. Transition metal complexes with these monophosphines have also been developed for asymmetric transformations.","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"3 1","pages":"541-55"},"PeriodicalIF":0.0,"publicationDate":"2000-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80761381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 22
Enantioseparation of aminoglutethimide with cyclodextrins in capillary electrophoresis and studies of selector-selectand interactions using NMR spectroscopy and electrospray ionization mass spectrometry. 毛细管电泳环糊精对氨基乙硫胺对映体分离及核磁共振和电喷雾质谱研究选择-选择和相互作用。
Enantiomer Pub Date : 2000-01-01
B Chankvetadze, M Fillet, N Burjanadze, D Bergenthal, C Bergander, H Luftmann, J Crommen, G Blaschke
{"title":"Enantioseparation of aminoglutethimide with cyclodextrins in capillary electrophoresis and studies of selector-selectand interactions using NMR spectroscopy and electrospray ionization mass spectrometry.","authors":"B Chankvetadze,&nbsp;M Fillet,&nbsp;N Burjanadze,&nbsp;D Bergenthal,&nbsp;C Bergander,&nbsp;H Luftmann,&nbsp;J Crommen,&nbsp;G Blaschke","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The enantiomers of aminoglutethimide [2-(p-aminophenyl)-2-ethylglutarimide, AGT] can be resolved in CE using all of three most commonly used native cyclodextrins (CD): alpha-, beta-, and gamma-CDs. The migration order of the enantiomers was opposite using beta-CD compared to alpha- and gamma-CDs as chiral selectors. In order to examine some underlying mechanisms of the chiral recognition the interaction of AGT with the chiral selectors was studied with one- and two-dimensional NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). The Job's and Scott's plots constructed based on the complexation-induced chemical shifts (CICS) observed in NMR spectra provided some preliminary information on the stoichiometry of the intermolecular complexes but did not seem to be absolutely reliable perhaps because the self-association of the analyte molecules and the formation of multiple type selectand-selector complexes. Therefore, an attempt was made to characterize the complexes using ESI-MS. This technique provided information on the stoichiometry and relative affinity constants of selector-selectand complexes. The information on the structure of complexes in the solution was obtained using one-dimensional rotating frame nuclear Overhauser enhancement (1D-ROESY) NMR spectroscopic studies. Significant differences were observed between the structures of the AGT complexes with beta- and gamma-CD.</p>","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"5 3-4","pages":"313-22"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21948755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Synthesis of enantiomerically pure C2-symmetric 4-pyrrolidinopyridine derivative as a chiral acyl transfer catalyst for the kinetic resolution of secondary alcohols 对映体纯c2对称4-吡咯烷二吡啶衍生物手性酰基转移催化剂的合成
Enantiomer Pub Date : 2000-01-01
Naraku, Shimomoto, Hanamoto, Inanaga
{"title":"Synthesis of enantiomerically pure C2-symmetric 4-pyrrolidinopyridine derivative as a chiral acyl transfer catalyst for the kinetic resolution of secondary alcohols","authors":"Naraku,&nbsp;Shimomoto,&nbsp;Hanamoto,&nbsp;Inanaga","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The first chiral C2-symmetric 4-pyrrolidinopyridine (PPY) derivative was synthesized in an enantiomerically pure form and successfully utilized as a chiral nucleophilic catalyst for the kinetic resolution of secondary alcohols leaving one enantiomer with high selectivity factors (up to s = 13.5).</p>","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"5 1","pages":"135-8"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21613592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Lanthanide complexes as smart CD probes for chirality sensing of biological substrates. 镧系配合物作为智能CD探针用于生物底物手性传感。
Enantiomer Pub Date : 2000-01-01
H Tsukube, S Shinoda
{"title":"Lanthanide complexes as smart CD probes for chirality sensing of biological substrates.","authors":"H Tsukube,&nbsp;S Shinoda","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Lanthanide tris(beta-diketonates) and porphyrinates acted as effective circular dichroism (CD) probes for chirality sensing of neutral and zwitterionic guests. They were electrically neutralized but formed highly coordinated 1:1 complexes with various guests. When a chiral, non-chromophoric guest was combined with a chromophoric lanthanide probe, the resulting highly coordinated complex exhibited characteristic CD signal, the sign of which was dependent on the absolute configuration of the bound guest. Since there are wide variations of coordinating ligands and lanthanide centers, lanthanide coordination chemistry offers great possibilities for the design of new CD chirality sensory systems especially for biologically important guests.</p>","PeriodicalId":11752,"journal":{"name":"Enantiomer","volume":"5 1","pages":"13-22"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21613806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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