Academic literature on the topic 'Alcohol synthesis; Organometallics'
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Journal articles on the topic "Alcohol synthesis; Organometallics"
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Narayanaperumal, Senthil, Ricardo S. Schwab, Wystan K. O. Teixeira, and Danilo Yano de Albuquerque. "Recent Advances in the Synthesis of Enantiomerically Enriched Diaryl, Aryl Heteroaryl, and Diheteroaryl Alcohols through Addition of Organometallic Reagents to Carbonyl Compounds." Synthesis 52, no. 13 (March 16, 2020): 1855–73. http://dx.doi.org/10.1055/s-0039-1690847.
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Enantiomerically enriched diaryl, aryl heteroaryl, and diheteroaryl alcohols are an important family of compounds known for their biological properties. Moreover, these molecules are highly privileged scaffolds used as building blocks for the synthesis of pharmaceutically relevant products. This short review provides background on the enantioselective arylation and heteroarylation of carbonyl compounds, as well as, the most significant improvements in this field with special emphasis on the application of organometallic reagents.1 Introduction2 Background on the Enantioselective Synthesis of Diaryl, Aryl Heteroaryl, and Diheteroaryl Alcohols3 Organozinc Reagents4 Organolithium Reagents5 Grignard Reagents6 Organoaluminum Reagents7 Organotitanium Reagents8 Organobismuth Reagents9 Miscellaneous10 Conclusion
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Chan, T. H., C. J. Li, M. C. Lee, and Z. Y. Wei. "1993 R.U. Lemieux Award Lecture Organometallic-type reactions in aqueous media—a new challenge in organic synthesis." Canadian Journal of Chemistry 72, no. 5 (May 1, 1994): 1181–92. http://dx.doi.org/10.1139/v94-151.
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The development of organometallic-type reactions in aqueous media is reviewed. Coupling reactions of allyl halides with carbonyl compounds mediated by zinc, or tin, or indium in aqueous media to give homoallylic alcohols are discussed. The stereochemical outcome is compared with similar reactions in organic solvents. A concise synthesis of (+)-muscarine is used to illustrate the usefulness of aqueous organometallic-type reactions in organic synthesis. The procedure to protect–deprotect hydroxy functional groups may not be necessary in these reactions. An application in the carbohydrate area is demonstrated with the synthesis of (+)-3-deoxy-D-glycero-D-galacto-nonulosonic acid (KDN). The mechanistic possibilities of organometallic-type reactions in aqueous media are outlined.
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Shu, Xing-Zhong, Feng-Feng Pan, Peng Guo, and Xiaochuang Huang. "Synthesis of Dibenzyls by Nickel-Catalyzed Homocoupling of Benzyl Alcohols." Synthesis 53, no. 17 (March 25, 2021): 3094–100. http://dx.doi.org/10.1055/a-1467-2432.
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AbstractDibenzyls are essential building blocks that are widely used in organic synthesis, and they are typically prepared by the homocoupling of halides, organometallics, and ethers. Herein, we report an approach to this class of compounds using alcohols, which are more stable and readily available. The reaction proceeds via nickel-catalyzed and dimethyl oxalate assisted dynamic kinetic homocoupling of benzyl alcohols. Both primary and secondary alcohols are tolerated.
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Elorriaga, David, María Jesús Rodríguez-Álvarez, Nicolás Ríos-Lombardía, Francisco Morís, Alejandro Presa Soto, Javier González-Sabín, Eva Hevia, and Joaquín García-Álvarez. "Combination of organocatalytic oxidation of alcohols and organolithium chemistry (RLi) in aqueous media, at room temperature and under aerobic conditions." Chemical Communications 56, no. 63 (2020): 8932–35. http://dx.doi.org/10.1039/d0cc03768k.
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Nicholas, Kenneth M., and Chandrasekhar Bandari. "Deoxygenative Transition-Metal-Promoted Reductive Coupling and Cross-Coupling of Alcohols and Epoxides." Synthesis 53, no. 02 (October 7, 2020): 267–78. http://dx.doi.org/10.1055/s-0040-1707269.
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AbstractThe prospective utilization of abundant, CO2-neutral, renewable feedstocks is driving the discovery and development of new reactions that refunctionalize oxygen-rich substrates such as alcohols and polyols through C–O bond activation. In this review, we highlight the development of transition-metal-promoted reactions of renewable alcohols and epoxides that result in carbon–carbon bond-formation. These include reductive self-coupling reactions and cross-coupling reactions of alcohols with alkenes and arene derivatives. Early approaches to reductive couplings employed stoichiometric amounts of low-valent transition-metal reagents to form the corresponding hydrocarbon dimers. More recently, the use of redox-active transition-metal catalysts together with a reductant has enhanced the practical applications and scope of the reductive coupling of alcohols. Inclusion of other reaction partners with alcohols such as unsaturated hydrocarbons and main-group organometallics has further expanded the diversity of carbon skeletons accessible and the potential for applications in chemical synthesis. Catalytic reductive coupling and cross-coupling reactions of epoxides are also highlighted. Mechanistic insights into the means of C–O activation and C–C bond formation, where available, are also highlighted.1 Introduction2 Stoichiometric Reductive Coupling of Alcohols3 Catalytic Reductive Coupling of Alcohols3.1 Heterogeneous Catalysis3.2 Homogeneous Catalysis4 Reductive Cross-Coupling of Alcohols4.1 Reductive Alkylation4.2 Reductive Addition to Olefins5 Epoxide Reductive Coupling Reactions6 Conclusions and Future Directions
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Cicco, Luciana, María J. Rodríguez-Álvarez, Filippo M. Perna, Joaquín García-Álvarez, and Vito Capriati. "One-pot sustainable synthesis of tertiary alcohols by combining ruthenium-catalysed isomerisation of allylic alcohols and chemoselective addition of polar organometallic reagents in deep eutectic solvents." Green Chemistry 19, no. 13 (2017): 3069–77. http://dx.doi.org/10.1039/c7gc00458c.
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Vizer, S. A., and K. B. Yerzhanov. "Heterocycles Synthesis at Carbonylation of Acetylenic Compounds." Eurasian Chemico-Technological Journal 5, no. 2 (April 5, 2016): 145. http://dx.doi.org/10.18321/ectj294.
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The carbonylation of unsaturated hydrocarbons, alcohols, organic halides and other substrates catalyzed by transition metals, salts of transition metals and organometallic complexes is a wide used synthesis method of new carbonyl, carboxyl and alkoxy carbonyl containing compounds including creation or modificationt of heterocycles. The data about synthesis of heterocycles at carbonylation of acetylenic compounds have been appeared at last 20 years and are demonstrated in our review. Introduction of carbon monoxide in the catalytic reactions of acetylenic compounds permits to obtain in oneput process the diverse heterocycles, having carbonyl, carboxyl or alkoxycarbonyl substitutes or containing these fragments inside of heterocycles.
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Gheorghievici, Gavril Lucian, Corneliu Trisca Rusu, Elena Voicila, Ion Marius Nafliu, Anca Maria Cimbru, and Szidonia Katalin Tanczos. "Titanium Dioxide for Biomedical Uses I. The controlled production of nanoparticles by hidrothermal synthesis moderated by dimedone." Revista de Chimie 68, no. 1 (February 15, 2017): 11–15. http://dx.doi.org/10.37358/rc.17.1.5378.
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The controlled the solvo-hydro-thermal titanium dioxide synthesis moderated by dimedone from organometallic precursors is approached in order to obtain nanoparticles compatible with the polymeric systems used in the dental technique. The experiments carried out with relation to the production of titanium dioxide nanoparticles using the solvo-hydro-thermal synthesis allowed the production of three types of materials by means of varying the nature of the used solvent: methanol, ethanol and propanol (TiO2-M, TiO2-E and TiO2-P).The characterisation using electron microscopy (SEM and HRTEM), X-ray analysis, FTIR and UV-Vis spectrometry show that the diameter of the produced nanoparticles is less than 15 nm and decreases in the order: dpMethanol ] dpEthanol ] dpPropanol. The nanoparticles contain trace organic substances which the smaller they are, the bigger the alcohol chain used as a solvent is. The adsorption of a target dye showed increasing values with the increasing number of atoms in the hydrocarbon alcohol chain. The highlighted characteristics suggest the possibility of using the synthesised nanoparticles in the production of hard implants for dental reconstruction.
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Loughrey, Bradley T., Michael L. Williams, Thomas J. Carruthers, Peter G. Parsons, and Peter C. Healy. "Synthesis, Structure, and Selective Cytotoxicity of Organometallic Cp*RuII O-Alkyl-N-phenylcarbamate Sandwich Complexes." Australian Journal of Chemistry 63, no. 2 (2010): 245. http://dx.doi.org/10.1071/ch09420.
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Tetraphenylborate salts of the η6-arene Cp*RuII O-alkyl-N-phenyl carbamate organometallic sandwich complexes, [Cp*Ru(PhNHCO2R)]BPh4 for R = Me (1), Et (2), and n-Pr (3), have been prepared by a facile one-pot reaction between ruthenium trichloride, pentamethylcyclopentadiene, and phenylisocyanate in refluxing alcohol solutions, and have been characterized by Fourier-transform IR and NMR spectroscopy, electrospray mass spectrometry, and single-crystal X-ray structure determinations. In vitro cytotoxicity studies show the complexes to be potent growth inhibitors for a range of tumour cell lines, while expressing significantly lower levels of toxicity towards a normal human fibroblast cell line.
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Larock, Richard C., and Sandra K. Stolz-Dunn. "Synthesis of Homoallylic Alcohols via Organometallic Ring Opening of Vinylic Oxetanes." Synlett 1990, no. 06 (1990): 341–43. http://dx.doi.org/10.1055/s-1990-21086.
Full textDissertations / Theses on the topic "Alcohol synthesis; Organometallics"
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Loveridge, Tracey. "Chiral chromium complexes in synthesis." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296868.
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Fernández, Mateos Emilio. "New methodologies for the catalytic enantioselective addition of organometallic reagents to carbonyl compounds." Doctoral thesis, Universidad de Alicante, 2015. http://hdl.handle.net/10045/50227.
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Notar, Francesco Irène. "New methodologies in organometallic chemistry : application to the synthesis of mandelate derivatives, propargylic alcohols and P-chirogenic phosphinamides." Strasbourg, 2010. https://publication-theses.unistra.fr/public/theses_doctorat/2010/NOTAR_FRANCESCO_Irene_2010.pdf.
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Au cours des dernières décennies, la chimie et la catalyse organométallique ont très largement contribué aux progrès de la chimie organique moderne, par l’apport de nouvelles méthodes synthétiques qui ont capturé l’intérêt des milieux académiques et industriels. Le travail présenté se compose de trois différentes parties chacune dédiée à une réaction différente dans le cadre de la chimie organométallique et qui a permis la synthèse d’importants motifs moléculaires tels que esters mandéliques, alcools propargyliques et phosphinamides P-chirogéniques. Dans la première partie on a présenté une nouvelle méthodologie de synthèse racémique et stéréosélective de dérivés de l’acide mandélique par couplage pallado-catalysé entre un acide boronique aromatique et plusieurs esters glyoxyliques. La seconde partie est consacrée à l’addition d’alkynylborates de lithium sur des aldéhydes dans le cadre d’une approche chimiosélective vers la synthèse d’alcools propargyliques hautement fonctionnalisés. Dans la dernière partie du manuscrit nous avons présenté la synthèse de nouvelles N-phosphinoylimines P-chirogéniques ou chirales par la présence d’une agrafe chirale dérivée du TADDOL. L’évaluation de la diastéréosélectivité issue du groupement chirale adjacent à la double liaison C,N a été effectué sur la base de la réaction d’addition 1,2 d’organomagnésiensOver the last decades, organometallic chemistry and catalysis contributed to the progress of modern organic chemistry, affording new synthetic methods used not only for the synthesis in laboratory, but also in industry. The presented work deals with three different organometallic reactions leading to key molecular motifs: mandelic esters, propargylic alcohols and phosphinoyl amides. In the first part we have thus presented the cross coupling reaction between aromatic boronic acids and ethyl glyoxylate as a catalytic approach to alpha-hydroxy esters. We also discussed the results obtained with enantio- and diastereoselective strategies. The second part treats the addition of lithium alkynylborates, as a truly original and chemoselective approach toward the synthesis of highly functionalized propargyl alcohols. In the last part of the manuscript we have introduced the synthesis of new P-chirogenic or chiral for the inducer derived from TADDOL directly linked to the P atom, N-phosphinoyl imines. The evaluation of the diastereoselectivity derived from the chiral inducer close to the C, N double bond have been done by the 1,2 addition of organometallic reagents
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Lhomme, Julien. "Nouveaux catalyseurs et systèmes catalytiques appliqués à la synthèse du polyuréthane via la réaction isocyanate – alcool." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0158/document.
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L’objectif de ce travail est de remplacer les catalyseurs organométalliques à base d’étain et de mercure utilisés lors de la synthèse de polyuréthane via la réaction isocyanate – alcool. Une étude bibliographique a montré que la basicité et la nucléophilie d’un catalyseur organique gouvernent son activité et le mécanisme réactionnel qu’il induit. Pour les catalyseurs organométalliques, ces propriétés catalytiques s’expliquent par des considérations électroniques ainsi que par le principe HSAB. D’autre part, une étude approfondie du catalyseur organomercuriel a été menée. Elle a révélé l’intérêt d’ajouter à l’espèce catalytique organométallique un acide carboxylique, de préférence à longue chaîne carbonée. Celui-ci ralentit l’hydrolyse du catalyseur tout en augmentant sa sélectivité envers la réaction isocyanate – alcool. De nouveaux catalyseurs ou systèmes catalytiques originaux ont ensuite été évalués grâce à un test simplifié. Trois catalyseurs organométalliques ont ainsi été sélectionnés pour de nouveaux essais dans des conditions plus proches de celles rencontrées dans l’industrie. Ils se sont tous révélés actifs, mais seul le -dicétonate de zinc II permet d’obtenir un prépolymère incolore et transparent, deux critères essentiels pour les applications visées. Il pourrait donc remplacer le catalyseur organostannique. Enfin, l’étude de la sélectivité de systèmes catalytiques impliquant un catalyseur commercial en présence d’acide néodécanoïque a confirmé le rôle protecteur de ce dernier. La sélectivité du complexe de zinc retenu précédemment a par ailleurs été évaluée et apparaît 2,5 fois supérieure à celle du complexe organomercuriel à remplacerThe aim of this work is to replace organotin and organomercury catalysts used for the synthesis of polyurethane via the isocyanate – alcohol reaction. A bibliographic review revealed that basicity and nucleophilicity of an organic catalyst affect its activity and the reaction mechanism it induces. For organometallic catalysts, these catalytic properties can be explained by electronic considerations and by the HSAB principle. On the other hand, a comprehensive study of the organomercury catalyst highlighted the benefit to combine it with a carboxylic acid, preferably with a long carbon backbone. This slows down hydrolysis of the catalyst while increasing its selectivity toward the isocyanate – alcohol reaction. New original catalysts or catalytic systems were then evaluated using a simplified experiment. Three organometallic catalysts were selected for further testing in conditions closer to industrial ones. They all showed appropriate catalytic activity, but the zinc II -diketonate is the only one to provide a colorless and transparent prepolymer, two essential criteria for the intended applications. This complex could therefore replace the organotin catalyst. Finally, the study of the selectivity of catalytic systems involving a commercial catalyst in the presence of neodecanoic acid confirmed its protective role toward hydrolysis. The previously retained zinc complex was also evaluated and revealed a selectivity 2.5 times greater than that of the organomercurial complex to replace
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Carlos, de Souza Barboza Jayne. "Effets des ultra-sons sur la formation et les réactions des organozinciques et organolithiens." Grenoble 1, 1987. http://www.theses.fr/1987GRE10145.
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L'influence des ultrasons sur la formation des organolithiens a ete etudiee a l'aide d'une reaction de barbier. L'influence de la temperature de reaction et celle de l'energie ultrasonore ont ete mises en evidence par des methodes cinetiques et par microscopie electronique. Les organozinciques s'additionnent de facon conjuguee sur les enones et enaldehydes
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Hesse, Andrew J. "Nontraditional synthesis of organometallic compounds and allylic alcohols /." 2007. http://digitalcommons.butler.edu/ugtheses/52/.
Full textBook chapters on the topic "Alcohol synthesis; Organometallics"
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Breit, Bernhard. "Substrate Directed Diastereoselective Hydroformylation of Methallylic Alcohols." In Organic Synthesis via Organometallics OSM 5, 139–46. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-49348-5_10.
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Taber, Douglass F. "Establishing Arrays of Stereogenic Centers: The Sato/Chida Synthesis of (-)-Kainic Acid." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0046.
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Benjamin List of the Max-Planck-Institut, Mülheim, devised (J. Am. Chem. Soc. 2010, 132, 10227) a catalyst system for the stereocontrolled epoxidation of a trisubstituted alkenyl aldehyde 1. Takashi Ooi of Nagoya University effected (Angew. Chem. Int. Ed. 2010, 49, 7562; see also Org. Lett. 2010, 12, 4070) enantioselective Henry addition to an alkynyl aldehyde 3. Madeleine M. Joullié of the University of Pennsylvania showed (Org. Lett. 2010, 12, 4244) that an amine 7 added selectively to an alkynyl aziridine 6. Yutaka Ukaji and Katsuhiko Inomata of Kanazawa University developed (Chem. Lett. 2010, 39, 1036) the enantioselective dipolar cycloaddition of 9 with 10. K. C. Nicolaou of Scripps/La Jolla observed (Angew. Chem. Int. Ed. 2010, 49, 5875; see also J. Org. Chem. 2010, 75, 8658) that the allylic alcohol from enantioselective reduction of 12 could be hydrogenated with high diastereocontrol. Masamichi Ogasawara and Tamotsu Takahashi of Hokkaido University added (Org. Lett. 2010, 12, 5736) the allene 14 to the acetal 15 with substantial stereocontrol. Helen C. Hailes of University College London investigated (Chem. Comm. 2010, 46, 7608) the enzyme-mediated addition of 18 to racemic 17. Dawei Ma of the Shanghai Institute of Organic Chemistry, in the course of a synthesis of oseltamivir (Tamiflu), accomplished (Angew. Chem. Int. Ed. 2010, 49, 4656) the enantioselective addition of 21 to 20. Shigeki Matsunaga of the University of Tokyo and Masakatsu Shibasaki of the Institute of Microbial Chemistry developed (Org. Lett. 2010, 12, 3246) a Ni catalyst for the enantioselective addition of 23 to 24. Juthanat Kaeobamrung and Jeffrey W. Bode of ETH-Zurich and Marisa C. Kozlowski of the University of Pennsylvania devised (Proc. Natl. Acad. Sci. 2010, 107, 20661) an organocatalyst for the enantioselective addition of 27 to 26. Yihua Zhang of China Pharmaceutical University and Professor Ma effected (Tetrahedron Lett. 2010, 51, 3827) the related addition of 27 to 29. There have been scattered reports on the stereochemical course of the coupling of cyclic secondary organometallics. In a detailed study, Paul Knochel of Ludwig-Maximilians- Universität München showed (Nat. Chem. 2020, 2, 125) that equatorial bond formation dominated, exemplified by the conversion of 31 to 33.
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EISCH, JOHN J., JAMES E. GALLE, and MIIN-RONG TSAI. "α-(TRIMETHYLSILYL)BENZYL ALCOHOL." In Organometallic Syntheses, 491–93. Elsevier, 1988. http://dx.doi.org/10.1016/b978-0-444-42956-8.50141-9.
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Perkins, M. V. "Synthesis Using Other Organometallic Reagents." In Alcohols, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-036-00575.
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Taber, Douglass. "The Castle Synthesis of (-)-Acutumine." In Organic Synthesis. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199764549.003.0104.
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The complex tetracyclic alkaloid (-)-acutumine 3, isolated from the Asian vine Menispermum dauricum, shows selective T-cell toxicity. The two adjacent cyclic all-carbon quaternary centers of 3 offered a particular challenge. Steven L. Castle of Brigham Young University solved (J. Am. Chem. Soc. 2009, 131, 6674) this problem by effecting net enantioselective conjugate allylation of the enantiomerically pure substrate 1 to give 2 with high diastereocontrol. The starting coupling partners ( Organic Lett . 2006, 8, 3757; Organic Lett. 2007, 9, 4033) for the synthesis were the Weinreb amide 4, prepared over several steps from 2,3- dimethoxyphenol, and the diastereomerically- and enantiomerically-pure cyclopentenyl iodide 5, prepared by singlet oxygenation of cyclopentadiene followed by enzymatic hydrolysis. Transmetalation of 5 by the Knochel protocol, addition of the resulting organometallic to 4 and enantioselective (and therefore diastereoselective) reduction of the resulting ketone delivered the alcohol 6. Methods for installing cyclic halogenated stereogenic centers are not well developed. Exposure of the allylic alcohol to mesyl chloride gave the chloride 7 with inversion of absolute configuration. Remarkably, this chlorinated center was carried through the rest of the synthesis without being disturbed. A central step in the synthesis of 3 was the spirocyclization of 7 to 8. Initially, iodine atom abstraction generated the aryl radical. The diastereoselectivity of the radical addition to the cyclopentene was set by the adjacent silyloxy group. The α-keto radical so generated reacted with the Et3Al to give a species that was oxidized by the oxaziridine to the α-keto alcohol, again with remarkable diastereocontrol. Conjugate addition to the cyclohexenone 1 failed, so an alternative strategy was developed, diastereoselective 1,2-allylation of the ketone followed by oxy-Cope rearrangement. The stereogenic centers of 1 are remote from the cyclohexenone carbonyl, so could not be used to control the facial selectivity of the addition. Fortunately, the stoichiometric enantiomerically-pure Nakamura reagent delivered the allyl group preferentially to one face of the ketone 1, to give 9. The subsequent sigmatropic rearrangement to establish the very congested second quaternary center of 2 then proceeded with remarkable facility, at 0°C for one hour.
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Taber, Douglass F. "The Nakada Synthesis of (-)-FR182877." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0084.
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The Streptomyces metabolite (-)-FR182877 3 binds to and stabilizes microtubules, showing the same potency of anticancer activity as Taxol (paclitaxel). Masahisa Nakada of Waseda University assembled (Angew. Chem. Int. Ed. 2009, 48, 2580) the hexacyclic ring system of 3 by the tandem intramolecular Diels-Alder–intramolecular hetero Diels-Alder cyclization of 1, generating seven new stereogenic centers in a single step. The construction of the pentaene substrate 1 started with the known aldehyde 4, prepared by homologation of commercial ethyl 3-methyl-4-oxocrotonate. Addition of the propionyl oxazolidine anion 5 proceeded with high diastereocontrol, to give 6. The acyl oxazolidinone was not an efficient acylating agent, so it was converted to the Weinreb amide. Protection and deprotection then delivered the allylic acetate 7. The key step in the pentaene assembly was the carefully optimized Negishi-Wipf methylation of 8, followed by Pd-mediated coupling of the alkenyl organometallic so generated with the allylic acetate, to give 9. Condensation of the derived keto phosphonate 11 with the known aldehyde 12 then delivered the enone 13. The Nakada group has worked extensively on the intramolecular Diels-Alder reaction of substrates such as 1. They have shown that protected anti diols such as 1 cyclize with substantial diastereocontrol and in the desired sense. In contrast, cyclizations of protected syn diols proceed with poor diastereocontrol. The enone 13 was therefore reduced to the anti diol and protected, leading to 14 . Oxidation of 14 at room temperature led to a complex mixture, but slow oxidation at elevated temperature delivered 2 . Although the yield of 2 was not much better than if the reactions were carried out sequentially, first the intramolecular Diels-Alder cyclization, then the intramolecular hetero Diels-Alder cyclization, with the cascade protocol pure 2 was more readily separated from the reaction matrix. With 2 in hand, there was still the challenge of assembling the seven-membered ring. Cyclization was effected with an intramolecular Heck protocol. The two diastereomers of the allylic alcohol 15 cyclized with comparable efficiency. Ir-catalyzed alkene migration then converted the allylic alcohols to a mixture of ketones, which was equilibrated to give the more stable diasteromer.
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Taber, Douglass. "The Betzer and Ardisson Synthesis of (+)-Discodermolide." In Organic Synthesis. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199764549.003.0085.
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( + )-Discodermolide 3, a potent anticancer agent that works synergistically with taxol, may yet prove to be clinically effective. For the synthetic material to be affordable, a highly convergent synthesis is required. Jean-François Betzer and Janick Ardisson of the Université de Cergy- Pontoise have described (Angew. Chem. Int. Ed. 2007, 46, 1917) such a synthesis, coupling 1 and 2. A central feature of their approach was the repeated application of the inherently chiral secondary organometallic reagent 5. The first use of 5 was the addition to the aldehyde 4. The product 6 was ozonized, and the resulting aldehyde was carried on to the α, β-unsaturated ester. Exposure of the hydroxy ester to benzaldehyde under basic conditions delivered, by intramolecular Michael addition, the acetal 7. The next addition of the reagent 5 was to the aldehyde 10. The adduct 11 was deprotonated with t-BuLi to effect α-elimination, providing, after protection of the alcohol, the alkyne 12. Coupling of 12 with the amide 7 gave a ketone, enantioselective reduction of which under Itsuno-Corey conditions led, again after protection of the alcohol, to the alkyne 13. Oxidation followed by selective hydrogenation and iodine-tin exchange then completed the assembly of 1. Note that PtO2, not typically used for partial hydrogenation, was the catalyst of choice for this congested alkyne. The third application of the enantiomerically-pure reagent 5 was addition to the aldehyde that had been prepared by ozonolysis of 15. Advantage was then taken of another property of the alkenyl carbamate, Ni-mediated Grignard coupling, to form the next carbon-carbon bond with high geometric control. Deprotection of the diene 17 so prepared followed by iodination then completed the synthesis of 2. The convergent coupling of 1 with 2 was carried out under Suzuki conditions. Reduction of the iodide of 2 to the corresponding alkyl lithium followed by exchange with B-OMe-9-BBN gave an intermediate organoborane, that smoothly coupled with 1 under Pd catalysis to give 18.
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Doraiswamy, L. K. "Homogeneous Catalysis." In Organic Synthesis Engineering. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780195096897.003.0014.
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Catalysis by soluble complexes of transition metals is a rapidly gaining mode of catalysis in organic synthesis. These metals form bonds with one or more carbons in an organic reactant resulting in complexes that are known as organometallic complexes. Catalysis by these complexes is often referred to as homogeneous catalysis. Among the important applications of homogeneous catalysis in organic synthesis are isomerization of olefins; hydrogenation of olefins (carried out using Wilkinson type catalysts); oligomerization; hydroformylation of olefins to aldehydes with CO and H2 (the oxo process); carbonylation of unsaturated hydrocarbons and alcohols with CO (and coreactants such as water); oxidation of olefins to aldehydes, ketones, and alkenyl esters (Wacker process); and metathesis of olefins (a novel kind of disproportionation). Enantioselective catalysis that rivals enzymes in selectivity is a major development in homogeneous catalysis. As a result, many earlier processes in the pharmaceutical and perfumery industries are being replaced by more elegant syntheses using soluble catalysts in which “handedness” is introduced in the critical step of the process, thus avoiding the costly separation of racemic mixtures. In view of its importance in organic synthesis, enantioselective (or asymmetric) catalysis was briefly introduced in Chapter 6 and is again considered as a powerful synthetic tool in Chapter 9. This chapter is concerned with the use in general of homogeneous catalysis in organic synthesis (including asymmetric synthesis). Among the several books and reviews written on the subject, the following may be mentioned: Halpern (1975, 1982), Bau et al. (1978), Parshall (1980), Masters (1981), Collman and Hegedus (1980), Eby and Singleton (1983), Chaudhari (1984), Davidson (1984), Kegley and Pinhas (1986), Collman et al. (1987), Parshall and Nugent (1988), Noyori and Kitamura (1989), Parshall and Ittel (1992), Gates (1992), Chan (1993), Akutagawa (1995). Gas (or liquid)-phase reactions on solid catalysts are among the most common industrial reactions. However, homogeneous catalysis is rapidly catching up. Excluding applications in petroleum refining, the dollar value of organic chemicals produced worldwide by homogeneous catalysis (more than $35 billion) is quite impressive compared to that by heterogeneous catalysis (more than $45 billion). Attempts are now under way to find an integrated approach to homogeneous and heterogeneous catalyses (Moulijn et al., 1993).
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Taber, Douglass F. "Construction of Arrays of Stereogenic Centers: The Zhang Synthesis of (+)-Podophyllotoxin." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0043.
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Varinder K. Aggarwal of the University of Bristol showed (Angew. Chem. Int. Ed. 2009, 48, 1149) that condensation of a boronic ester 2 with a metalated aziridine 1 led, after oxidation, to the defined amino alcohol 3. Hisashi Yamamoto of the University of Chicago developed (Angew. Chem. Int. Ed. 2009, 48, 3333) conditions for the diastereoselective addition of an organometallic to an α-nitrosylated aldehyde, to give, after reduction, the diol 6. Xiaoyu Wu of Shanghai University and Gang Zhao of the Shanghai Institute of Organic Chemistry designed (Adv. Synth. Cat. 2009, 351, 158) an organocatalyst that mediated the enantioselective addition of hydroxyacetone 7 to a range of aldehydes. Andrew G. Myers of Harvard University found (J. Am. Chem. Soc. 2009, 131, 5763) that trialkylaluminum reagents opened epoxides of enol ethers at the more substituted position, delivering protected diols such as 10. Keiji Maruoka of Kyoto University created (Angew. Chem. Int. Ed. 2009, 48, 1838) an organocatalyst for the addition of an aldehyde 11 to an imine 12, to give 13. Markus Kalesse of Leibnitz Universität Hannover showed (Tetrahedron Lett. 2009, 50, 3485) that an organocatalyst could mediate the selective γ-reactivity of 15, leading to 16. Barry M. Trost of Stanford University found (J. Am. Chem. Soc. 2009, 131, 1674) that an organocatalyst directed the addition of diazoacetate 18 to an aldehyde, to give, after further reaction with a trialkylborane, the syn aldol product 19. Professor Trost also demonstrated (J. Am. Chem. Soc. 2009, 131, 4572) that a related complex mediated the conjugate addition of 22 to 21. Enantioselective construction of arrays of alkylated stereogenic centers is a particular challenge. Ji Zhang, then at Pfizer, found (Tetrahedron Lett. 2009, 50, 1167) that the chiral auxiliary of 24 directed both the conjugate addition and the subsequent protonation, and also allowed the product 25 to be brought to > 98% purity by crystallization. Tönis Kanger of Tallinn University of Technology developed (J. Org. Chem. 2009, 74, 3772) an organocatalyst for the conjugate addition of aldehydes to nitrostyrenes such as 26 to give 27.
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Taber, Douglass F. "Carbon–Carbon Bond Formation: The Bergman Synthesis of (+)-Fuligocandin B." In Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0024.
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Xile Hu of the Ecole Polytechnique Fédérale de Lausanne optimized (J. Am. Chem. Soc. 2011, 133, 7084) a Ni catalyst for the coupling of a Grignard reagent 2 with a secondary alkyl halide 1. Duk Keun An of Kangwon National University devised (Tetrahedron Lett. 2011, 52, 1718; Chem. Commun. 2011, 47, 3281) a strategy for the reductive coupling of an ester 4 with a Grignard reagent 2 to give the secondary alcohol. Daniel J. Weix of the University of Rochester added (Org. Lett. 2011, 13, 2766) the halide 7 in a conjugate sense to the bromoenone 6, setting the stage for further organometallic coupling. James Y. Becker of the Ben-Gurion University of the Negev effected (J. Org. Chem. 2011, 76, 4710) Kolbe coupling of the silyl acid 9 to give the decarboxylated dimer 10. Shi-Kai Tian of USTC Hefei showed (Chem. Commun. 2011, 47, 2158) that depending on the sulfonyl group used, the coupling of 11 with 12 could be directed cleanly toward either the Z or the E product. Yoichiro Kuninobu and Kazuhiko Takai of Okayama University added (Org. Lett. 2011, 13, 2959) the sulfonyl ketone 14 to the alkyne 13 to form the trisubstituted alkene 15. Jianbo Wang of Peking University assembled (Angew. Chem. Int. Ed. 2011, 50, 3510) the trisubstituted alkene 18 by adding the diazo ester 16 to the alkyne 17. Gangguo Zhu of Zhejiang Normal University constructed (J. Org. Chem. 2011, 76, 4071) the versatile tetrasubstituted alkene 21 by adding the chloroalkyne 19 to acrolein 20. Other more substituted acceptors worked as well. Chunxiang Kuang of Tongji University and Qing Yang of Fudan University effected (Tetrahedron Lett. 2011, 52, 992) elimination of 22 to 23 by stirring with Cs2CO3 at 115°C in DMSO overnight. Toshiaki Murai of Gifu University created (Chem. Lett. 2011, 40, 70) a propargyl anion by condensing 24 with 25 then adding 26. Xiaodong Shi of West Virginia University found (Org. Lett. 2011, 13, 2618) that the enantiomerically enriched propargyl ether 29 could be rearranged to the trisubsituted allene 30 with retention of the ee and with high de.