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Benzyl isobornyl amines: a simple and practical class of NMR discriminating agents for effective chiral recognition of acids 苄基异鸟胺:一类简单实用的核磁共振鉴别剂，用于有效的手性识别酸
Tetrahedron, asymmetry Pub Date : 2017-10-15 Epub Date: 2017-08-23 DOI: 10.1016/j.tetasy.2017.08.007
Jayaraman Kannappan , Aditya N. Khanvilkar , Gourav M. Upadhyay , Ashutosh V. Bedekar
{"title":"Benzyl isobornyl amines: a simple and practical class of NMR discriminating agents for effective chiral recognition of acids","authors":"Jayaraman Kannappan ,&nbsp;Aditya N. Khanvilkar ,&nbsp;Gourav M. Upadhyay ,&nbsp;Ashutosh V. Bedekar","doi":"10.1016/j.tetasy.2017.08.007","DOIUrl":"10.1016/j.tetasy.2017.08.007","url":null,"abstract":"<div><p>The design and synthesis of a few simple <em>N</em>-benzyl derivatives of isobornyl amine is presented. The derivatives have been assessed as chiral solvating agents for effective discrimination of the signals of some acids in NMR analysis. The single crystal X-ray analysis of the salts of (<em>R</em>)-mandelic acid with two of the title derivatives help to understand the supramolecular interactions and assign the induced chemical shifts in <sup>1</sup><span>H NMR analysis. The title derivative is found to be suitable for quantitative determination of the enantiomeric<span> excess of unknown enantiomeric purity as well as being efficient in resolving racemic mandelic acid.</span></span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1297-1303"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.08.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72782324","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: 5
Verification study for an empirical rule in diverse helical conformational behaviors of asymmetric 1,2-diacyl-sn-glycerols in the solution state 不对称1,2-二酰基- sn -甘油溶液中不同螺旋构象行为经验规律的验证研究
Tetrahedron, asymmetry Pub Date : 2017-10-15 Epub Date: 2017-10-23 DOI: 10.1016/j.tetasy.2017.09.021
Yoshihiro Nishida , Yuan Mengfei , Kaito Fujisawa , Sakura Kitagawa , Hirofumi Dohi , Hirotaka Uzawa
{"title":"Verification study for an empirical rule in diverse helical conformational behaviors of asymmetric 1,2-diacyl-sn-glycerols in the solution state","authors":"Yoshihiro Nishida ,&nbsp;Yuan Mengfei ,&nbsp;Kaito Fujisawa ,&nbsp;Sakura Kitagawa ,&nbsp;Hirofumi Dohi ,&nbsp;Hirotaka Uzawa","doi":"10.1016/j.tetasy.2017.09.021","DOIUrl":"10.1016/j.tetasy.2017.09.021","url":null,"abstract":"<div><p><span><span>Cell-membrane glycerophospholipids and </span>glycolipids have a common asymmetric skeleton of 1,2-diacyl-</span><em>sn</em><span>-glycerols. The 1,2-diacyl moiety in solutions permits a rapid equilibrium among three helical conformers, namely gt(+), gg(−), and tg, to display diverse conformational properties. The conformational property changes variably not only by head groups at the </span><em>sn</em><span>-3 position, but also by the solvent conditions applied. Recently, we came across an empirical rule in the conformational diversity in the solution state when we assumed the term of ‘helical disparity’ for the equilibrium between gt(+) and gg(−) conformers with reversed helical signs for each other. The sign and magnitude of the helical disparity (%) governs the (+)- or (−)-chirality around the lipid tail and corresponds to the magnitude of the exciton couplet CD (circular dichroism) bands. The empirical rule expresses that the disparity (%) changes linearly by the function of gt(+) population (%). Herein, the rule was verified by </span><sup>1</sup>H NMR spectroscopy using different types of 1,2-diacyl-<em>sn</em>-glycerols as model compounds. The present paper describes that the rule is formulated with a general equation (Eq-1): ‘helical disparity (%)’ = [gt(+)−gg(−)] (%) = A[gt(+)−B], in which A and B are constants taking values around 1.3 and 38, respectively. This rule is maintained regardless of the 1,2-diacyl and <em>sn</em>-3 substituent groups as far as examined here, while affording several exceptions. With Eq-1 (A = 1.3, B = 38), a conformational diagram can be obtained. This allows us to overview the diverse helical conformational properties of the asymmetric 1,2-diacyl-<em>sn</em>-glycerols in the solutions state.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1435-1443"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.09.021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76294121","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
An enantiopure diselenide based on a chiral bicyclic backbone—synthesis and configuration assignment 一种基于手性双环骨架的对映纯二硒化物-合成和构型分配
Tetrahedron, asymmetry Pub Date : 2017-10-15 Epub Date: 2017-08-30 DOI: 10.1016/j.tetasy.2017.08.008
Karolina Kamińska , Elżbieta Wojaczyńska , Claudio Santi , Luca Sancineto , Marianna Francesca Pensa , Andrzej Kochel , Robert Wieczorek , Jacek Wojaczyński , Gauthier Slupski
{"title":"An enantiopure diselenide based on a chiral bicyclic backbone—synthesis and configuration assignment","authors":"Karolina Kamińska ,&nbsp;Elżbieta Wojaczyńska ,&nbsp;Claudio Santi ,&nbsp;Luca Sancineto ,&nbsp;Marianna Francesca Pensa ,&nbsp;Andrzej Kochel ,&nbsp;Robert Wieczorek ,&nbsp;Jacek Wojaczyński ,&nbsp;Gauthier Slupski","doi":"10.1016/j.tetasy.2017.08.008","DOIUrl":"10.1016/j.tetasy.2017.08.008","url":null,"abstract":"<div><p><span><span>An enantiomerically pure </span>diselenide<span> containing two chiral bicyclic subunits was prepared from the respective halides<span>. The stereochemical outcome of the reaction was established via NMR spectroscopy and X-ray </span></span></span>diffraction measurements.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1367-1372"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.08.008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85849669","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
A closer look on various synthetic routes to Callystatin A: a cytotoxic marine sponge polyketide Callystatin A:一种具有细胞毒性的海绵聚酮
Tetrahedron, asymmetry Pub Date : 2017-09-15 Epub Date: 2017-09-01 DOI: 10.1016/j.tetasy.2017.08.015
Aamer Saeed, Babar Hussain Shah, Rabia Qamar
{"title":"A closer look on various synthetic routes to Callystatin A: a cytotoxic marine sponge polyketide","authors":"Aamer Saeed,&nbsp;Babar Hussain Shah,&nbsp;Rabia Qamar","doi":"10.1016/j.tetasy.2017.08.015","DOIUrl":"10.1016/j.tetasy.2017.08.015","url":null,"abstract":"<div><p><span>Callystatin A<span><span>, a polyketide </span>marine natural product, has been known since 1997 after its isolation from the sponge </span></span><span><em>Callyspongia</em><em> truncata</em></span><span> by Kobayashi et al. It belongs to the leptomcyin family of natural products with a highly conjugated and stereodefined skeleton. The challenging structural topographies and remarkable anti-proliferative properties of (−)-Callystatin A stimulated many researchers to pursue the total synthesis of this marine polyketide. This review is exclusively focused on the research undertaken towards the concise, asymmetric total synthesis of Callystatin A over the last two decades. The various target oriented synthetic pathways are discussed in a chronological order to give a comprehensive overview.</span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 9","pages":"Pages 1095-1126"},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.08.015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89218764","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
Asymmetric synthesis of serinol-monoesters catalyzed by amine transaminases 胺转氨酶催化丝氨酸醇单酯的不对称合成
Tetrahedron, asymmetry Pub Date : 2017-09-15 Epub Date: 2017-08-30 DOI: 10.1016/j.tetasy.2017.08.012
Ingrid C.R. Costa , Rodrigo Octavio M.A. de Souza , Uwe T. Bornscheuer
{"title":"Asymmetric synthesis of serinol-monoesters catalyzed by amine transaminases","authors":"Ingrid C.R. Costa ,&nbsp;Rodrigo Octavio M.A. de Souza ,&nbsp;Uwe T. Bornscheuer","doi":"10.1016/j.tetasy.2017.08.012","DOIUrl":"10.1016/j.tetasy.2017.08.012","url":null,"abstract":"<div><p><span>The asymmetric synthesis<span> of serinol-derivatives was investigated employing different amine transaminases<span><span> as biocatalysts. Under the optimized conditions conversions up to 92% and excellent </span>enantiomeric excesses up to 99% ee were obtained providing access to both, the (</span></span></span><em>R</em>)- and (<em>S</em>)-configurations of the serinol-monoester (2-amino-3-hydroxypropyl hexanoate).</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 9","pages":"Pages 1183-1187"},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.08.012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73869078","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: 5
On the absolute configuration of 1-cyclopropylethan-1-amine 关于1-环丙基比1-胺的绝对构型
Tetrahedron, asymmetry Pub Date : 2017-09-15 Epub Date: 2017-08-29 DOI: 10.1016/j.tetasy.2017.08.005
Matthew W.D. Perry, Anders Eriksson, Marie Rydén Landergren
{"title":"On the absolute configuration of 1-cyclopropylethan-1-amine","authors":"Matthew W.D. Perry,&nbsp;Anders Eriksson,&nbsp;Marie Rydén Landergren","doi":"10.1016/j.tetasy.2017.08.005","DOIUrl":"10.1016/j.tetasy.2017.08.005","url":null,"abstract":"<div><p><span><span>We observed a discrepancy between the reported specific rotation for the enantiomers of 1-cyclopropylethan-1-amine and the values for commercial material. Analyses by </span>VCD of the free amine, by NMR analysis of the derived (</span><em>S</em><span>)-O-methylmandelamides and an X-ray crystal structure of one of the mandelamides defined the specific rotation for each enantiomer.</span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 9","pages":"Pages 1135-1138"},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.08.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79176791","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
Tetrahedron: Asymmetry Reports 四面体:不对称报告
Tetrahedron, asymmetry Pub Date : 2017-09-15 Epub Date: 2017-09-11 DOI: 10.1016/S0957-4166(17)30428-7
{"title":"Tetrahedron: Asymmetry Reports","authors":"","doi":"10.1016/S0957-4166(17)30428-7","DOIUrl":"https://doi.org/10.1016/S0957-4166(17)30428-7","url":null,"abstract":"","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 9","pages":"Pages I-V"},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0957-4166(17)30428-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137428837","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
Cumulative author index 累计作者索引
Tetrahedron, asymmetry Pub Date : 2017-09-15 Epub Date: 2017-09-11 DOI: 10.1016/S0957-4166(17)30429-9
{"title":"Cumulative author index","authors":"","doi":"10.1016/S0957-4166(17)30429-9","DOIUrl":"https://doi.org/10.1016/S0957-4166(17)30429-9","url":null,"abstract":"","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 9","pages":"Pages VI-VIII"},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0957-4166(17)30429-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137428839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A diversity oriented synthesis of d-erythro-sphingosine and siblings d-红鞘氨醇及其兄弟化合物的合成
Tetrahedron, asymmetry Pub Date : 2017-09-15 Epub Date: 2017-08-19 DOI: 10.1016/j.tetasy.2017.08.006
Amrita Ghosh, Shital K. Chattopadhyay
{"title":"A diversity oriented synthesis of d-erythro-sphingosine and siblings","authors":"Amrita Ghosh,&nbsp;Shital K. Chattopadhyay","doi":"10.1016/j.tetasy.2017.08.006","DOIUrl":"10.1016/j.tetasy.2017.08.006","url":null,"abstract":"<div><p><span>An efficient building block-based synthetic protocol has been developed for the synthesis of 3-ketosphingoids with various chain lengths using cross metathesis<span> of a Garner’s aldehyde-derived α,β-unsaturated ketone as the key step. Stereoselective reduction of the biomimetic precursors thus obtained provided </span></span><span>d</span>-<em>erythro</em>-sphingosine and truncated anaogues in good overall yields.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 9","pages":"Pages 1139-1143"},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.08.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72530377","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: 4
Impact of variation of the acyl group on the efficiency and selectivity of the lipase-mediated resolution of 2-phenylalkanols 酰基的变化对脂肪酶介导的2-苯烷醇分离效率和选择性的影响
Tetrahedron, asymmetry Pub Date : 2017-09-15 Epub Date: 2017-08-20 DOI: 10.1016/j.tetasy.2017.08.002
Aoife M. Foley , Declan P. Gavin , Ilona Joniec , Anita R. Maguire
{"title":"Impact of variation of the acyl group on the efficiency and selectivity of the lipase-mediated resolution of 2-phenylalkanols","authors":"Aoife M. Foley ,&nbsp;Declan P. Gavin ,&nbsp;Ilona Joniec ,&nbsp;Anita R. Maguire","doi":"10.1016/j.tetasy.2017.08.002","DOIUrl":"10.1016/j.tetasy.2017.08.002","url":null,"abstract":"<div><p><span>By tuning the steric properties of the acyl group to control the efficiency and selectivity of the resolution, 2-phenyl-1-propanol </span><strong>1a</strong> was prepared by lipase-catalysed hydrolysis using a short-chain acyl group, with <em>E</em>-values of up to 66 (<em>ee</em> up to 95%). 2-Phenylbutan-1-ol <strong>1b</strong> was similarly resolved (up to 86% <em>ee</em>) using the optimised conditions, while the ester of the more sterically demanding 3-methyl-2-phenylbutan-1-ol <strong>1c</strong><span> proved resistant to enzymatic hydrolysis under these conditions.</span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 9","pages":"Pages 1144-1153"},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.08.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76435704","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: 5
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