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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Στατιστική ανάλυση σχέσης δομής δράσης πουρινικών και οξινδολικών παραγώγων

Κουστένης, Αθανάσιος 06 December 2013 (has links)
Σκοπός της παρούσης εργασίας είναι η στατιστική ανάλυση της σχέσης δομής-δράσης των χημικών ενώσεων που παράγονται από οξινδόλια και πουρίνες πάνω στα σύμπλοκα CDKs/Cyclins και η εξαγωγή συμπερασμάτων πάνω στις σχέσεις αυτές. Για το σκοπό αυτό ανατρέξαμε στην διεθνή βιβλιογραφία για να συλλέξουμε όσες πληροφορίες έχουν δημοσιευτεί έως τώρα για τις δύο αυτές ομάδες ενώσεων. Έπειτα μέσω ειδικών προγραμμάτων έγινε η επεξεργασία τους και η ανάλυση τους. Σκοπός είναι να συσχετίσουμε τη δομή των ενώσεων αυτών με τη δράση και τη βιολογική τους απόκριση πάνω στα σύμπλοκα των CDKs με τις κυκλίνες. / -
2

New Methods for the Synthesis of Vicinal Stereocenters : Palladium-Catalyzed Domino Reactions and Asymmetric Transfer Hydrogenation

Seashore-Ludlow, Brinton January 2012 (has links)
In this thesis the synthesis of vicinal stereocenters is investigated in two distinct contexts, namely the construction of 3,3-disubstituted oxindoles and the synthesis of b-hydroxy-a-amino acids. Both scaffolds are prevalent in a range of natural products and biologically relevant compounds and, therefore, methods for their synthesis are of great import. First, the construction of 3,3-disubstituted oxindoles using palladium-catalyzed domino reactions is described.  This covers two stereospecific methods for the construction of the desired oxindoles based on domino carbopalladation sequences.  The termination events for these domino reactions are carbonylation or cross-coupling.  In the carbopalladation-carbonylation reaction, we studied the possibilty of suppressing b-hydride elimination for substrates possessing pendant b-hydrogens.  In the carbopalladation-cross-coupling sequence, we examined the role of the boron source and substrate scaffold in the outcome of the reaction.  In both of these methods, an intricate balance of rates needs to be attained in order to achieve the desired domino sequences.  Thus, these investigations offer insight into the rates of the competing reactions, and the factors that influence these processes. Secondly, the stereoselective synthesis of b-hydroxy-a-amino acids is explored.  This has lead to two separate methods for the construction of this scaffold.  We first examined a 1,3-dipolar cycloaddition of azomethine ylides to aldehydes for the construction of syn-b-hydroxy-a-amino esters.  It was found that one set of azomethine ylides reacted through a 1,3-dipolar cycloaddition, while the other set reacted via a direct aldol reaction.  Finally, we studied an asymmetric transfer hydrogenation reaction to provide anti-b-hydroxy-a-amido esters from the corresponding a-amido-b-ketoesters.  Two protocols were developed for the reduction of these substrates, one using triethylammonium formate and the other using sodium formate in an emulsion.  The latter method gives high yields, diastereoselectivities and enantioselectivities for a broad range of substrates. / QC 20120605
3

Synthesis of 3,3-disubstituted 2-oxindoles by deacylative alkylation and photocatalytic alkylation of olefins by zinc-sulfinates

Ortega-Martínez, Aitor 13 March 2018 (has links)
La tesis doctoral está dividida en una introducción general y cuatro capítulos. En la introducción general, se describen diferentes productos naturales y derivados sintéticos que contienen un núcleo de oxindol en su estructura junto a comentarios sobre sus actividades biológicas. Además, también están incluidas diversas metodologías de síntesis para la síntesis de estos derivados de oxindol junto a una explicación general sobre el proceso de alquilación desacetilativa. Los capítulos se han desarrollado con una breve introducción, una propuesta de objetivos, comentarios y discusión de los resultados obtenidos en las investigaciones finalizando con las conclusiones obtenidas. El Capítulo 1 trata sobre la síntesis de 2-oxindoles 3,3-disustitutidos a través de un proceso de alquilación desacetilativa utilizando halogenuros de alquilo. El Capítulo 2 describe la alilación y la alilación desacetilativa catalizada por paladio de los derivados de 2-oxindol utilizando alcoholes alílicos no activados. En el Capítulo 3 está incluida la síntesis de 3-fluoro-2-oxindoles combinando las metodologías descritas en los dos anteriores capítulos. Finalmente, en el Capítulo 4, se desarrolla la alquilación fotocatalizada de olefinas electrofílicas a través de sulfinatos de zinc bencílicos y alquílicos.
4

Synthèse et évaluation biologique de nouveaux composés hétérocycliques potentiellement inhibiteurs de protéine-kinases / Synthesis and biological evaluation of new heterocycle compounds potentially inhibitors of protein-kinases

Letribot, Boris 26 January 2015 (has links)
Les protéine-kinases appartiennent à une large famille d’enzymes impliquées dans de multiples processus cellulaires. Habituellement soumises à un fin contrôle, leur dérégulation est à l’origine de nombreuses maladies parmi lesquelles les cancers et les pathologies neurodégénératives. Le développement de puissants inhibiteurs sélectifs des protéine-kinases permettant de réguler leur activité représente une piste prometteuse pour traiter les pathologies associées. Dans le cadre de la recherche de nouveaux inhibiteurs de kinases et la valorisation des produits de la mer en thérapeutique, nous avons envisagé la conception et la synthèse de nouveaux hétérocycles à sous structures 3-alcényl-oxindole, 3-alcényl-azaoxindole et 3-alcényl-diazaoxindole. Bon nombre d’alcaloïdes naturels issus du milieu terrestre ou du milieu marin, ou encore des agents thérapeutiques tel que le Sunitinib présentent une structure de type alcényl-oxindole. Par l’intermédiaire de la chimie du chlorure de 4,5-dichloro-1,2,3-dithiazolium (sel d’Appel), nous avons développé et étudié au départ de divers dérivés azotés à méthylène actif (oxindoles, azaoxindoles et diazaoxindoles) de nouvelles voies d’accès permettant d’obtenir des séries originales de dérivés de 3-alcényl-oxindoles portant au niveau de l’alcène exocyclique des hétérocycles, des amino-nitriles et des thio-nitriles. Impulsé par le fort pouvoir inhibiteur de kinases des bis-oxindoles mimes de l’alcaloïde indirubine, nous avons entrepris la synthèse de nouveaux indirubinoïdes et isoindigoïdes polyazotés. Afin de dégager des relations structure activité, plus de 80 nouveaux dérivés 3-alcényl-oxindoles, azaoxindoles, diazaoxindoles présentant une grande diversité chimique ont été préparés et évalués sur différentes cibles biologiques. Plusieurs de ces dérivés présentent des activités micromolaires sur les kinases DYRK1A, GSK3 et submicromolaire sur CK1. Les évaluations biologiques sur des lignées de cellules cancéreuses ont permis d’identifier plusieurs thio et amino-3-alcényl-oxindoles cytotoxiques avec des activités de l’ordre du micromolaire. / Deregulation of protein kinases leads to numerous pathologies such as cancers and neurodegenerative diseases. In order to identify new scaffolds able to inhibit this proteins we synthesized new 3-alkenyl-oxindoles. By the mean of Appel’s salt chemistry, we develop a new synthetic route to this skeleton. Our approach allows variation of the substituent of the exocyclic akene which can be functionalized by heterocycles, amino-nitriles or thio-nitrile which are obtained after selective ring opening of (1,2,3)-dithiazoles. In another part, given powerful indirubin kinase inhibitory potency, we synthesized new analogs indiribunoids and isoindigoids. In both cases (3-akenyl-oxindoles from Appel’s salt chemistry and indigoids), the aromatic ring were substituted by various electron withdrawing group and nitrogen were incorporated to determinate structure activity relationship. All this 80 original 3-alkenyl-oxindoles were evaluated for their ability to inhibit kinase activity and cell proliferation.
5

Complexos de cobre com análogos de produtos naturais encontrados em organismos marinhos com atividade antitumoral / Copper complexes with analogues of natural products found in marine organisms with antitumor activity

Tofik, Veridiana de Freitas 06 December 2018 (has links)
Neste trabalho foram sintetizados complexos de cobre(II) com derivados imínicos da isatina, incluindo isatinas bromadas semelhantes a compostos encontrados em gastrópodes, a fim de compará-los com o composto já produzido e investigado [Cu(isaepy)], complexo de cobre(II) com base de Schiff feita a partir da isatina e 2-aminoetilpiridina. A isatina é um oxindol produzido em algumas plantas, também encontrado no tecido de mamíferos, com propriedades antitumorais naturais. Isatinas bromadas foram previamente constatadas como mais citotóxicas frente a células tumorais do que a isatina sem substituições. O objetivo principal foi verificar se a presença de bromo nos compostos análogos ao [Cu(isaepy)] levaria a um aumento da atividade antitumoral, assim como maior interação com DNA, alvo usual de metalofármacos. Depois de sintetizados, os compostos foram caracterizados por análise elementar (CHN), espectroscopia no infravermelho, espectroscopia UV/Vis e EPR. Foram feitos testes de citotoxicidade pelo método MTT com células de sarcoma uterino (MES-SA e MES-AS/Dx5, esta última resistente a doxorrubicina), adenocarcinoma cervical (HeLa) e células não cancerosas de fibroblasto humano P4. Adicionalmente, foram feitos testes de interação com DNA por UV/Vis e dicroísmo circular, além de testes de clivagem de DNA plasmidial. De modo geral, foi demonstrado que a simetria tetragonal em torno do cobre, determinada pelo EPR, é importante para a citotoxicidade dos complexos, que dessa forma podem se intercalar ao DNA e impedir sua replicação, por acabar distorcendo a hélice, e pela habilidade de realizarem clivagem oxidativa das fitas. [Cu(isaepy)] e seus análogos bromados demonstraram uma atividade citotóxica muito parecida, assim como grau de interação e clivagem com DNA. Conclui-se que, embora a presença de bromo nos análogos de [Cu(isaepy)] não levem a um aumento de atividade antitumoral, como observado em ligantes correlatos livres, nossos estudos apontam para diferentes fontes naturais (animal ou vegetal) para obtenção de precursores de novos compostos antitumorais. / In the present work, copper(II) complexes were synthesized with isatin derived imine ligands, including brominated oxindoles similar to compounds found in gastropods, in order to compare their reactivity with that of [Cu(isaepy)], a Schiff base-copper(II) complex already investigated, obtained with the precursors isatin and 2-aminoethylpyridine. Isatin is a natural oxindole extracted from plants, and also found in mammal tissue, with antitumor properties. Brominated isatins were previously described as much more cytotoxic, towards tumor cells, than unsubstituted isatin. The aim of this work was to verify if the presence of brome in analogue [Cu(isaepy)] compounds would increase their antitumor activity, along with higher DNA interaction, an usual target for metallodrugs. The copper(II) complexes were synthesized and then characterized through elemental analyses (CHN), infrared, UV/Vis and EPR spectroscopies. Cytotoxicity tests were carried out using MTT assay with cells lines MES-SA e MES-SA/Dx5 (uterine sarcome, sensitive and resistent to doxorubicin), HeLa (cervical adenocarcinoma) and non-tumor cells, human fibroblast P4. Additionally, DNA interaction experiments were carried out through UV/Vis spectroscopy and circular dichroism, and at last, DNA cleavage experiments with the studied complexes. In general, it was shown that a tetragonal symmetry around copper, shown by EPR, is very important to the complexes toxicity, since in that way they are able to intercalate DNA, and prevent its replication, as a consequence of double helix distortion, and eventual oxidative cleavage. [Cu(isaepy)] and its brominated analogues demonstrated a very similar cytotoxicity towards cancer cells, as well as quite same level of DNA interaction and cleavage. Although the presence of brome did not increase significantly their antitumor activity, as verified with the free isatin derivatives, our studies pointed to different natural sources to obtain precursors for such new antitumor compounds.
6

Síntesis de 2-oxindoles 3,3-disustituidos por alquilación desacilativa

Molina, Cynthia 30 July 2020 (has links)
Esta memoria consta de una introducción general y tres capítulos. En la introducción general, se muestra la importancia del anillo de oxindol, describiendo productos naturales o con actividad biológica que lo contienen en su estructura y comentando algunas de sus aplicaciones biológicas más relevantes. Además, se detallan diferentes técnicas para la síntesis de derivados de oxindol, destacando las metodologías que emplean la alquilación desacilativa. En el capítulo I se muestra una alquilación desacetilativa de derivados de 3-acetil-3-alquil-2-oxindoles con alquenos electrofílicos. En el capítulo II se describe la síntesis de derivados de 2-oxindoles 3,3-disustituidos a través de la alquilación desacetilativa usando haluros de alquilo y alquenos electrofílicos y mediante la alilación desacetilativa catalizada por paladio usando alcoholes alílicos. Finalmente, en el capítulo III, se estudia la reacción aldólica desacetilativa entre 3-fluorooxindoles y aldehídos.
7

Useful strategies for the synthesis of 3,3’- disubstituted 2-oxindoles and homoallyl alcohols

Moreno-Cabrerizo, Cristina 18 March 2021 (has links)
La tesis doctoral describe estrategias útiles y sencillas para las síntesis de 2-oxindoles 3,3'-disustituídos y alcoholes homoalílicos. La memoria se divide en dos grandes bloques: el primero referido a la alquilación desacilativa como método para la síntesis de 2-oxindoles 3,3'-disustituídos que engloba la introducción I, el capítulo I titulado alquilación desacilativa para la síntesis de 2-oxindoles 3,3'-disustituídos y capítulo II titulado bromación desacilativa para la síntesis de 3,3'-bioxindoles y aislamiento de 3-bromooxindoles. La segunda parte se refiere a fotocatálisis y metalofotocatálisis como nuevos métodos de síntesis orgánica y engloba la introducción II, capítulo III titulado fotocatálisis para la síntesis de 3,3'-bioxindoles y capítulo IV titulado catálisis dual para la alilación de aldehídos.
8

Synthèse et désymétrisation d'arylcyclohexa-2,5-diènes : application à la synthèse totale de l'épi-Elwesine

Rousseau, Géraldine 13 November 2008 (has links)
La désymétrisation d’arylcyclohexa-2,5-diènes est une méthode très efficace pour obtenir en une seule étape des squelettes complexes à partir de synthons simples. Lors de cette thèse, une nouvelle approche à la synthèse d’arylcyclohexadiènes porteur d’un centre quaternaire a été développée. L’une des structures synthétisées par cette voie a ensuite été désymétrisée par une réaction d’hydroamination diastéréosélective, nous permettant de réaliser la première synthèse énantiosélective de l’épi-Elwesine. Notre démarche s’est ensuite orientée vers la synthèse et la désymétrisation de nouveaux types de diènes spirocycliques de type oxindoles. La présence dans ces diènes de deux faces très différenciées nous a permis de réaliser des processus complètement diastéréosélectifs. De plus une nouvelle séquence réarrangement-alkylation a été mise au point, nous permettant d’accéder efficacement à des squelettes de type phénanthridinones de façon régio- et diastéréosélective. / The desymmetrization of arylcyclohexa-2,5-dienes is a powerful method to synthesize complex structures from simple synthons in a single step. We first developed a new protocol to obtain arylcyclohexa-2,5-dienes bearing a quaternary center. One of these structures was desymmetrized via a diastereoselective hydroamination and further elaborated into epi-Elwesine, an Amaryllidaceae alkaloid. We next turned our attention towards the synthesis and desymmetrization of spirocyclic cyclohexadienes. Diastereoselective processes were carried out due to the presence of two well- differentiated faces. A new rearrangement-alkylation process was developed and provides efficient access to phenanthridinones regio- and diastereoselectively.
9

Development of catalytic enantioselective C-C bond-forming and cascade transformations by merging homogeneous or heterogeneous transition metal catalysis with asymmetric aminocatalysis

Afewerki, Samson January 2014 (has links)
Chiral molecules play a central role in our daily life and in nature, for instance the different enantiomers or diastereomers of a chiral molecule may show completely different biological activity. For this reason, it is a vital goal for synthetic chemists to design selective and efficient methodologies that allow the synthesis of the desired enantiomer. In this context, it is highly important that the concept of green chemistry is considered while designing new approaches that eventually will provide more environmental and sustainable chemical synthesis.The aim of this thesis is to develop the concept of combining transition metal catalysis and aminocatalysis in one process (dual catalysis). This strategy would give access to powerful tools to promote reactions that were not successful with either transition metal catalyst or the organocatalyst alone. The protocols presented in this thesis based on organocatalytic transformations via enamine or iminium intermediates or both, in combination with transition metal catalysis, describes new enantioselective organocatalytic procedures that afford valuable compounds with high chemo- and enantioselectivity from inexpensive commercial available starting materials. In paper I, we present a successful example of dual catalysis: the combination of transition metal activation of an electrophile and aminocatalyst activation of a nucleophile via enamine intermediate. In paper II, the opposite scenario is presented, here the transition metal activates the nucleophile and the aminocatalyst activates the electrophile via an iminium intermediate. In paper III,we present a domino Michael/carbocyclisation reaction that is catalysed by a chiral amine (via iminium/enamine activation) in combination with a transition metal catalysts activation of an electrophile. In paper IV, the concept of dual catalysis was further extended and applied for the highly enantioselective synthesis of valuable structural scaffolds, namely poly-substituted spirocyclic oxindoles. Finally, in paper V the concept of dual catalysis was expanded, by investigating more challenging and environmentally benign processes, such as the successful combination of a heterogeneous palladium and amine catalysts for the highly enantioselective synthesis of functionalised cyclopentenes, containing an all carbonquaternary stereocenter, dihydrofurans and dihydropyrrolidines.
10

Organocatalytic Cascade Cyclizations for the Enantioselective Synthesis of Spirooxindoles

Kayal, Satavisha January 2016 (has links) (PDF)
The thesis entitled “Organocatalytic Cascade Cyclizations for the Enantioselective Synthesis of Spirooxindoles” is divided into three chapters. Chapter 1: Catalytic Enantioselective Michael Addition/Cyclization Cascade of 3-Isothiocyanato Oxindoles with Nitroolefins A myriad of spirocyclic frameworks present in natural product, and pharmaceutically important compounds, has attracted the synthetic organic chemists to explore their preparation in enantioselective manner. Consequently various strategies have been devised for efficiently accessing highly functionalized spirooxindoles. Among these strategies, the use of 3-isothiocyanato oxindoles as the building block appeared as the most popular one. The combination of 3-isothiocyanato oxindoles and a variety of electrophiles have already been reported. However one of the most popular electrophiles, nitroolefins, has never been used in the reaction with 3-isothiocyanato oxindoles. In this chapter, a highly efficient catalytic asymmetric Michael addition/cyclization cascade reaction between 3-isothiocyanato oxindoles and β-substituted nitroolefins with the help of a cinchonidine-derived bifunctional thiourea catalyst has been discussed. Highly functionalized spirooxindoles containing three successive stereocenters were obtained in high yield with moderate to good diastereo- and enantioselectivity. Reference: Kayal, S.; Mukherjee, S. Eur. J. Org. Chem. 2014, 6696-6700. Chapter 2: Catalytic Aldol-Cyclization Cascade of 3-Isothiocyanato Oxindoles with α-Ketophosphonates for the Enantioselective Synthesis of β-Amino-α-Hydroxyphosphonates The oxindole scaffold containing a quaternary stereocenter at the C3 position is a privileged structural motif present in many biologically active molecules and natural products. In this respect, spirooxindoles have received special attention during the past few years. Similarly, β-Amino and/or hydroxy functionalized phosphonic acids and their derivatives are found to display inhibitory activities towards a range of enzymes such as renin, HIV protease, thrombin, and various classes of protein tyrosine kinases and phosphatases. Considering the importance of both oxindole and β-amino-α-hydroxyphosphonic acid, we reasoned that highly functionalized phosphonic acid derivatives based on a spirooxindole framework could be of potential biological significance, if synthesized in enantiopure form This chapter deals with a cascade aldol-cyclization reaction between 3-isothiocyanato oxindoles and α-ketophosphonates for the enantioselective synthesis of spirooxindole-based β-amino-α-hydroxyphosphonate derivatives. Catalyzed by cinchona alkaloid-based bifunctional thiourea derivatives, this protocol delivers 2-thioxooxazolidinyl phosphonates bearing two adjacent quaternary stereogenic centers, generally in high yields with excellent diastereo- and enantioselectivities. Both the product enantiomers are accessible with nearly equally high level of enantioselectivity. Reference: Kayal, S.; Mukherjee, S. Org. Lett. 2015, 17, 5508-5511. Chapter 3: Catalytic Michael Addition/Cyclization Cascade of 3-Isothiocyanato Oxindoles with Cyclic α,β-Unsaturated Ketones: A Concise Enantioselective Synthesis of Bispiro[indoline-3,2'-pyrrolidine] Among different spirocyclic cores, the spirooxindole framework containing pyrrolidinyl ring represents a very important class owing to their biological activities such as antimicrobial, anticancer, antihypertensive, antidiabetic, antimycobacterial and antitubercular properties. Similarly, the bispirooxindole scaffold recently has drawn considerable interests because of its exclusive structural and stereochemical diversity. Only a few examples have been reported till date for enantioselective construction of the pharmaceutically important bispirooxindole architectures. Considering the importance of bispirooxindoles and pyrrolidinyl spirooxindole scaffolds, we were interested in merging them in a single molecular framework. In this chapter, a Michael addition/cyclization cascade reaction between 3-isothiocyanato oxindoles and exocyclic enones for the enantioselective synthesis of 3,2′-pyrrolidinyl bispirooxindole derivatives has been illustrated. With the help of a quinine-derived bifunctional squaramide as the catalyst, this protocol delivers bispirooxindoles bearing three contiguous stereogenic centers, in high yields and generally with outstanding diastereo- and enantioselectivity. Reference: Kayal, S.; Mukherjee, S. manuscript under preparation.

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