P. Szcześniak, O. Staszewska-Krajewska, B. Furman, J. Młynarski
{"title":"Solid supported Hayashi–Jørgensen catalyst as an efficient and recyclable organocatalyst for asymmetric Michael addition reactions","authors":"P. Szcześniak, O. Staszewska-Krajewska, B. Furman, J. Młynarski","doi":"10.1016/J.TETASY.2017.10.016","DOIUrl":"https://doi.org/10.1016/J.TETASY.2017.10.016","url":null,"abstract":"","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80520585","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}
J. Žůrek, E. Svobodová, J. Šturala, H. Dvořáková, J. Svoboda, R. Cibulka
{"title":"Chiral ethylene-bridged flavinium salts: the stereoselectivity of flavin-10a-hydroperoxide formation and the effect of substitution on the photochemical properties","authors":"J. Žůrek, E. Svobodová, J. Šturala, H. Dvořáková, J. Svoboda, R. Cibulka","doi":"10.1016/J.TETASY.2017.10.029","DOIUrl":"https://doi.org/10.1016/J.TETASY.2017.10.029","url":null,"abstract":"","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87071173","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}
Ihor Kleban , Andriy V. Tymtsunik , Yuliya V. Rassukana , Oleksandr O. Grygorenko
{"title":"O-(α-Phenylethyl)hydroxylamine as a ‘chiral ammonia equivalent’: synthesis and resolution of 5-oxopyrrolidine- and 6-oxopiperidine-3-carboxylic acids","authors":"Ihor Kleban , Andriy V. Tymtsunik , Yuliya V. Rassukana , Oleksandr O. Grygorenko","doi":"10.1016/j.tetasy.2017.10.027","DOIUrl":"https://doi.org/10.1016/j.tetasy.2017.10.027","url":null,"abstract":"<div><p>An approach to the synthesis and resolution of five- and six-membered lactams (i.e., 5-oxopyrrolidine- and 6-oxopiperidine-3-carboxylic acids) is described. The method relies on the one-pot Michael reaction—cyclization of itaconic acid or diethyl homoitaconate and enantiopure <em>O</em>-(α-phenylethyl)hydroxylamine as a ‘chiral ammonia equivalent’. It is shown that this chiral auxiliary can be used for the separation of diastereomeric lactam products and then easily removed by catalytic hydrogenolysis.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.10.027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91631061","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}
S. Quintana, Maria A. García, M. Marina, R. Gómez, F. J. Mata, P. Ortega
{"title":"Synthesis of chiral carbosilane dendrimers with l-cysteine and N-acetyl-l-cysteine on their surface and their application as chiral selectors for enantiomer separation by capillary electrophoresis","authors":"S. Quintana, Maria A. García, M. Marina, R. Gómez, F. J. Mata, P. Ortega","doi":"10.1016/J.TETASY.2017.10.028","DOIUrl":"https://doi.org/10.1016/J.TETASY.2017.10.028","url":null,"abstract":"","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90049948","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}
Nermin Meriç, Cezmi Kayan, N. Gürbüz, M. Karakaplan, N. E. Binbay, M. Aydemir
{"title":"New functional chiral P-based ligands and application in ruthenium-catalyzed enantioselective transfer hydrogenation of ketones","authors":"Nermin Meriç, Cezmi Kayan, N. Gürbüz, M. Karakaplan, N. E. Binbay, M. Aydemir","doi":"10.1016/J.TETASY.2017.10.004","DOIUrl":"https://doi.org/10.1016/J.TETASY.2017.10.004","url":null,"abstract":"","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83577564","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}
{"title":"Asymmetric aminocarbonylation of iodoalkenes in the presence of α-phenylethylamine as an N-nucleophile","authors":"Gábor Mikle, B. Boros, L. Kollár","doi":"10.1016/J.TETASY.2017.10.012","DOIUrl":"https://doi.org/10.1016/J.TETASY.2017.10.012","url":null,"abstract":"","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76925922","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}
Maria Annunziata M. Capozzi , Cosimo Cardellicchio
{"title":"Stereoselection in the Betti reaction of valine methyl esters","authors":"Maria Annunziata M. Capozzi , Cosimo Cardellicchio","doi":"10.1016/j.tetasy.2017.10.026","DOIUrl":"https://doi.org/10.1016/j.tetasy.2017.10.026","url":null,"abstract":"<div><p><span>The multi-component Betti reaction of 2-naphthol, benzaldehyde and (</span><em>S</em>)-amines, that usually provides highly valuable aminobenzylnaphthol bearing two stereogenic centers, yielded a completely racemic product, when (<em>S</em><span>)-valine methyl ester<span> was employed as the amine in the usual reaction protocol. The cause of this drawback, that appears to be overlooked in the literature, was investigated. As a result, new reaction conditions were set up, that were able to yield the expected useful product, having two fully resolved stereogenic centers. Furthermore, when the effect of substituents on the phenyl ring was preliminarily studied, we found that 4-fluoro- and 4-chlorobenzaldeyde gave stereoisomerically pure compounds also in the original reaction protocol.</span></span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.10.026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91631064","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}
{"title":"Asymmetric aminocarbonylation of iodoalkenes in the presence of α-phenylethylamine as an N-nucleophile","authors":"Gábor Mikle , Borbála Boros , László Kollár","doi":"10.1016/j.tetasy.2017.10.012","DOIUrl":"https://doi.org/10.1016/j.tetasy.2017.10.012","url":null,"abstract":"<div><p>Iodoalkenes, such as 2-iodo-bornene, 17-iodoandrost-16-ene, 3-methoxy-17-iodoestra-1,3,5(10),16-ene, 3β-hydroxy-20-iodopregna-5,20-diene and 3β-hydroxy-12-iodo-5α,25<em>R</em><span>-spirost-11-ene were aminocarbonylated with enantiomerically pure and racemic α-phenylethylamine as the </span><em>N</em><span>-nucleophile in the presence of palladium(0) catalysts. Monodentate and bidentate (chiral and achiral) phosphines<span><span> were used as ligands in the catalytic system. All diastereoisomers of the corresponding carboxamides were characterised as pure stereoisomers using both α-phenylethylamine and iodoalkene in enantiomerically pure form. The diastereoisomers were obtained in moderate to high yields in a </span>chemoselective reaction, </span></span><em>i.e</em><span><span>., carboxamides due to single carbon monoxide insertion were formed exclusively, with no double CO insertion leading to 2-ketocarboxamides. </span>Diastereoselectivities<span> of the aminocarbonylation were investigated using the </span></span><em>N</em>-nucleophile in racemic form by the systematic variation of the catalyst.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.10.012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91631159","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}
{"title":"Chiral enantiopure organosilane precursors for the synthesis of periodic mesoporous organosilicas","authors":"Orit Cohen, Raed Abu-Reziq, Dmitri Gelman","doi":"10.1016/j.tetasy.2017.10.032","DOIUrl":"https://doi.org/10.1016/j.tetasy.2017.10.032","url":null,"abstract":"<div><p><span><span><span><span><span>The manuscript describes synthesis of new chiral organosilica networks starting from modified readily available enantiopure substances such as sugars and </span>amino acids. We report on the successful preparation of robust all-chiral organosilicas by polymerization of the homochiral </span>monomers<span>. When the homochiral organosilane monomers were polymerized in mixtures of polar organic solvents<span> and water in the presence of hydrochloric acid<span> or tetrabutylammonium fluoride as catalysts, mainly spherical </span></span></span></span>microparticles were obtained due to </span>emulsification<span><span> of the hydrophobic monomers in these mixtures. Polycondensation of the chiral organosilanes in the presence of </span>Pluronic<span> P123 as a template produced ordered mesoporous networks. The new all-chiral materials were characterized by SEM, </span></span></span>STEM<span>, BET, SAXS, IR, NMR and TGA.</span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.10.032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90001200","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}