Academic literature on the topic 'Cyclopropanol chiral'
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Journal articles on the topic "Cyclopropanol chiral"
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Kim, Taejin, Amude M. Kassim, Ajit Botejue, Chen Zhang, Jared Forte, David Rozzell, Mark A. Huffman, Paul N. Devine, and John A. McIntosh. "Hemoprotein‐Catalyzed Cyclopropanation En Route to the Chiral Cyclopropanol Fragment of Grazoprevir." ChemBioChem 20, no. 9 (March 6, 2019): 1129–32. http://dx.doi.org/10.1002/cbic.201800652.
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Csuk, René, and Anja Kern. "Synthesis of Rigid Cyclopropanoid Nucleoside Analogues." Zeitschrift für Naturforschung B 57, no. 10 (October 1, 2002): 1169–73. http://dx.doi.org/10.1515/znb-2002-1015.
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A convenient synthesis has been developed for the synthesis of cyclopropanoid nucleoside analogues that possess no additional spacer groups between the heterocycle and the hydroxylated cyclopropane ring. For some of these compounds the respective enantiomers could be separated on an analytical scale by means of HPLC using chiral phases.
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Csuk, René, and Gisela Thiede. "Synthesis of Spacered Nucleoside Analogues Comprising a Difluorocyclopropane Moiety." Zeitschrift für Naturforschung B 58, no. 9 (September 1, 2003): 853–60. http://dx.doi.org/10.1515/znb-2003-0907.
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A novel class of difluorinated cyclopropanoic nucleoside analogues containing a propyl spacer between the cyclopropane ring and the heterocycle has been prepared. Some of these compounds showed weak antitumor activity in prelimary screenings. The resolution of these racemic compounds on an analytical scale was performed by HPLC using chiral stationary phases.
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Ramnauth, Jailall, and Edward Lee-Ruff. "Photodecarbonylation of chiral cyclobutanones." Canadian Journal of Chemistry 75, no. 5 (May 1, 1997): 518–22. http://dx.doi.org/10.1139/v97-060.
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Triplet photosensitized irradiation of 2(S),3(R)-bis[(benzoyloxy)methyl]cyclobutanone gave optically pure (−)E-1(S),2(S)-bis(benzoyloxymethyl)cyclopropane as a major product in the nonpolar fraction along with its stereoisomer and cycloelimination products. The absolute stereochemistry of the chiral cyclopropane was established by independent synthesis and X-ray crystal structure determination of a synthetic precursor. The distribution of decarbonylation and cycloelimination products was inversely dependent on the concentration of the substrate. Irradiation of the same ketone in tetrahydrofuran or benzene gave mostly cycloelimination products. Addition of Michler's ketone increased the ratio of photodecarbonylation, suggesting a triplet state pathway for this process. This was corroborated by the addition of dicyanoethylene, which showed significant quenching of photodecarbonylation. Irradiation of 2(S)-[(benzoyloxy)methyl]cyclobutane in acetone gave the corresponding cyclopropane as the principal product. Keywords: photodecarbonylation, chiral cyclopropanes, cyclobutanones, triplet sensitization.
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Bassan, Ephraim M., Carl A. Baxter, Gregory L. Beutner, Khateeta M. Emerson, Fred J. Fleitz, Simon Johnson, Stephen Keen, et al. "Multikilogram-Scale Synthesis of a Chiral Cyclopropanol and an Investigation of the Safe Use of Lithium Acetylide–Ethylene Diamine Complex." Organic Process Research & Development 16, no. 1 (December 7, 2011): 87–95. http://dx.doi.org/10.1021/op2002497.
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Altamore, Timothy M., Oanh T. K. Nguyen, Quentin I. Churches, Kate Cavanagh, Xuan T. T. Nguyen, Sandhya A. M. Duggan, Guy Y. Krippner, and Peter J. Duggan. "Concise Synthesis of Enantiomerically Pure (1'S,2'R)- and (1'R,2'S)-2S-Amino-3-(2'-aminomethyl-cyclopropyl)propionic Acid: Two E-Diastereoisomers of 4,5-Methano-L-lysine." Australian Journal of Chemistry 66, no. 9 (2013): 1105. http://dx.doi.org/10.1071/ch13309.
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A concise synthesis of both E-isomers of 2S-amino-3-(2′-aminomethyl-cyclopropyl)propionic acid, new methano-l-lysines, is described. The synthetic route includes nine steps from l-methionine, with a key step involving the cyclopropanation of an intermediate E-allylic alcohol. The resultant hydroxymethylcyclopropanes were readily separated and converted into the title α-amino acids. The stereochemistry around the cyclopropane rings was deduced by conducting the cyclopropanation in the presence of N,N,N′,N′-tetramethyl-d-tartaric acid diamide butylboronate, a chiral controller which is known to favour the production of S-hydroxymethyl cyclopropanes from allylic alcohols.
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Barysevich, Maryia V., Volha V. Kazlova, Aliaksandr G. Kukel, Aliaksandra I. Liubina, Alaksiej L. Hurski, Vladimir N. Zhabinskii, and Vladimir A. Khripach. "Stereoselective synthesis of α-methyl and α-alkyl ketones from esters and alkenesviacyclopropanol intermediates." Chemical Communications 54, no. 22 (2018): 2800–2803. http://dx.doi.org/10.1039/c8cc00888d.
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Shen, Yue, Peng-Fei Yang, Gaosheng Yang, Wen-Long Chen, and Zhuo Chai. "Lewis acid-catalyzed enantiospecific [3 + 2] annulations of γ-butyrolactone fused cyclopropanes with aromatic aldehydes: synthesis of chiral furanolignans." Organic & Biomolecular Chemistry 16, no. 15 (2018): 2688–96. http://dx.doi.org/10.1039/c8ob00455b.
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Xie, Ming-Sheng, Yong Wang, Jian-Ping Li, Cong Du, Yan-Yan Zhang, Er-Jun Hao, Yi-Ming Zhang, Gui-Rong Qu, and Hai-Ming Guo. "A straightforward entry to chiral carbocyclic nucleoside analogues via the enantioselective [3+2] cycloaddition of α-nucleobase substituted acrylates." Chemical Communications 51, no. 62 (2015): 12451–54. http://dx.doi.org/10.1039/c5cc04832j.
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Delion, Laëtitia, Thomas Poisson, Philippe Jubault, Xavier Pannecoucke, and André B. Charette. "Synthesis of fluorocyclopropanes via the enantioselective cyclopropanation of fluoro-substituted allylic alcohols using zinc carbenoids." Canadian Journal of Chemistry 98, no. 9 (September 2020): 516–23. http://dx.doi.org/10.1139/cjc-2020-0036.
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Cyclopropanation reactions using zinc carbenoids are a powerful means to access cyclopropanes. Described herein is an enantioselective version of the reaction using zinc reagents and a chiral dioxaborolane ligand in the generation of fluorocyclopropanes. Readily available 2- and 3-fluoroallylic alcohols were efficiently cyclopropanated in high yields and excellent enantioselectivities. This method provides access to a variety of structurally diverse chiral fluorocyclopropanes that can be used as useful chiral building blocks.
Dissertations / Theses on the topic "Cyclopropanol chiral"
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Karkour, Belkacem. "Les cyclopropanols chiraux et leur potentialité synthétique." Paris 11, 1987. http://www.theses.fr/1987PA112378.
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Cette thèse décrit une voie d'accès aux cyclopropanols chiraux et en étudie les potentialités synthétiques. Préparé à partir du méthyl-2 succinate de n-butyle, l'hydroxy-1 méthyl-2 cyclopropanecarboxaldéhyde est un précurseur de (vinylcarbinol)-1 cyclopropanols lesquels, subissent en milieu acide soit une extension de cycle C3→C4 régiospécifique en vinyl-2 cyclobutanones (BF3-Et20), soit une extension de cycle C3→C4→C5 en cyclopentène-2 ones (CH3S03H-P205). La réaction thermique des méthyl-2 vinylcyclopropanes donne par ène-réaction des produits d'ouverture de cycle limitant l'intérêt du réarrangement vinylcyclopropane-cyclopentène ; ce problème est contourné par cette nouvelle approche. Les (R)(+) et (S)(-) méthyl-2 succinates de méthyle, préparés par résolution enzymatique à l'aide de la lipase du pancréas de porc, sont cyclisés par réaction du type acyloïne en (R) et (S) méthyl-3 disiloxycyclobutènes respectivement. Ceux-ci par régression de cycle stéréosélective C4 → C3 en milieu basique, donnent accès sans altération du centre chiral à des hydroxy-1 cyclopropanecarbo xaldéhydes, utilisés pour préparer des (vinylcarbinol)-1 cyclopropanols optiquement actifs. Une extension de cycle C3→C4 régio- et stéréospécifique conduit alors aux vinyl-2 cyclobutanones avec une très bonne énantiosélectivité. Ces composés ont été utilisés pour préparer la (S)(+) méthyl-5 cyclohexène-2-one et un buténolide : la quercus lactone b. Les vinyl-2 cyclobutanones sont des précurseurs de cycle en C5, C6 et C8, cette méthodologie, ne mettant pas en jeu d'ions cyclopropylcarbinyl vrais comme le prouve la stéréospécificité des réarrangements, permet donc, à partir de succinates chiraux, d'envisager la synthèse totale de produits naturels de structures variéesThe aim of this thesis is the preparation and study of the synthetic potential of chiral cyclopropanols. The 1-hydroxy 2-methyl cyclopropanecarboxaldehyde available from 2-methylsuccinate, is used to prepare 1-(vinylcarbinol} cyclopropanols which, undergo acid induced C3 C4 regiospecific ring expansion into 2-vinyl cyclobutanones (BF3-Et20) or C3 -+ C4 --+- C5 ring expansion into cyclopenten-2- ones (CH3S03H-P205). The thermal rearrangement of 2-methyl vinylcyclopropanes leads by an ene-reaction to ring-opened products ; therefore the limitation of the thermal vinylcyclopropane-cyclopentene ring enlargement is removed by this new approach. (R)(+) and (S)(-). Dimethyl 2-methylsuccinates, now available from enantiose lective hydrolysis by porcine pancreatic lipase, undergo acyloin type cyclization into (R) and (S) 3-methyl-1,2-disiloxycyclobutene, respectively. Base-induced stereoselective C4 C3 ring contraction of these cyclobutenes provides 1-hydroxycyclopropanecarboxaldehydes which are used to prepare optically active 1-alkenylcyclopropanols. Then, acid-induced regio- and stereospecific C3---+ C4 ring enlargement leads to 2-vinylcyclobutanones with high enantiomeric excesses. These compounds are used to synthetize (S) 5-methyl cyclohexen-2-one and abutenolide ; i. E. The quercus lactone b2-Vinylcyclobutanones are efficient precursors of 5-, 6- and 8-membered rings. Therefore, this new methodology, which does not involve cyclopropylcarbiny1 cations as proven by the stereospecificity of the rearrangements, allows one to prepare from chiral succinates natural compounds bearing different frameworks
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Ivashkin, Pavel. "Synthesis of original fluorinated cyclopropylcarboxylates." Phd thesis, INSA de Rouen, 2013. http://tel.archives-ouvertes.fr/tel-00924650.
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Organofluorine compounds constitute a large part of all the drugs, crop protection agents and advanced materials produced nowadays. Therefore, there is a great interest in developing the new methods of synthesis of organofluorine compounds. In this thesis we report a novel method of synthesis of monofluorinated cyclopropanes based on the Michael-initiating ring closure (MIRC) reaction. Our method allows obtaining polysubstituted monofluorinated cyclopropanes from ethyl dibromofluoroacetate and various Michael acceptors. We have also implemented the asymetric version of cyclopropanation using a novel oxazolodinone-derived chiral fluorinated reagent. In the final part of this thesis we report the synthesis of a fluorinated analog of L-FAP4, a potent agonist of group II metabotropic glutamate receptors (mGluR II). Incorporation of a fluorine atom is expected to increase the biological activity and bioavailabiblity of this compound.
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El, Abdioui Khalid. "Synthèse d'aminoacides d'intérêt biologique. Cyclopropanation de déhydroaminoesters par catalyse achirale et chirale." Montpellier 2, 1994. http://www.theses.fr/1994MON20105.
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Le but de ce travail est la preparation d'alpha-aminoacides cyclopropaniques par addition de carbenoides, formes a partir de diazoacetates d'alkyle et de complexes de cuivre, sur des dehydro aminoesters n-proteges et d'explorer deux voies possibles d'induction asymetrique, soit par un substrat chiral, soit par catalyse chirale. Dans une partie bibliographique, nous presentons les methodes de synthese asymetrique de ces composes et les types de complexes chiraux des metaux de transition utilisables comme catalyseurs. Cette reaction de cyclopropanation realisee avec les catalyseurs que nous avons prepares dont un nouveau, conduit aux composes souhaites avec de bons rendements. Si l'emploi de catalyseurs chiraux n'a pas donne de reaction de cyclopropanation asymetrique, par contre un resultat encourageant a ete obtenu avec la presence dans le substrat d'un inducteur chiral, la 2-hydroxypinan-3-one
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Pérollier, Céline. "Synthèse de nouvelles métalloporhyrines chirales à substituants cyclopropaniques : applications en catalyse d'époxydation asymétrique et en reconnaissance moléculaire d'enantiomères." Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10191.
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Le biocartol ou acide (1r)-cis-hemicaronaldehydique, un compose cyclopropanique enantiopur provenant de la synthese industrielle d'insecticides pyrethroides, est utilise comme synthon pour la preparation de nouvelles porphyrines chirales. Nous decrivons la synthese d'amides du biocartol, puis la synthese des porphyrines correspondantes par condensation avec le pyrrole. Celles-ci sont obtenues exclusivement sous la forme de l'atropoisomere , avec un rendement variant de 7 a 60%. Une serie de complexes de manganese (iii) de ces chiroporphyrines, derivees d'amides et d'esters du biocartol, ont ete prepares. Ces complexes sont de bons catalyseurs pour l'epoxydation asymetrique d'olefines prochirales. Les substrats a structure rigide cyclique sont epoxydes avec la plus grande selectivite. Ainsi, des exces enantiometriques allant jusqu'a 86% ont ete obtenus pour l'epoxydation du 1,2-dihydronaphtalene en (1s, 2r)-epoxy-1,2,3,4-tetrahydronaphtalene. L'influence de differents facteurs (nature des substituants, solvant, ligand axial, metal) sur la reactivite et l'enantioselectivite ont ete etudies. Des etudes structurales par resonance magnetique nucleaire et par diffraction des rayons x ont permis d'etablir une correlation entre structure et induction asymetrique dans cette serie. Nous avons mis en evidence que l'encombrement sterique au niveau du centre metallique lors de l'epoxydation est le determinant principal de l'enantioselectivite. Ces resultats sont interpretes par un modele geometrique de l'approche de l'olefine vers le centre metallique. La complexation d'amines derivees d'olefines prochirales par les chiroporphyrines de cobalt (iii) a egalement ete etudiee.
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Gaudin, Jean-Marc. "Synthèses sélectives à l'aide de complexes du Palladium(0) : élaboration de chaine latérale de stéroïde (glaucastérol), phéromones et alpha-amino esters d'intérêts biologiques." Paris 6, 1986. http://www.theses.fr/1986PA066536.
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Ce travail porte sur l'utilisation de complexe du palladium (0) en catalyse homogène pour la synthèse de molécules d'intérêts biologiques. Trois applications y sont décrites: - la synthèse d'une phéromone secrétée par la reine des abeilles et d'une hormone végétale : l'acide traumatique. La construction du squelette carbone de ces molécules est basée sur une double alkylation d'une bis (aryl sulfonyl) méthane, l'une d'entre elles faisant intervenir un complexe eta (3) allyl palladien fonctionnalisé ; - la synthèse d'alpha-amino esters susceptibles d'être utilisés comme inhibiteur d'enzyme. Ceci est réalisé par l'alkylation catalysée d'une base de Schiff dérivée de la glycine. Quelques facteurs pouvant influencer l'énantiosélectivité de cette réaction ont été étudiés; - la synthèse de la chaine latérale du glaucasterol. Ce stéroïde marin isolé très récemment à la particularité de posséder dans sa structure un cyclopropane vinylique. La réaction clef est une cyclisation sn' catalysée. Elle s'effectue avec un transfert complet de la chiralité d'un benzoate allylique sur un des carbones cyclopropaniques et permet d'autre part le contrôle de la stéréochimie de la double liaison.
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Philippe, Josée. "Synthèse totale de l'acide majusculoïque et progrès vers la synthèse totale de la perhydrohistrionicotoxine." Thèse, 2007. http://hdl.handle.net/1866/17996.
Full textBook chapters on the topic "Cyclopropanol chiral"
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Jiang, G. J., Y. Wang, and Z. X. Yu. "Chiral Lewis Acid Catalyzed [3 + 3] Cycloadditions of Nitrones to Doubly Activated Cyclopropanes." In Stereoselective Pericyclic Reactions, Cross Coupling, and C—H and C—X Activation, 1. Georg Thieme Verlag KG, 2011. http://dx.doi.org/10.1055/sos-sd-203-00034.
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Taber, Douglass F. "Heteroaromatic Construction: The Jia Synthesis of (-)- cis -Clavicipitic Acid." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0065.
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Simultaneously, Aaran Aponick of the University of Florida (Organic Lett. 2009, 11, 4624) and Shuji Akai of the University of Shizuoka (Organic Lett. 2009, 11, 5002) reported the Au-mediate conversion of a propargylic diol such as 1 to the furan 2. Pyrroles can also be prepared using the same protocol. Jason K. Sello of Brown University developed (Organic Lett. 2009, 11, 2984) the direct aldol condensation of an acetoacetate 3 with the protected 1,3-dihydroxy acetone 4 to give 5, the methyl ester of a methylenomycin furan (MMF) bacterial-signaling molecule from Streptomyces coelicolor. Nobuharu Iwasawa of the Tokyo Institute of Technology demonstrated (Angew. Chem. Int. Ed. 2009, 48, 8318) that the imine 6 was sufficiently nucleophilic to react with the Rh vinylidene derived from the alkyne 7, leading to the pyrrole 8. Min Shi of the Shanghai Institute of Organic Chemistry extended (J. Org. Chem. 2009, 74, 5983) the reactivity of methylene cyclopropanes to the condensation of the aldehyde 9 with an acyl hydrazide, to give the pyrrole 11. Xue-Long Hou, also of the Shanghai Institute of Organic Chemistry, described (Tetrahedron Lett. 2009, 50, 6944) the Au-mediated reorganization of the alkynyl aziridine 12 to the pyrrole 13. Masahiro Yoshida of the University of Tokushima carried out (Tetrahedron Lett. 2009, 50, 6268) a similar rearrangement under oxidative conditions, giving the iodinated pyrrole 15. André M. Beauchemin of the University of Ottawa showed (Angew. Chem. Int. Ed. 2009, 48, 8325) that under acid catalysis, the oxime 16 cyclized to the pyridine 17. Shunsuke Chiba of Nanyang Technological University developed (J. Am. Chem. Soc. 2009, 131, 12570) the Mn(III)-mediated fusion of a cyclopropanol 18 with an alkenyl azide 19 to deliver the pyridine 20. Kazuaki Shimada of Iwate University found (Tetrahedron Lett. 2009, 50, 6651) that an isotellurazole such as 21, easily prepared from the corresponding alkyne, condensed with another alkyne 22, delivering the pyridine 23 with high regiocontrol. Christopher J. Moody of the University of Nottingham devised (Organic Lett. 2009, 11, 3686) a new route to the 1,2,4-triazine 24 from an α-diazoacetoacetate. He carried 24 on to the pyridine 26 by condensation with norbornadiene 25.
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Lambert, Tristan H. "C–O Ring Formation." In Organic Synthesis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190646165.003.0044.
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The enantioselective bromocyclization of dicarbonyl 1 to form dihydrofuran 3 using thiocarbamate catalyst 2 was developed (Angew. Chem. Int. Ed. 2013, 52, 8597) by Ying-Yeung Yeung at the National University of Singapore. Access to dihydrofuran 5 from the cyclic boronic acid 4 and salicylaldehyde via a morpholine-mediated Petasis borono-Mannich reaction was reported (Org. Lett. 2013, 15, 5944) by Xian-Jin Yang at East China University of Science and Technology and Jun Yang at the Shanghai Institute of Organic Chemistry. Chiral phosphoric acid 7 was shown (Angew. Chem. Int. Ed. 2013, 52, 13593) by Jianwei Sun at the Hong Kong University of Science and Technology to catalyze the enantioselective acetalization of diol 6 to form tetrahydrofuran 8 with high stereoselectivity. Jan Deska at the University of Cologne reported (Org. Lett. 2013, 15, 5998) the conversion of glutarate ether 9 to enantiopure tetrahydrofuranone 10 by way of an enzymatic desymmetrization/oxonium ylide rearrangement sequence. Perali Ramu Sridhar at the University of Hyderabad demonstrated (Org. Lett. 2013, 15, 4474) the ring-contraction of spirocyclopropane tetrahydropyran 11 to produce tetrahydrofuran 12. Michael A. Kerr at the University of Western Ontario reported (Org. Lett. 2013, 15, 4838) that cyclopropane hemimalonate 13 underwent conversion to vinylbutanolide 14 in the presence of LiCl and Me₃N•HCl under microwave irradiation. Eric M. Ferreira at Colorado State University developed (J. Am. Chem. Soc. 2013, 135, 17266) the platinum-catalyzed bisheterocyclization of alkyne diol 15 to furnish the bisheterocycle 16. Chiral sulfur ylides such as 17, which can be synthesized easily and cheaply, were shown (J. Am. Chem. Soc. 2013, 135, 11951) by Eoghan M. McGarrigle at the University of Bristol and University College Dublin and Varinder K. Aggarwal at the University of Bristol to stereoselectively epoxidize a variety of aldehydes, as exemplified by 18. The amine 20-catalyzed tandem heteroconjugate addition/Michael reaction of quinol 19 and cinnamaldehyde to produce bicycle 21 with very high ee was reported (Chem. Sci. 2013, 4, 2828) by Jeffrey S. Johnson at the University of North Carolina, Chapel Hill. Quinol ether 22 underwent facile photorearrangement–cycloaddition to 23 under irradiation, as reported (J. Am. Chem. Soc. 2013, 135, 17978) by John A. Porco, Jr. at Boston University and Corey R. J. Stephenson, now at the University of Michigan.
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Taber, Douglass. "Organocatalytic C-C Ring Construction: (+)-Ricciocarpin A (List) and (-)-Aromadendranediol (MacMillan)." In Organic Synthesis. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199764549.003.0073.
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Yoshiji Takemoto of Kyoto University designed (Organic Lett. 2009, 11, 2425) an organocatalyst for the enantioselective conjugate addition of alkene boronic acids to γ-hydroxy enones, leading to 1 in high ee. Attempted Mitsunobu coupling led to the cyclopropane 2, while bromoetherification followed by intramolecular alkylation delivered the cyclopropane 3. Jeffrey W. Bode of the University of Pennsylvania demonstrated (Organic Lett. 2009, 11, 677) a remarkable dichotomy in the reactivity of N-heterocyclic carbenes. A triazolium precatalyst combined 4 and 5 to give 6, whereas an imidazolium precatalyst combined 4 and 5 to give 7. Xinmiao Liang of the Dalian Institute of Chemical Physics and Jinxing Ye of the East China University of Science and Technology devised (Organic Lett. 2009, 11, 753) a Cinchona -derived catalyst that converted the prochiral cyclohexenone 8 into the diester 10 in high ee. Rich G. Carter of Oregon State University found (J. Org. Chem. 2009, 74, 2246) a simple sulfonamide-based proline catalyst that effected the Mannich condensation of the prochiral ketone with ethyl glyoxalate 12 and the amine 13, leading to the amine 14. In the first pot of a concise, three-pot synthesis of (-)-oseltamivir, Yujiro Hayashi of the Tokyo University of Science combined (Angew. Chem. Int. Ed. 2009, 48, 1304) 15 and 16 in the presence of a catalytic amount of diphenyl prolinol TMS ether to give an intermediate nitro aldehyde. Addition of the phosphonate 17 led to a cyclohexenecarboxylate, that on the addition of the thiophenol 18 equilibrated to the ester 19. Ying-Chun Chen of Sichuan University used (Organic Lett. 2009, 11, 2848) a related diaryl prolinol TMS ether to direct the condensation of the readily-prepared phosphorane 20 with the unsaturated aldehyde 21 to give the cyclohexenone 22. Armando Córdova of Stockholm University also used (Tetrahedron Lett. 2009, 50, 3458) diphenyl prolinol TMS ether to mediate the addition of 24 to 23. The subsequent intramolecular aldol condensation proceeded with high diastereocontrol, leading to 25. Benjamin List of the Max-Planck Institut, Mülheim employed (Nat. Chem. 2009, 1, 225) a MacMillan catalyst for the reductive cyclization of 26.
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Taber, Douglass F. "Heteroaromatic Construction: The Wipf Synthesis of Cycloclavine." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0068.
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Wesley J. Moran of the University of Huddersfield cyclized (Tetrahedron Lett. 2011, 52, 2605) a propargylated ketone 1 with Au to give the furan 2. Shengming Ma of the Shanghai Institute of Organic Chemistry found (Synlett 2011, 931) that tri(2-furyl)phosphine catalyzed the rearrangement of cyclopropene diesters, prepared by the addition of diazomalonate to alkynes, to the corresponding alkoxy furan 4. Xihe Bi and Qian Zhang of Northeast Normal University established (Chem. Commun. 2011, 47, 809) that a simple Fe catalyst effected the condensation of 5 with 6 to give the pyrrole 7. Gianfranco Favi of the Università degli Studi di Urbino showed (J. Org. Chem. 2011, 76, 2860) that the three-component coupling of 8 with an amine 9 and a ketone 10 proceeded without catalyst to deliver the pyrrole 11. Timothy J. Donohoe of the University of Oxford homologated (Org. Lett. 2011, 13, 1036) 12 by cross-metathesis with methyl vinyl ketone, to give, after oxidation and condensation with NH4OAc, the substituted pyridine 13. Dale L. Boger of Scripps/La Jolla condensed ( Org. Lett. 2011, 13, 2492) the unsubstitued 1,2,3-triazine 15 with an enamine 14 to give 16. Shunsuke Chiba of Nanyang Technological University prepared (J. Am. Chem. Soc. 2011, 133, 6411) the pyridine 19 by oxidizing the cyclopropanol 17 in the presence of the alkenyl azide 18. Limin Wang of the East China University of Science and Technology prepared (Tetrahedron Lett. 2011, 52, 509) the 2-aminopyridine 23 by the four-component coupling of the aldehyde 20 and the ketone 22 with NH4OAc and malononitrile 21. Taking advantage of the Knochel protocol for aryl Grignard formation, Christopher J. Moody of the University of Nottingham combined (Chem. Commun. 2011, 47, 788) the adduct from 24 with the ketone 25 to give the indole 26. Carsten Bolm of RWTH Aachen extended (Org. Lett. 2011, 13, 2012) the Fe catalysis reported by Zheng to the azide 27 to give 28. Sang-gi Lee of Ewha Womans University found (Org. Lett. 2011, 13, 1350) that the Blaise adduct from the addition of 29 to the nitrile could be cyclized to the indole 30.
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Taber, Douglass F. "Organocatalyzed C-C Ring Construction: The Thomson Synthesis of Streptorubin B." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0072.
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Jinxing Ye of the East China University of Science and Technology used (Tetrahedron Lett. 2011, 52, 2715) the Hayashi catalyst to direct the addition of 2 to 1, to give the cyclopropane 3. Jia-Rong Chen and Wen-Jing Xiao of Central China Normal University employed (J. Org. Chem. 2011, 76, 281) a urea catalyst for the addition of 5 to 4. Yasumasa Hamada of Chiba University devised (Tetrahedron Lett. 2011, 52, 987) a different urea catalyst for the addition of 7 to 8, to control both the absolute and relative configuration of 9. Jiyong Hong of Duke University showed (Tetrahedron Lett. 2011, 52, 2468) that the imidazolium-mediated cyclization of 10 proceeded with high diastereoselectivity to give 11. Yixin Lu of the National University of Singapore optimized (J. Am. Chem. Soc. 2011, 133, 1726) a dipeptide-derived phosphine to catalyze the addition of 12 to 13. Karl A. Scheidt of Northwestern University combined (Angew. Chem. Int. Ed. 2011, 50, 1678) a triazolium catalyst with super-stoichiometric Ti(O- i Pr)4 to effect the addition of 15 to 4, to give 16. En route to malyngamide C, Xiao-Ping Cao of Lanzhou University condensed (J. Org. Chem. 2011, 76, 3946) the prochiral commercial monoketal 17 with nitrosobenzene, using proline as a catalyst, to prepare 18. Hong Wang of Miami University showed (Angew. Chem. Int. Ed. 2011, 50, 3484) that a lanthanide-complexed α-amino amide was effective for catalyzing the addition of the prochiral 19 to 4, to give 20. Alexandre Alexakis of the Université de Genève and John C. Stephens of the National University of Ireland, Maynooth, established (Angew. Chem. Int. Ed. 2011, 50, 5095) that the Hayashi catalyst was effective for mediating the addition of 22 to 21, to give the diene 23. Ying-Chun Chen of Sichuan University and Karl Anker Jørgensen of Aarhus University used (J. Am. Chem. Soc. 2011, 133, 5053) the same catalyst for the addition of 24 to 25. The Hayashi catalyst appeared again in the report (Chem. Comm. 2011, 47, 3828) by Magnus Reuping of RWTH Aachen University of the addition of 27 to 28.
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Taber, Douglass F. "Selective Functionalization of C–H Bonds." In Organic Synthesis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190646165.003.0019.
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Jianhui Huang and Kang Zhao of Tianjin University devised (Chem. Commun. 2013, 49, 1211) a protocol for the oxidation of a terminal alkene 1 to the valuable four-carbon synthon 2. M. Christina White of the University of Illinois effected (J. Am. Chem. Soc. 2013, 135, 7831) the oxidation of the terminal alkene 3 to the enone 4. Miquel Costas of the Universitat de Girona developed (J. Org. Chem. 2013, 78, 1421; Chem. Eur. J. 2013, 19, 1908) a family of Fe catalysts for the oxidation of methylenes to ketones. Depending on the catalyst, any of the three ketones from the oxidation of 5, including 6, could be made the dominant product. Yumei Xiao and Zhaohai Qin of China Agricultural University optimized (Synthesis 2013, 45, 615) the Co-catalyzed oxidation of the methyl group of 7 to give the aldehyde 8. Thanh Binh Nguyen of CNRS Gif-sur-Yvette established (J. Am. Chem. Soc. 2013, 135, 118) a protocol (not illustrated) for the oxidation of methyl groups on heteroaromatics. Shunsuke Chiba of Nanyang Technological University cyclized (Org. Lett. 2013, 15, 212, 3214) the amidine 9 to 10, and the hydrazone 11 to 12. These cyclizations proceeded by sequential C–H abstraction followed by recombination, and so were racemizing. In contrast, the conversion of 13 to 14, developed (Science 2013, 340, 591) by Theodore A. Betley of Harvard University, proceeded with substantial retention of absolute configuration. Tsutomu Katsuki of Kyushu University designed (Angew. Chem. Int. Ed. 2013, 52, 1739) a Ru catalyst that was selective for the allylic position of the E-alkene 15 to give 16. Amination was highly regioselective, and proceeded with excellent ee. Ilhyong Ryu of Osaka Prefecture University and Maurizio Fagnoni of the University of Pavia reported (Org. Lett. 2013, 15, 2554) the direct carbonylation of 17 to the amide 18. David W. C. MacMillan of Princeton University devised (Science 2013, 339, 1593) a protocol for the β- arylation of an aldehyde 19 to give 20. Directed palladation of distal C–H bonds continues to be developed. Srinivasarao Arulananda Babu of the Indian Institute of Science Education and Research effected (Org. Lett. 2013, 15, 3238) diastereoselective arylation of the cyclopropane 21 with 22 to give 23.
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Taber, Douglass. "Organocatalytic Ring Construction: The Corey Synthesis of Coraxeniolide A." In Organic Synthesis. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199764549.003.0071.
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Armando Córdova of Stockholm University has found (Tetrahedron Lett. 2008, 49, 4209) that the organocatalyst 3a effected enantioselective conjugate addition of bromonitromethane 2 to the α,β-unsaturated aldehyde 1, to give the cyclopropane 4 as a ~ 1:1 diastereomeric mixture, both in high ee. Tomislav Rovis of Colorado State University has published (J. Org. Chem. 2008, 73, 2033) a detailed account of his development of catalysts such as 6, that effected enantioselective cyclization of 5 to 7 with excellent ee. Karl Anker Jørgensen of Aarhus University has employed (J. Am. Chem. Soc. 2008, 130, 4897) chiral quaternary salts derived from quinine that mediated the enantioselective addition of prochiral rings such as 8 to the allenoate ester 9 to give 10 with high ee. Organocatalysts have also been used to prepare more highly substituted cyclohexane derivatives. Guofu Zhong of Nanyang Technological University used (Organic Lett. 2008, 10, 2437) a quinine-derived secondary amine to catalyze the Michael addition of 12 to 11 followed by intramolecular aldol (Henry) reaction, to give 13. When Professor Jørgensen attempted (Angew. Chem. Int. Ed. 2008, 47, 121) the related addition of 14 and 15 using catalyst 3a, he did not observe the expected Michael-Michael sequence. Rather, the initial Michael addition was followed by a Morita-Baylis-Hillman condensation, to give 16. The β-keto ester 16 existed primarily in its enol form. Organocatalysts can also be used to prepare polycyclic systems. Professor Jørgensen has found (Chem. Commun. 2008, 3016) that condensation of 14 with acetone dicarboxylate 17, again using catalyst 3a, gave the bicyclic β-keto ester 18. Matthew J. Gaunt of the University of Cambridge observed (J. Am. Chem. Soc. 2008, 130, 404) that for the cyclization of 19, catalyst 3b was superior to catalyst 3a. The power of desymmetrization of prochiral intermediates was illustrated by the report (J. Am. Chem. Soc. 2008, 130, 6737) from Benjamin List of the Max-Planck-Institute, Mülheim of the cyclization of 21 to 23. Organocatalysts can also be used to prepare larger rings.
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Lambert, Tristan H. "C–O Ring Formation." In Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0049.
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A reductive radical cyclization of tetrahydropyran 1 to form bicycle 2 using iron(II) chloride in the presence of NaBH4 was reported (Angew. Chem. Int. Ed. 2012, 51, 6942) by Louis Fensterbank and Cyril Ollivier at the University of Paris and Anny Jutand at the Ecole Normale Supérieure. The enantioselective conversion of tetrahydrofuran 3 to spirocycle 5 via iminium ion-catalyzed hydride transfer/cyclization was developed (Angew. Chem. Int. Ed. 2012, 51, 8811) by Yong-Qiang Tu at Lanzhou University. Daniel Romo at Texas A&M University showed (J. Am. Chem. Soc. 2012, 134, 13348) that enantioenriched tricyclic β-lactone 8 could be readily prepared via dyotropic rearrangement of the diketoacid 6 under catalysis by chiral Lewis base 7. A dyotropic rearrangement was also utilized (Angew. Chem. Int. Ed. 2012, 51, 6984) by Zhen Yang at Peking University, Tuoping Luo at H3 Biomedicine in Cambridge, MA, and Yefeng Tang at Tsinghua University for the conversion of 9 to the bicyclic lactone 10. In terms of the enantioselective synthesis of β-lactones, Karl Scheidt at Northwestern University found that NHC catalyst 12 effects (Angew. Chem. Int. Ed. 2012, 51, 7309) the dynamic kinetic resolution of aldehyde 11 to furnish the lactone 13 with very high ee. Meanwhile, Xiaomeng Feng at Sichuan University has developed (J. Am Chem. Soc. 2012, 134, 17023) a rare example of an enantioselective Baeyer-Villiger oxidation of 4-alkyl cyclohexanones such as 14. The diastereoselective preparation of tetrahydropyran 18 by Lewis acid-promoted cyclization of cyclopropane 17 was accomplished (Org. Lett. 2012, 14, 6258) by Jin Kun Cha at Wayne State University. Stephen J. Connon at the University of Dublin reported (Chem. Commun. 2012, 48, 6502) the formal cycloaddition of aryl succinic anhydrides such as 18 with aldehydes to produce γ-butyrolactones, including 20, in high ee. The stereodivergent cyclization of 21 via desilylation-induced heteroconjugate addition to produce the complex tetrahydropyran 22 was discovered (Org. Lett. 2012, 14, 5550) by Paul A. Clarke at the University of York. Remarkably, while TFA produced a 13:1 diastereomeric ratio in favor of the cis diastereomer 22, the use of TBAF resulted in complete reversal of diastereoselectivity.
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Taber, Douglass F. "Organocatalytic Carbocyclic Construction: The Christmann Synthesis of (+)-Rotundial." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0069.
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Karl Anker Jørgensen of Aarhus University found (Angew. Chem. Int. Ed. 2009, 48, 6650) that an organocatalyst could mediate the fragmentation of the prochiral cyclopropane 1 with high ee to the easily epimerized product 2. Guofu Zhong of Nanyang Technological University devised (Angew. Chem. Int. Ed. 2009, 48, 6089) a dipolar cycloaddition strategy for the organocatalyzed combination of 3 and 4 with PhNHOH to give the highly substituted cyclopentane 5. Professor Jørgensen also established (Angew. Chem. Int. Ed. 2009, 48, 7338) that conjugate addition of 7 to the prochiral cyclohexenone 6 proceeded with high ee. The initial adduct could be converted into the alkene 8, the alkyne, or the ketone. Wen-Jing Xiao of Central China Normal University, following up on the work of Gong and Cheng, developed (Tetrahedron 2009, 65, 9238) a simple organocatalyst for the desymmetrizing Michael addition of 9 to 10 to give 11 with high de and ee. Control of sidechain chirality is an important aspect of carbocyclic construction. Samuel H. Gellman of the University of Wisconsin demonstrated (J. Am. Chem. Soc. 2009, 131, 16018) that the organocatalyzed addition of 13 to 12 proceeded with high facial selectivity and excellent diastereocontrol. In a complementary approach, Alexander J. A. Cobb of the University of Reading optimized (J. Am. Chem. Soc. 2009, 131, 16016) an organocatalyst for the cyclization of 15 to 16, again with high facial selectivity and excellent diastereocontrol. Ying-Chun Chen of the West China School of Pharmacy established (Organic Lett. 2009, 11, 4660) conditions for the organocatalyzed combination of 17 with 18 to give 19. In a related approach, Bor-Cherng Hong of the National Chung Cheng University showed (Organic Lett. 2009, 11, 5246) that 20, 21, and 22 could be combined under organocatalysis to give 23 in high ee with excellent diastereocontrol. Both of these approaches, and several others that have been published recently, were carried out with aryl substituents. It remains to be seen whether alkyl substituents, which would be more useful in a target-directed synthesis, would be compatible with these methods for ring construction.