Halide Sedef Karaman , Hamdullah Kılıç , Engin Şahin
{"title":"Asymmetric epoxidation of enones using cumyl hydroperoxide and in situ generated zinc complexes of chiral pyrrolidinyl alcohols","authors":"Halide Sedef Karaman , Hamdullah Kılıç , Engin Şahin","doi":"10.1016/j.tetasy.2017.09.004","DOIUrl":"10.1016/j.tetasy.2017.09.004","url":null,"abstract":"<div><p><span>The homogeneous asymmetric epoxidation of a range of </span>enones<span><span><span> was carried out using cumyl hydroperoxide, </span>diethylzinc<span>, and chiral pyrrolidinyl alcohol-containing ligands to afford the corresponding epoxy ketones<span> with enantioselectivities<span> of ≤97% ee. Examination of the enantioselectivities obtained in the asymmetric epoxidation of enones using a range of chiral ligands indicated that synergy between the sterically bulky bicyclo[2.2.2]octane skeleton and the substituents attached to the carbinol moiety played an important role in determining the reaction enantioselectivity. The position and nature of the substituent on the </span></span></span></span>aromatic ring of the enone also had a pronounced effect on the observed enantioselectivity.</span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 11","pages":"Pages 1626-1632"},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.09.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77660504","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}
Tetsuya Ezawa, Yuya Kawashima, Takuya Noguchi, Seunghee Jung, N. Imai
{"title":"Amidation of carboxylic acids via the mixed carbonic carboxylic anhydrides and its application to synthesis of antidepressant (1 S ,2 R )-tranylcypromine","authors":"Tetsuya Ezawa, Yuya Kawashima, Takuya Noguchi, Seunghee Jung, N. Imai","doi":"10.1016/J.TETASY.2017.10.015","DOIUrl":"https://doi.org/10.1016/J.TETASY.2017.10.015","url":null,"abstract":"","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"73 1","pages":"1690-1699"},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86391837","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}
Alfonso G. Rubia , Mateo M. Salgado , Carlos T. Nieto , Alejandro Manchado , David Díez , Francisca Sanz , Narciso M. Garrido
{"title":"Asymmetric synthesis of tert-butyl ((1R,4aR,8R,8aR)-1-hydroxyoctahydro-1H-isochromen-8-yl)carbamate","authors":"Alfonso G. Rubia , Mateo M. Salgado , Carlos T. Nieto , Alejandro Manchado , David Díez , Francisca Sanz , Narciso M. Garrido","doi":"10.1016/j.tetasy.2017.10.005","DOIUrl":"10.1016/j.tetasy.2017.10.005","url":null,"abstract":"<div><p><span>The asymmetric synthesis of methyl (</span><em>E</em>)-4-((1<em>R</em>,2<em>S</em>,3<em>R</em>)-3-amino-2-((<em>E</em>)-2-methoxycarbonyl-eten-1-yl)cyclohexyl)but-2-enoate <strong>14</strong> has been achieved from dimethyl (2<em>E</em>,7<em>E</em>)-nona-2,7-dienedioate <strong>2</strong>. A key step is the asymmetric synthesis of 1-hydroxyoctahydro-1<em>H</em>-isochromene derivative <strong>5</strong><span><span> whose X-ray analysis corroborated the stereochemistry of the new stereocenters. The asymmetric synthesis of the isochromenyl </span>acetate derivative </span><strong>11</strong> shows the potential of this methodology for fused cyclohexanic system heterocyclic synthesis.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1394-1400"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.10.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81533445","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}
Şafak Özhan Kocakaya , Mehmet Karakaplan , Rosario Scopelliti
{"title":"Synthesis and crystal structure of a chiral lactam and three amino alcohols as potential protein tyrosine phosphates 1B inhibitors","authors":"Şafak Özhan Kocakaya , Mehmet Karakaplan , Rosario Scopelliti","doi":"10.1016/j.tetasy.2017.09.014","DOIUrl":"10.1016/j.tetasy.2017.09.014","url":null,"abstract":"<div><p><span>Chiral lactam </span><strong>2</strong> and three chiral β-amino alcohols <strong>3</strong>–<strong>5</strong><span> have been synthesized and characterized by spectroscopic techniques. Regioselective ring opening reaction of chiral styrene oxide<span> by an amine nucleophile was confirmed by X-ray diffraction data. Ligand </span></span><strong>2</strong>–<strong>4</strong><span> crystallizes in the tetragonal, orthorhombic and tetragonal crystal lattice system respectively. Ligands </span><strong>2</strong>–<strong>6</strong><span> have been used as potential inhibitors for protein tyrosine phosphatase 1B<span> enzyme (PTP1B). The potential inhibitor effect of these molecules to the target protein was investigated by Dock and molecular dynamics calculations. Dock score analysis and Lipinski parameters suggested that ligands </span></span><strong>1</strong>, <strong>2</strong>, <strong>4</strong>–<strong>6</strong><span> are potential inhibitors towards PTP1B, thus indicating that the residues Arg24, Arg254 and Met258, Asp29 in the second active site of PTP1B are essential for the high selectivity of inhibitors. The results indicate that the polar hydrogen bonding<span> interacts with Asp29, Gln102, and the amino acid residues of PTP1B are responsible for governing inhibitory potency of ligands </span></span><strong>1</strong>–<strong>6</strong>.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1342-1349"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.09.014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90604643","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}
Małgorzata Petryk , Agnieszka Janiak , Marcin Kwit
{"title":"‘Double chiral’ new members of calixsalen family","authors":"Małgorzata Petryk , Agnieszka Janiak , Marcin Kwit","doi":"10.1016/j.tetasy.2017.08.021","DOIUrl":"10.1016/j.tetasy.2017.08.021","url":null,"abstract":"<div><p><span><span>Synthesis and X-ray diffraction studies on the first examples of ‘double chiral’ calixsalens are presented. In these molecules, one can clearly distinguish two chiral zones. The first one is made by the macrocycle<span> base, whereas the second chiral zone is set up of the additional chirality elements in the tail of the molecule. The ‘double chiral’ calixsalens are formed through </span></span>cyclocondensation between chiral vicinal diamine of </span><em>trans</em><span><span>-1,2-diaminocyclohexane type and chiral C-5 substituted 2-hydroxyisophthalaldehyde derivatives. The absolute configuration<span> of the dialdehyde did not affect the yield of the macrocyclization reaction. The presence of </span></span>secondary amides<span> in the tail part of the macrocycle leads to formation of hydrogen bonding network in the solid state, while sterical hindrance preserve interdigitation, thus, ‘double chiral’ calixsalens do not form aggregates typical for other calixsalens.</span></span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1373-1383"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.08.021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84677130","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}
Ferenc Miklós , Kristóf Bozó , Zsolt Galla , Matti Haukka , Ferenc Fülöp
{"title":"Traceless chirality transfer from a norbornene β-amino acid to pyrimido[2,1-a]isoindole enantiomers","authors":"Ferenc Miklós , Kristóf Bozó , Zsolt Galla , Matti Haukka , Ferenc Fülöp","doi":"10.1016/j.tetasy.2017.07.006","DOIUrl":"10.1016/j.tetasy.2017.07.006","url":null,"abstract":"<div><p><span>The synthesis of two enantiomeric pairs of pyrimidoisoindoles </span><strong>9a</strong>, <strong>9b</strong> and <strong>10a</strong>, <span>10b</span><span> is reported. During a domino ring-closure reaction, followed by cycloreversion<span>, the chirality of </span></span><em>diendo</em>-(−)-(1<em>R</em>,2<em>S</em>,3<em>R</em>,4<em>S</em>)-3-aminobicyclo[2.2.1]hept-5-ene-2-carboxamide [(−)-<strong>1</strong>] was successfully transfered to heterocycles (+)-<strong>9a</strong>, (+)-<strong>10a</strong>, (−)-<strong>9b</strong>, (−)-<strong>10b</strong> and (−)-<strong>10c</strong>.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1401-1406"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.07.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77936701","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":"A versatile ternary ion pair complex of 2′-amino-1,1′-binaphthalen-2-ol for sensing enantiomers and assignment of absolute configuration","authors":"Anamalagundam Lakshmipriya , Gaonkar Sumana , Nagaraja Rao Suryaprakash","doi":"10.1016/j.tetasy.2017.09.016","DOIUrl":"10.1016/j.tetasy.2017.09.016","url":null,"abstract":"<div><p><span>2′-Amino-1,1′-binaphthalen-2-ol (NOBIN) serves as a versatile chiral solvating agent (CSA) in the presence of trifluoromethanesulfonic acid (TFMS). The formation of a ternary complex has been established by NMR, UV–Vis, fluorescence and IR studies. The mechanism of interactions among the three components in the ternary complex has been proposed and the ternary complex structures of different </span>diastereomers<span> have been established by DFT based theoretical calculations. The present protocol has its ubiquity not only in the analysis of the enantiomeric<span> composition<span> of molecules possessing diverse functionalities, but also in determining the stereospecific assignment of hydroxy acids.</span></span></span></p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1290-1296"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.09.016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75523265","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}
Vaibhav N. Khose, Marina E. John, Anita D. Pandey, Anil V. Karnik
{"title":"Chiral benzimidazoles and their applications in stereodiscrimination processes","authors":"Vaibhav N. Khose, Marina E. John, Anita D. Pandey, Anil V. Karnik","doi":"10.1016/j.tetasy.2017.09.001","DOIUrl":"10.1016/j.tetasy.2017.09.001","url":null,"abstract":"<div><p>Chiral aspects of benzimidazoles have been over-shadowed for a long time due to the large number of reports on benzimidazoles in the medical field in numerous categories of therapeutic agents. The vigorous research activity in chiral applications of benzimidazole derivatives started after bifunctional benzimidazoles made their appearance especially in the last 2–3 decades. Thus, chiral benzimidazoles form a comparatively young branch of chiral chemistry. The presence of pyridine and pyrrole type of nitrogens along with the fused benzene ring confer on this class of molecules, special properties including useful nucleophilicity, hydrogen bonding ability and a rigid backbone, all of which play decisive roles in proven chiral applications. The present review aims to cover the synthetic routes to access chiral benzimidazoles and their applications in a plethora of chiral fields including enantioselective organocatalysis, metal-based catalysis, asymmetric transformations involving benzimidazole-<em>N</em>-heterocyclic carbenes, kinetic resolution, benzimidazole-based macrocyclic hosts in chiral supramolecular chemistry and other miscellaneous chiral applications.</p></div>","PeriodicalId":22237,"journal":{"name":"Tetrahedron, asymmetry","volume":"28 10","pages":"Pages 1233-1289"},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tetasy.2017.09.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81933790","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}