Dissertations / Theses: 'Dienophiles'

1

Siberdt, Fabian. "Action de dienophiles sur les 2-vinylindolizines." Doctoral thesis, Universite Libre de Bruxelles, 1995. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212576.

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Lochrie, Ian Stewart Tolmie. "Investigation of diastereomeric induction in the Diels-Alder reactions of acylnitroso dienophiles." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320289.

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3

Youssofi, Abdullah. "Etude des dichloroboranes vinyliques en tant que dienophiles. Application a la synthese stereocontrolee d'heterocycles bicycliques azotes et oxygenes." Rennes 1, 1994. http://www.theses.fr/1994REN10186.

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Ce memoire traite de l'etude de la synthese des dichloroboranes ,b-insatures ainsi que de l'etude de leur reactivite dans la reaction de diels-alder. Dans le premier chapitre, nous avons etudie la synthese des vinyldichloroboranes de configuration e en realisant une monohydroboration des alcynes vrais par hbcl#2 genere in situ. L'acces aux vinyldichloroboranes z, ainsi que l'haloboration des alcynes vrais ont egalement ete abordes par quelques exemples. Dans le deuxieme chapitre, nous avons etudie la reactivite des vinyldichloroboranes obtenus dans la reaction de diels-alder. Nous obtenons des cyclohexenols exclusivement cis ou trans par oxydation des adduits de la cycloaddition. L'alkylation reductrice du benzylazide, suivie de l'hydrolyse conduit aux chlorhydrates des cyclohexenylamines de configuration exclusivement cis ou trans. Lorsque l'alcyne de depart est convenablement choisi, a partir des adduits sous forme d'alcools ou de chlorhydrate d'amines, par simple passage en milieu basique, on obtient des composes bicycliques azotes ou oxygenes. Ces composes heterocycliques bicycliques sont a jonction exclusivement cis ou trans. Il s'agit d'une nouvelle voie d'acces a ces composes

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4

LAMEIGNERE, ERIC. "Synthese de dienes et de dienophiles pyranosidiques en vue de leur utilisation dans la synthese de molecules naturelles polycycliques." Paris 11, 1990. http://www.theses.fr/1990PA112032.

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Cette these tente d'illuster l'interet qu'il est possible de tirer de l'integration de dienes et de dienophiles pyranosidiques dans un schema synthetique. Ces composes etant utilises lors de reactions de diels-alder afin d'obtenir des heterocycles, qui sont des precurseurs de molecules naturelles polycycliques. Le premier chapitre presente deux voies de synthese originales nous ayant permis d'obtenir huit dienes pyranosidiques ainsi que sept aldehydes insatures. Ces derniers pouvant etre utilises soit comme dienophiles soit comme heterodienes. Dans le deuxieme chapitre, nous presentons les resultats obtenus en faisant reagir deux des dienes pyranosidiques avec des dienophiles comme l'anhydride maleic ou le dimethyleacethylene dicarboxylate. Enfin, le troisieme chapitre presente deux exemples d'utilisation synthetique des aldehydes insatures obtenus lors du premier chapitre. La reaction de ces derniers avec le butadiene et l'ethyle vinyle ether est etudiee

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5

Haquin, Catherine. "Diaza-1,3 butadienes et isothiocyanates d'imidoyle : cycloaddition (1+4) avec les isonitriles et cycloaddition (2+4) avec quelques dienophiles electrophiles." Rennes 1, 1987. http://www.theses.fr/1987REN10036.

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Mise au point d'une methode d'acces aux s-alkyl ou s-aryl n-methylene carbaminidate et aux isothiocyanatothioformimidates de s-alkyles ou de s-aryles. Ces composes ont ete utilises pour realiser la synthese d'heterocycle (par exemple des triazadithiapentalenes)

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6

Yu, Jianguo. "Novel chiral phosphonium ionic liquids as solvents and catalysts for cycloadditions : investigation of the Diels-Alder reaction of a series of dienes and dienophiles in novel chiral phosphonium ionic liquids." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4307.

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The use of ionic liquids (ILs) as both reagents and solvents is widely recognised. ILs offer a number of advantages compared to regular molecular solvents. These advantages include: chemical and thermal stability, no measurable vapour pressure, no or lower toxicity, non-flammability, catalytic ability, high polarity and they can be recycled. There are a number of research groups investigating the various applications of this reaction medium and most studies have focused on solvents derived from the imidazolium cation. The use of the imidazolium-based ILs in the Diels-Alder reaction has been studied in detail and higher yields compared to conventional methods have been reported. The IL affects the rate and interesting selectivities have been observed. However, not much attention has been paid to the scope and limitations of phosphonium ILs (PILs). Therefore the focus of this thesis is the synthesis and application of novel chiral PILs as environmentally benign, task-specific solvents for the Diels-Alder reaction. In addition, this research seeks alternative ways to eliminate the use of toxic heavy metal catalysts and to exploit methodologies which reduce the energy consumption of the Diels-Alder reaction. A series of CILs were synthesised from the chiral pool and they were characterised by thermogravimetric analysis, differential scanning calorimetry and spectroscopy. They were then investigated as solvents and catalysts in the Diels-Alder reactions of a series of dienes (cyclopentadiene, isoprene, 2,3-dimethylbuta-1,3-diene, furan, pyrrole, N-methyl pyrrole) and dienophiles (methyl acrylate, methyl vinyl ketone, acrylonitrile, dimethyl maleate, acrolein, dimethylacetylene dicarboxylate, maleic anhydride and maleimide). Investigation of the effect of PILs in the presence of three heterogeneous catalysts Al2O3, SiO2 and K-10 montmorillonite were studied. Ultrasound and microwave-assisted Diels-Alder reactions in the PILs, in the absence and presence of the catalysts, were also studied. The reactions of these prototypical substrates illustrated that the solvents are indeed task-specific.

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7

Newbury, Daniel John. "Part A: Progress Towards the Total Synthesis of (±)-Communesin F; Part B: Aluminum as a Catalyst for the Diels-Alder Cycloaddition of Highly Hindered Dienophiles." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23943.

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This is a thesis in two parts. Part A examines two potential routes towards the synthesis of the communesin family of alkaloids, as well as an overview of some of the successful synthetic routes to date. Our first proposed route involves the gold catalyzed isomerization of an o-amino aryallene to a vinyl imine and subsequent (formal) cycloaddition with an indole. This would have allowed quick access to the pentacyclic core of the communesins; however, the unexpected 5-endo-dig product was exclusively obtained in good to excellent yields. The second route involves the use of a Meerwein- Eschenmoser Claisen rearrangement. This route was successful in affording the C, D, E and F rings of the communesin alkaloids, however future work is required for completion of the synthesis. Also discussed in these sections is an alternative endgame approach involving a novel Pictet-Spangler reaction to afford the G ring, and the possibility of an asymmetric variation to the proposed route. Part B examines the use of alkyl aluminum sesquichlorides in the catalysis of Diels-Alder cycloadditions of sterically hindered systems, a current obstacle in organic chemistry. Previously developed methods are discussed and preliminary results are presented. Ethyl aluminum sesquichloride is compared to other alkyl aluminum catalyst, and the effects of temperature, catalysts loading, choice of solvent, the use of additives, and the use of chiral oxazolidinones are reported and what these result can tell us about the mechanism of catalysis are discussed.

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CHAPTAL-GRADOZ, NATHALIE. "Regio et stereoselectivite de reactions de diels-alder entre des dienes portant un substituant allylique chiral en position deux et divers dienophiles. Applications." Paris 11, 1993. http://www.theses.fr/1993PA112310.

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L'etude de la regio et de la diastereoselectivite de la cycloaddition entre des dienes substitues en position 2 par un substituant allylique chiral et divers dienophiles a constitue l'essentiel de ce travail. Si la regioselectivite des reactions thermiques ou realisees dans un milieu concentre en perchlorate de lithium n'est que moyenne en faveur du produit para disubstitue, celle-ci devient totale dans la reaction catalysee par un acide de lewis. La diastereoselectivite faciale augmente, quant a elle, avec l'encombrement sterique du groupe r porte par le diene et est inversee selon que l'on utilise des dienes a fonction hydroxyle libre ou protegee. Les cycloadditions catalysees ne sont possibles qu'avec des dienes proteges mais la reaction est alors regiospecifique et tres hautement diastereoselective. En nous basant sur les donnees de la litterature, nous avons propose des modeles d'etats de transition rendant compte de la plupart des faits experimentaux. Par ailleurs, nous avons determine par modelisation moleculaire les conformeres privilegies des dienes etudies et modelise ces memes etats de transition. Il ressort que la difference de comportement des dienes a fonction hydroxyle libre ou protegee repose vraisemblablement sur l'existence ou non d'une liaison hydrogene entre le diene et le dienophile dans l'etat de transition. Des experiences de dedoublement enzymatique de melanges racemiques des dienes de depart ont ete realisees. Par transesterifications en presence de lipase au depart de dienes a fonction hydroxyle libre d'une part ou par hydrolyse d'esters derives de ces memes dienes d'autre part, des exces enantiomeriques de l'ordre de 70 a 80% ont ainsi pu etre obtenus. Enfin, le transfert de chiralite sur le cycle des adduits a l'aide de reactions diastereoselectives a ete etudie. La selectivite des divers processus reflete essentiellement la competition entre les deux conformeres du compose de depart et s'etablit generalement autour de 80 contre 20 en faveur du produit a geometrie de double liaison

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9

Byeon, Chang-Ho. "Part I. Reactions of alpha,beta-unsaturated thioesters and selenoesters with enamines :Part II. Alpha,beta-unsaturated thioesters and selenoesters as dienophiles :Synthesis of cyclohexene derivatives /." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487856076418125.

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10

Perkins, Jonathan Clarence. "Synthesis of [2.2.2]-Diazabicyclic Alkaloids: I: Diels-Alder Reactions of a C2-Carboxy Pyrazinone & Ii: Intermolecular Diels-Alder Reaction of a Proline Derived Pyrazinone with Symmetric Dienophiles." W&M ScholarWorks, 2017. https://scholarworks.wm.edu/etd/1516639679.

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[2.2.2]-Diazabicyclic alkaloids are a natural product family with diverse biological activities. The development of a synthetic methods towards the synthesis of [2.2.2]-diazabicyclic alkaloids is described. I: Diels-Alder Reactions of a C2-Carboxy Pyrazinone Using an N-heterocyclic carbene catalyzed aroylation of a proline 3,5-dichloropyrazinone, a synthetic route to C2-carboxy pyrazinones was developed to study the intermolecular and intramolecular Diels-Alder reactions of these compounds to form the bicyclo[2.2.2]diazaoctane core. Studies showed that having oxidation present α to the pyrazinone ring did not provide any significant increase in reactivity or selectivity as compared to pyrazinones without oxidation α to the ring. In some cases, the oxidation completely hindered reactivity. II: Intermolecular Diels-Alder Reaction of a Proline Derived Pyrazinone with Symmetric Dienophiles The intermolecular Diels-Alder reaction of a proline derived pyrazinone with maleic anhydride allows for selective access the anti-C19 isomer of the [2.2.2]-diazabicylic alkaloid. Selective opening of the resulting anhydride cycloadduct followed by radical excision of the C18 carboxy group provides a known intermediate in the Williams’ synthesis of Brevianamide B. The overall route provides the desired anti-C19 isomer of the methyl ester product in 6 steps and 12% overall yield from the proline derived pyrazinone. This route constitutes a 15 step formal synthesis of Brevianamide B.

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11

McAllister, Graeme Douglas. "Development of an assay for a Diels-Alderase enzyme." Thesis, University of Glasgow, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312729.

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12

Clapham, Gary. "New Lewis acid promoted Diels-Alder reaction and transition catalysed hydrocarbons." Thesis, University of Exeter, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284618.

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13

Allen, Damian Arthur. "Facile synthesis of cis-2-alkyl-3-trialkylsilyloxycycloalkanones via the non-aldol aldol rearrangement of 2,3-epoxycycloalkanols ; and, Use of 4-cyanocoumarins as dienophiles in a facile synthesis of highly substituted dibenzopyranones ; and, Progress toward the total synthesis of N-methylwelwitindolinone C isothiocyanate." Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1997737701&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.

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Smith, Sharon. "Studies of thioaldehydes and dienophilic dithioesters." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296966.

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15

Dentel, Hélène. "Réactions asymétriques d'hétéro Diels-Alder impliquant un dienophile dithioester." Caen, 2011. http://www.theses.fr/2011CAEN2048.

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L’objectif du projet a été de développer des versions asymétriques de la réaction d’hétéro-Diels-Alder (HDA) à partir de dithioesters. Les réactions diastéréosélectives entre des dithioesters portant des auxiliaires chiraux alcool ou oxazolidinone et le 2,3-diméthyl-1,3-butadiène ont conduit à des excès diastéréomériques allant jusqu’à 78%. En version énantiosélective, le meilleur résultat (82% ee) a été obtenu à partir du dithiooxalate d’éthyle et du 2,3-diméthyl-1,3-butadiène, en présence de 5 mol% d’un catalyseur chiral Cu(OTf)2/bis(oxazoline). La réaction est limitée car fortement substrat-dépendante, mais représente le premier exemple d’une réaction d’HDA catalytique énantiosélective, à partir d’un diénophile thiocarbonylé. Pour chaque cycloadduit, la stéréochimie absolue a été détérminée par corrélation structurale à partir d’un dérivé analysé par RX. Des expériences de double différentiation (dithioester chiral/catalyseur chiral) ont été réalisées. Pour un dithiooxalate, le sens de l’induction asymétrique semble être guidé par le catalyseur, alors que pour un dithioester oxazolidinone, le catalyseur influence peu l’énantiosélectivité, dû probablement aux différentes possibilités de coordination (O,O vs S,O) du diénophile à l’acide de Lewis. Pour rationaliser les résultats, nous avons proposé une géométrie tétraédrique du complexe dithiooxalate/catalyseur (avec chélation S,O du cuivre) et plan-carrée pour celui impliquant l’oxazolidinone dithioester (avec chélation O,O du cuivre). L’étude théorique de la réaction a montré qu’un catalyseur chiral peut accélérer la cycloaddition et induire l’asymétrie, les dithioesters étudiés étant coordinés au métal de façon bidentée
The project was focused on the development of asymmetric hetero-Diels-Alder (HDA) reactions involving dithioester as dienophiles. The cycloadditions between dithioesters bearing an alcohol or an oxazolidinone as a chiral auxiliary and 2,3-dimethyl-1,3-butadiene led to diastereomeric excess up to 78%. In the enantioselective version, the best result (82% ee) was obtained with ethyl dithiooxalate and 2,3-dimethyl-1,3-butadiene in the presence of a chiral Cu(OTf)2/bis(oxazoline) complex. The enantioselectivity seems to be substrates/catalyst dependent yielding to difficult control. Even if this reaction is limited for synthetic applications, it represents the first example of a catalytic asymmetric HDA reaction with a chiral Lewis acid as activator of the thiocarbonyl partner. The absolute stereochemistry of each cycloadduct was assigned by structural correlation with a derivative analyzed by X-Ray. Double-stereodifferentiating experiments (chiral dithioester/chiral catalyst) have shown that the asymmetric induction is mainly controlled by the catalyst when dithiooxalate was involved. When an oxazolidinone dithioester was employed, the catalyst poorly influences the enantioselectivity, probably due to the different possible chelation modes between the dienophile and the Lewis acid (O,O vs S,O). To rationalize these results, we assume a tetrahedral geometry of the dithiooxalate/catalyst complex (S,O copper chelation) and a square-planar geometry with the oxazolidinone dithioester (O,O copper chelation). The theoretical study indicated that a chiral catalyst could accelerate the cycloaddition and induce asymmetry, with a bidentate chelation of the dithioesters to the metal

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Schumann, Patrick Reiner. "Diastereomere Makrocyclen auf Basis von Bistriazol-Dienophilen und Sorbyl- und Sorboyl-Derivaten." Doctoral thesis, Universitätsbibliothek Chemnitz, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200800489.

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Gegenstand der vorliegenden Arbeit ist die Untersuchung makrocyclischer Strukturen, welche über eine Sequenz von zwei Diels-Alder-Reaktionen synthetisiert wurden. Dabei wurden leichtzugängliche Sorbinsäure- und Sorbyl-Abkömmlinge mit aliphatisch-verknüpften Bis-(1,2,4-triazolin-3,5-dionen) kombiniert. Infolge der Prochiralität der eingesetzten Bisdiene können stereochemisch-differenzierte Reaktionsprodukte auftreten. Besonderes Augenmerk lag auf der stereochemischen Zuordnung, welche in vielen Fällen mittels NMR-Spektroskopie oder Einkristall-Röntgenstrukturanalyse gelang.

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Guo, Zijian. "Developing unstrained alkenes and alkynes for bioorthogonal chemistry." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/289423.

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Bioorthogonal reactions, due to its excellent selectivity and time-efficiency, have emerged as a popular tool for protein and cell probing. Among all the bioorthogonal reactions, the inverse electron-demand Diels-Alder reaction (IEDDA) reaction has its advantage of bearing the fastest kinetics. Although the IEDDA reaction drew considerable attention in chemical biology in the last decade, challenges lie in finding the suitable dienophiles. Strained dienophiles, for example, trans-cyclooctene derivatives, can undergo ultrafast IEDDA reactions and therefore have been extensively developed. Unstrained alkenes and alkynes, however, have not been well investigated as IEDDA handles. In general, unstrained dienophiles are more straightforward to synthesise compared with strained dienophiles, therefore they are more accessible to researchers. In addition, the absence of a highly reactive bond makes unstrained dienophiles inert to biological nucleophiles, which allows effectively cellular labelling. In this dissertation, I described three different unstrained dienophiles for different biological purposes. Allyl handle is thiol-stable and non-toxic, which was utilised to label apoptotic cells in a pre-targeting manner. Enol ethers can react with tetrazines to decage protected amino acids and prodrugs. Potassium arylethynyltrifluoroborate, as a novel dienophile, was shown to react fast with pyridyl tetrazines controllably and this new IEDDA was applied to label proteins site-selectively and to fluorescently label two proteins orthogonally. In addition to IEDDA reactions, other bioorthogonal reactions were also developed using these versatile unstrained handles. Allyl-bearing amino acids and proteins can undergo an acetophenone-mediated hetero-[2+2] photocycloaddition with maleimide derivatives, expanding the toolbox of photo-triggered chemistry for protein modification. The potassium arylethynyltrifluoroborate handle was also found reactive in copper(I)-catalyzed alkyne-azide cycloaddition reaction (CuAAC) and showcased the huge potential for protein labelling and multicolour cellular labelling.

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18

Essers, Michael. "Diels-Alder-Reaktionen fluorierter Dienophile und Diene und ihr Einsatz in Synthesen fluorierter Steroidanaloga und Cantharidine." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=966627504.

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19

Shah, Saral. "SOLUTION PROCESSIBLE AROMATIC POLYIMIDES VIA DIELS ALDER PRECURSOR." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3509.

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Aromatic polyimides are interesting materials since they possess outstanding key properties such as thermoxidative stability, high mechanical strength, high modulus, excellent electrical properties, and superior chemical resistance. However, their low solubility makes them difficult to characterize, process and obtain high molecular weight polymer. In this report, we synthesized a series of precursor polymers that contains Diels-Alder (DA) adducts of anthracene. Different dienophiles were tried. These precursor polymers are soluble in common organic solvents such as chloroform and can be easily processed to thin films. Heating the film above 215 degree induce retro-DA reaction, which generated the fully aromatic polyimides in situ. The solid-state retro-DA reactions were monitored by ATR-FTIR and UV-Vis spectra. The fully aromatic polyimides are highly stable and their thin films are insoluble in organic solvents. Profilometry and AFM studies showed that after the thermal treatment, the films are smooth and pin-hole free, while the volumes decreased with a percentage close to the weight loss caused by retro-DA reaction. These Polymers can have a wide range of potential applications from thermal patterning polymers to organic photovoltaics.
M.S.
Department of Chemistry
Sciences
Industrial Chemistry MS

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20

Hickey, Eugene R. "Pi - facially nonequivalent cyclopentadienes : experimental and theoretical evaluation of the stereochemistry of dienophilic capture /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487848078448276.

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21

Chopin, Nathalie. "Etude de la dienophilie des benzofurannes et indoles. Application à la synthèse d’analogues de la galanthamine." Rouen, 2008. http://www.theses.fr/2008ROUES017.

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La réaction de Diels-Alder fait partie des moyens convergents pour assembler des hétérocycles de façon efficace et stéréosélective. Du fait de leur caractère aromatique riche en électrons, les benzofurannes et les indoles sont rarement utilisés en tant que diénophiles en réaction de cycloaddition [4+2] à demande électronique normale. Néanmoins, nous avons montré que, si les substrats benzofuranniques étaient correctement substitués par un groupement électroattracteur en position 3, la réaction conduit à un cycloadduit tricyclique désaromatisé portant un carbone quaternaire en jonction de cycle et une stéréochimie cis. Cet intermédiaire synthétique oxygéné présente un motif structural commun aux alcaloïdes d’Opiacées et d’Amaryllidacées, notamment la galanthamine utilisée actuellement dans le cadre du traitement de la maladie d’Alzheimer. Dans le but de mettre au point cette méthodologie de synthèse, différentes substitutions du noyau aromatique et plusieurs méthodes d’activation de la réaction de Diels-Alder, thermique, hyperbare et/ou acidocatalysées, ont été expérimentées. Le développement de cette méthodologie permet à présent d’envisager la suite de la synthèse totale de la galanthamine. Son analogue azoté, l’azagalanthamine, pourrait être accessible de manière analogue en utilisant une réaction de Diels-Alder à partir d’indoles. Dans ce contexte, nous avons envisagé une réaction intramoléculaire et avons optimisé les substituants des parties diénique et diénophilique. Les cycloadduits tétracycliques cibles sont des analogues de la cétone de Büchi, intermédiaire-clé dans la synthèse d’alcaloïdes de type Aspidosperma et Strychnos
The Diels-Alder approach is a very convergent way of assembling heterocycles rapidly and stereoselectively. Because of their aromaticity, the electron-rich benzofurans and indoles have not been used very often as dienophiles in normal electron demand [4+2] cycloaddition. We have shown that, when properly substituted by electron withdrawing group in position 3, benzofurans can lead to desaromatised tricyclic cycloadducts featuring a quaternary carbon at ring junction and a cis stereochemistry. These oxygenated skeletons possess a framework common to Opium and Amaryllidaceae alkaloids, galanthamine, used in Alzheimer’s disease treatment, has been selected as a potential molecular target for the application of this approach. In order to develop this synthetic methodology, the influence of various substituents on the aromatic benzofuran ring was studied as well as the activation mode, thermal, hyperbaric and/or by Lewis acid. The cycloaddition reaction was optimized and the results gathered so far allow to envision total synthesis of galanthamine. The possibility of reaching the nitrogenated analogue azagalanthamine throught a similar approach using indoles was also considered. An intramolecular cycloaddition was envisaged and optimization of the synthesis of several substrates was carried out. The target tetracyclic adducts are similar to Büchi’s ketone, a key intermediate in the preparation Aspidosperma and Strychnos alkaloids

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Steizer, Lindsay S. "Synthesis of polysubstituted pyridines : Diels-Alder addition of 1-AZA-1, 3-dienes with acetylenic and ethylenic dienophil." Virtual Press, 1986. http://liblink.bsu.edu/uhtbin/catkey/452401.

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The synthesis of methyl 3,6-dimethylpyridine-2-carboxylate (192) by the Diels-Alder addition of 3-butene-2-one dimethylhydrazone (190) and methyl-2-butynoate (16) is described. The structure of 192 was confirmed by the synthesis of methyl 2,6-dimethylpyridine-3-carboxylate (195), the opposite regioisomer.The synthesis of methyl 3,5-dimethylpyridine-2-carboxylate (199) from [4+2] cycloaddition of 2-methyl-2-propenal dimethylhydrazone (171) and 16 is described. In addition to producing a small amount of 199 directly, the reaction produced an intermediate of possible structure 198 which yielded 199 on catalytic dehydrogenation.On prolonged heating, 2-acetyl-5-methylpyridine (200) was produced by the reaction of diene 171 with methyl vinyl ketone (176).The preparation of 2-cyan-5-methylpyridine (201) from the tetrahydropyridine derivative 175 via catalytic dehydrogenation is described.The synthesis of 5,7-dioxo-3-methyl-6-phenyl-1,1.,5,6,7-pentahydropyrroloC3,1.-b] pyridine (202) through the Diels-Alder addition of diene 171 and N-phenylmaleimide (149) is described. Also reported is the preparation of 5,7-dioxo-3-methyl-6-phenyl-3,5,6-trihydropyrrolo [3,1+-b]pyridine (203) via dehydrogenation of 202.
Department of Chemistry

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23

Goussé, Cécile. "Applications de la réaction de Diels-Alder aux polymères furaniques." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0007.

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Certains derives furaniques, obtenus a partir de la biomasse, se comportent comme d'excellents dienes vis a vis de la reaction de diels-alder. Dans cette perspective, l'application de cette reaction aux polymeres furaniques peut etre envisagee sous deux aspects. Le premier consiste en la modification de polymeres tels l'alcool polyvinylique ou le polystyrene par greffage de groupements pendants furaniques, qui seront ensuite mis en reaction avec des mono ou bismaleimides conduisant respectivement a des polyadduits ou des gels. Le second concerne la synthese et la polycondensation de monomeres possedant des extremites dieniques et/ou dienophile (aa + bb et ab). Cette these decrit l'elaboration et la caracterisation de divers materiaux bases sur l'application de ces differents concepts. La reversibilite de la reaction de diels-alder sur ce type de composes a egalement ete etudiee.

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Sancibrao, Pierre. "Cycloadditions de nitroso Diels-Alder asymétriques et régiosélectives : une nouvelle voie synthétique d'hétérospirocycles." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112417.

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Au cours de ce projet de recherche, nous nous sommes intéressés à la synthèse de motifs hétérospiraniques énantioenrichis. De ce fait, notre équipe a pu élaborer une nouvelle voie synthétique pouvant conduire à la synthèse de molécules possédant des structures bicycliques spiraniques diverses. Cette voie de synthèse inédite est articulée sur une réaction de nitroso Diels-Alder. Le contrôle de la stéréosélectivité ainsi que le contrôle de la régiosélectivité, peu décrit dans la littérature, ont été spécifiquement étudiés lors de ces travaux. Nos différentes études ont permis de mieux appréhender ces aspects de la réaction de nitroso Diels-Alder. Deux approches différentes ont d’ailleurs été développées au cours de ces travaux. Celles-ci ont toutes deux conduit a un contrôle total de la régiosélectivité de cette cycloaddition. Les cycloadditions réalisées par une réaction utilisant un diénophile de type nitrosopyridine et catalysées par une source de cuivre chiral ont conduit aux cycloadduits précurseurs d’azaspirobicycles avec une énantiosélectivité modeste. D’autres cycloadditions utilisant un dienophile chiral de type chloronitroso dérivé du D-xylose ont permis la synthèse de précurseurs de bicycles oxaspiraniques avec des excès énantiomériques supérieurs à 95%. Cette dernière approche a permis la synthèse de spiroethers par une réaction d’ouverture de liaison N-O ainsi qu’une réaction de substitution nucléophile intramoléculaire, tandis que des spirolactones ont été obtenus par oxydation du diol résultant de l’ouverture de la liaison N-O. La fonctionnalisation de ces structures a été possible en engageant leur fonction vinyl triflate dans des couplages de Suzuki. Il a ainsi été possible de synthétiser 9 structures différentes oaxaspiraniques dont 5 de façons énantiosélectives
During this research, we were interested in the synthesis of enantiopur heterospiranic bicycles. We therefore developed a new synthetic route towards the synthesis of molecules with different spirocyclic structures. This novel synthetic route features a nitroso Diels-Alder cycloaddition as key step. The total control of the stereoselectivity and the regioselectivity of the reaction, rarely described in the literature, have been specifically studied during this work. This study allows us to have a better understanding of this reaction. Two different approaches have been developed in this work. They both led to total control of the regioselectivity of this cycloaddition. Cycloadditions performed by reactions using a nitrosopyridine dienophile and catalyzed by a chiral source of copper allows the synthesis of cycloadducts precursor of azaspirocycles with a modest enantioselectivity. Cycloadditions using a chloronitroso chiral dienophile derived from xylose allowed the synthesis of oxaspiraniques precursors with enantioselective excess of at least 95%. The last approach was finally validated by the synthesis of various spiroethers and spirolactones through N-O bond cleavage an intramolecular cyclizations. Finally, the vinyl triflate function of the spirolactones and spiroethers was engaged in Suzuki couplings to introduce molecular diversity at a late stage allowing the synthesis of 9 different spiranic structures including 5 enantioenriched

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25

Dorset, Rachel Ruth. "Cationic Diels-Alder dienophiles stablized by cobalt-complexed alkynes." 2010. http://hdl.handle.net/10090/15130.

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Guo, Peng. "New chiral dienophiles and their reactions with ortho-quinodimethanes." 1992. http://hdl.handle.net/1993/18027.

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(14010168), Mirta Golic. "The preparation of dienes and dienophiles containing nucleic acid bases." Thesis, 1999. https://figshare.com/articles/thesis/The_preparation_of_dienes_and_dienophiles_containing_nucleic_acid_bases/21397758.

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The work presented in this thesis deals initially with the synthesis of rigid polyalicyclic dienes and dienophiles with pyrimidine moieties inbuilt in a rigid fashion (building BLOCKS). This work has allowed the production of a new class of ribbon molecules with precisely defined size, shape and position of the pyrimidine ring. In the second stage of the project, an assessment of their ability to participate in cycloaddition reactions as pyrimidine building BLOCK* components was investigated.

2,4-Dimethoxy-1,3-diazaanthracene (I) has acted as the pyrimidine transfer reagent for preparing building BLOCKs. The Diels-Alder adducts IV and V (Scheme I), prepared by reaction of I with norbomadiene, are new pyrimidine dienophilic BLOCKs. Both I and 2,4-dichloro-1,3-diazaanthracene (II) were active in photochemical [4π+4π] cycloaddition reactions with cyclopentadiene to form a second class of building BLOCKs VII and VIII (Scheme I). In addition, the photodimerisation of I and II was studied and structures IX-XII assigned on the basis of spectral and X-ray method.

The 2,4-dichloro-photoadduct VIII is of particular importance for this work since it is easily hydrolysed (2M NaOH, 60 °C, overnight) to the corresponding uracil XIII In contrast, thermal adducts IV and V were very difficult to hydrolyse (NaOH fusion) to uracils XIV and XV (Figure I).

The availability of pyrimidine BLOCKs which contain a reactive π-bond, e.g. (IV, V, VII and VIII) has enabled us to employ 3,6-di(2'-pyridyl)-s-tetrazine (XVI) and ACE (Alkene plus Cyclobutene Epoxide) coupling methods to obtain precisely functionalised ribbon molecules in a direct, convergent synthetic strategy.

The synthesis of the bis-pyrimidines by coupling norbornene reagents using 3,6-di(2'-pyridyl)-s-tetrazine is illustrated in Scheme II. In the first step, s-tetrazine XVI was reacted with pyrimidine BLOCK V under basic conditions to generate the dihydropyridazine XVII. This diaza-1,3-diene was reacted with a further equivalent of V under high pressure conditions to yield the bis-pyrimidines XVIII and XIX, which were separated by radial chromatography. The same procedure was used to link pyrimiclines to other effectors by using alternative alkenes in the second step.

The ACE coupling protocol is illustrated by the reaction of alkene VIII with the dimethoxynaphthalene-containing epoxide XX (Scheme III). The reaction can be conducted under thermal or photochemical conditions and is considered to proceed via 1,3-dipolar intermediate formed by ring-opening of the epoxide C-C bond of XX (See Chapter 4).

Each class of coupled adduct could be hydrolysed to the corresponding uracil by using either acid (XXII) or base (XXIII) hydrolysis conditions, the choice depending on the structure of the molecule in question and its substituents.

The work presented in this thesis involves a deal of new work and has been instrumental in the development of the Lego^®-based BLOCK assembly protocol for ribbon molecules construction.

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Deng, Zong-Fan, and 鄧宗凡. "The study of chiral sulfinyl dienophiles in asymmetrical Diels-Alder reactions." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/80821991665714901972.

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Gao, Shih-Yu, and 高世育. "Highly regio- and stereocontrolled Diels-Alder reactions of masked o-benzoquinones with electron-rich dienophiles." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/91107565292952708613.

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碩士
國立清華大學
化學系
88
The studies on the Diels-Alder reactions of masked o-benzoquinones (MOBs) 50 with electron-rich dienophiles and synthetic applications of Diels-Alder cycloadducts 56a-e are described. This thesis deals with the Diels-Alder reactions of MOBs with electron-rich dienophiles and the synthesis of bicyclo[2.2.2]octadienone derivatives. Diels-Alder reactions of MOBs 50 with four electron-rich dieno- philes namely, benzyl vinyl ether, 2,3-dihydrofuran, 3,4-dihydropyran and phenyl vinyl sulfide and a conjugated dienophile styrene afforded highly functionalized bicyclo[2.2.2]octenones 51a-g, 54a-g, 55a, 56a-g and 57a-h in high regio- and stereoselectivities. Based on RHF/3-21G* calculations, it is suggested that LUMO of MOBs and HOMO of benzyl vinyl ether, 2,3-dihydrofuran and styrene are involved in the inverse electron-demand Diels-Alder reactions. We have carried out the oxidation of Diels-Alder cycloadducts 56a-e derived from MOBs and phenyl vinyl sulfide with m-CPBA at -78 ℃ to produce the corresponding sulfoxides 63a-e in high yields. The sulfo- xides 63a-e at reflux temperature in mesitylene furnished bicyclo[2.2.2]- octa-2,5-dien-1-ones 64a-e in very good yields. The compounds 64a-e are immediate precursors for heteroaromatic-fused barrelenes, which are very useful starting materials for the photochemical rearrangements.

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CHEN, QING-RONG, and 陳慶榮. "Applications of MerCO and its derivatives, (III) new chiral ��-sulfinyl dienophiles for asymmetric Dies-Alder reations." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/58203422026986292354.

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山田, 浩貴, and Hiroki Yamada. "Enantioselective Diels–Alder Reaction Catalyzed by Chiral Ammonium Salts: The Synthetic Applications and the Design of New Dienophiles." Thesis, 2014. http://hdl.handle.net/2237/20271.

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Afarinkia, Kamyar, M. J. Bearpark, and A. Ndibwami. "A Computational and Experimental Investigation of the Diels-Alder Cycloadditions of Halogen Substituted 2(H)-pyran-2-one." 2003. http://hdl.handle.net/10454/2366.

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No
4-Chloro-2(H)-pyran-2-one undergoes thermal Diels−Alder cycloaddition with electron-deficient dienophiles to afford, without any significant selectivity, 6-endo- and 5-endo-substituted bicyclic lactone cycloadducts. In contrast to 3- and 5-bromo-2(H)-pyran-2-one, 4-chloro-2(H)-pyran-2-one does not undergo thermal cycloadditions with electron-rich dienophiles. The regio- and stereochemical preferences of the cycloadditions of 4-chloro-2(H)-pyran-2-one and other related 2(H)-pyran-2-ones are investigated computationally. Calculations were carried out on the transition states leading to the four possible regio- and stereoisomeric cycloadducts using density functional theory (B3LYP/6-31G*). These studies allow prediction of the regio- and stereoselectivity in these reactions which are in line with experimental observations.

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33

Pottie, Ian R. "Exploration of the inverse-electron-demand Diels-Alder (IEDDA) reaction. Rapid access to benzocoumarins via IEDDA-driven domino reactions of coumarin-fused electron-deficient dienes with electron-rich dienophiles /." 2002.

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Aldrin, Stephanie Vivian. "The Diels-Alder reaction synthesis of a cationic dienophile /." 2010. http://hdl.handle.net/10090/15119.

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Richter, Frank [Verfasser]. "Intramolekulare Diels-Alder-Reaktionen mit sauerstoffhaltigen cyclischen Dienophilen / vorgelegt von Frank Richter." 2002. http://d-nb.info/974165050/34.

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Chang, Yan-Long, and 張言隆. "Effects of High Pressure on the Photosensitized Diels-Alder Reactions of Electron-rich Dienophile." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/03859899152176649430.

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Latta, Paul Richard. "Synthesis of diene and dienophile substrates for in-vitro selection of RNA-hetero-diels-alder catalysts." 2004. http://www.lib.ncsu.edu/theses/available/etd-04292005-132210/unrestricted/etd.pdf.

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Schumann, Patrick Reiner [Verfasser]. "Diastereomere Makrocyclen auf Basis von Bistriazol-Dienophilen und Sorbyl- und Sorboyl-Derivaten / vorgelegt von Patrick Reiner Schumann." 2008. http://d-nb.info/989724417/34.

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Essers, Michael [Verfasser]. "Diels-Alder-Reaktionen fluorierter Dienophile und Diene und ihr Einsatz in Synthesen fluorierter Steroidanaloga und Cantharidine / Michael Essers." 2001. http://d-nb.info/966627504/34.

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40

Lording, William James. "A deeper understanding of the Diels–Alder reaction." Phd thesis, 2010. http://hdl.handle.net/1885/11776.

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The Diels-Alder reaction was discovered in 1928 and has become the most efficient and practical method for the synthesis of six-membered carbocyclic and heterocyclic rings. This thesis comprises three chapters of results and discussion with the Diels-Alder reaction as a theme. Chapter 2 details an investigation of endo:exo selectivity in the Diels-Alder reactions of 1,3-butadiene. Chapter 3 explores aspects of the intramolecular Diels-Alder reactions of some substituted 1,3,8-nonatrienes, and Chapter 4 describes the domino Diels-Alder reactions of 1,4-diiodo-1,3-butadiene. The Diels-Alder reaction is powerful, general, and widely used in chemical synthesis, and it is well known that many Diels-Alder reactions exhibit endo selectivity, in accord with Alder’s empirical rule. The origins of endo:exo selectivity in the Diels-Alder reaction, however, are not completely understood and there is a dearth of experimental evidence concerning the Diels-Alder reactions of the archetypal 1,3-diene, 1,3- butadiene. Chapter 2 describes a study of the Diels-Alder reactions of an isotopically labelled 1,3-butadiene with a range of simple dienophiles, allowing the endo:exo selectivities of these important reactions to be determined for the first time. The experimental data shed light on the origins of endo:exo selectivity in the Diels-Alder reaction and will serve as an important reference for future computational investigations in this area. The intramolecular Diels-Alder reaction shares many of the virtues of its intermolecular counterpart, however its use in chemical synthesis is limited because intramolecular Diels-Alder reactivity and stereoselectivity are often governed by subtle factors, and can be very difficult to predict. As part of a comprehensive experimental and computational collaboration, Chapter 3 describes an investigation of the heat and Lewis acid promoted intramolecular Diels-Alder reactions of some ether tethered 1,3,8-nonatrienes. Also presented are the results of a rate study and a kinetic isotope effect study involving the intramolecular Diels-Alder reactions of some 1,3,8-nonatrienes. The experimental data are analysed and compared with predicted stereoselectivities, activation barriers and kinetic isotope effects obtained from computational modelling. Increased efficiency in chemical synthesis conserves resources, reduces waste, and saves time and money. Domino reactions are particularly efficient processes, which can generate complex products from simple reactants. Chapter 4 describes an investigation of the domino Diels-Alder reactions of (1E,3E)-1,4-diiodo-1,3-butadiene with maleimide dienophiles, through which a family of bicyclo[2.2.2]oct-2-ene derivatives are produced in one high yielding and stereoselective synthetic step.

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Dissertations / Theses on the topic 'Dienophiles'

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