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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

Arilação de Heck da N-Metoxicarbonil-2-Carboximetil-1,2,5,6-Tetraidropiridina com sais de Arildiazonio. Aplicação na sintese da (+ -)-Paroxetina / Heck arylation of the N-Methoxycarbonyl-3-Carboxymethyl-1,2,5,6-Tetrahydropyridine with aryldiazonium salts. Application to the synthesis of (+ -)-Paroxetine

Pastre, Júlio Cezar, 1979- 06 August 2018 (has links)
Orientador: Carlos Roque Duarte Correia / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-06T00:38:56Z (GMT). No. of bitstreams: 1 Pastre_JulioCezar_M.pdf: 2844371 bytes, checksum: 6abfb0e87d60113816e3b01d9a02d6b9 (MD5) Previous issue date: 2005 / Mestrado / Quimica Organica / Mestre em Química
2

Arilações de Heck com sais de diazônio = estudos metodológicos e aplicações nas sínteses de ligantes quirais, produtos naturais e análogos / Heck arylations with diazonium salts : methodology and applications in the synthesis of chiral ligands, natural products and analogues

Moro, Angélica Venturini 16 August 2018 (has links)
Orientador: Carlos Roque Duarte Correia / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-16T12:54:31Z (GMT). No. of bitstreams: 1 Moro_AngelicaVenturini_D.pdf: 11686142 bytes, checksum: b58d89c20ca896f67ba31310774b3fb0 (MD5) Previous issue date: 2010 / Resumo: O presente trabalho foi centrado na arilação de Heck de diferentes olefinas com sais de diazônio e a aplicação dos produtos arilados na síntese de ligantes quirais, produtos naturais e análogos. Nos estudos envolvendo arilação de Heck de estirenos com sais de diazônio foi desenvolvida uma metodologia eficiente, curta, régio- e estereosseletiva para a síntese do resveratrol, do DMU-212 e de análogos. Na reação de Heck de ésteres alílicos com sais de diazônio uma alta quimio-, regio- e estereosseletividade foi obtida. Os ésteres alílicos arilados foram sintetizados em altos rendimentos e com retenção do tradicional grupo de saída. Também foi possível a arilação de ésteres alílicos cíclicos, que foram utilizados na síntese total de kavalactonas naturais. A síntese total da (-)-isoaltolactona foi realizada com sucesso em 12 etapas com 13 % de rendimento global. A etapa-chave envolveu uma reação de Heck altamente estereosseletiva entre o sal de fenildiazônio e diidrofurano quiral. O grupo fenila introduzido diastereosseletivamente teve papel crucial no direcionamento dos demais centros estereogênicos da molécula. Nos estudos visando a síntese da aza-altolactona, dificuldades inesperadas foram encontrados em algumas etapas, em especial na oxidação de álcoois a aldeídos pelo uso de protocolos tradicionais. Esses problemas foram contornados pela alteração da rota sintética, entretanto novos problemas na etapa de lactonização impediram a obtenção da aza-altolactona, até o momento. Novos aminoálcoois quirais foram sintetizados pela arilação de enecarbamatos com sais de diazônio. Esses compostos foram empregados como ligantes quirais na arilação catalítica assimétrica de aldeídos e levaram aos diarilmetanóis em altos rendimentos e excessos enantioméricos. / Abstract: The present work was centered in the Heck arylation of several olefins with diazonium salts and application of the arylated products in the syntheses of chiral ligands, natural products and analogues. In studies involving the Heck arylation of styrenes with diazonium salts an efficient, short, regio- and stereoselective synthesis of resveratrol, DMU-212 and analogues was developed. In the Heck reaction of allylic esters with diazonium salts high chemo-, regio- and stereoselectivity was obtained. The arylated allylic esters were synthesized in high yields and with retention of the traditional leaving group. Moreover, the arylation of cyclic allylic esters was developed, and the products were used in the total synthesis of natural kavalactones. The total synthesis of (-)-isoaltholactone was successfully accomplished in 12 steps in 13 % overall yield. The key-step involved highly stereoselective Heck arylation between the phenyldiazonium salt and chiral dihydrofuran. The phenyl group was introduced with high diastereoselectivity and had a crucial role in directing the formation of the remaining stereocenters of the molecule. In the studies towards the synthesis of aza-altholactone, unexpected difficulties were found in some steps, particularly in the oxidation of alcohols to aldehydes by traditional protocols. These problems were circumvented by changing the synthetic route, but additional problems were found in the lactonization and hampered the obtention of the aza-altholactone, until the present moment. New chiral amino alcohols were synthesized by arylation of enecarbamates with diazonium salts. These compounds were used as chiral ligands in the catalytic asymmetric arylation of aldehydes and the diarylmethanols were prepared in high yields and enantiomeric excesses. / Doutorado / Quimica Organica / Doutor em Ciências
3

Estudo e aplicação sintetica da arilação de Heck-Matsuda de desidrohidroxi esteres e desidroamino esteres / Study and synthetic application of the Heck-Matsuda arylation of dehydrohydroxy esters and dehydroamino esters

Azambuja, Francisco de, 1986- 15 August 2018 (has links)
Orientador: Carlos Roque Duarte Correia / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-15T20:34:49Z (GMT). No. of bitstreams: 1 Azambuja_Franciscode_M.pdf: 6423668 bytes, checksum: 29069e3111714888aee628002e55cf0c (MD5) Previous issue date: 2010 / Resumo: A arilação de acrilatos 2-acetóxi ou acetamido substituídos foi estudada utilizando a reação de Heck com sais de arenodiazônio. Após avaliação do catalisador, solvente, temperatura e acidez do meio reacional na arilação do 2-acetoxiacrilato de metila com o sal tetrafluoroborato de p-metoxifenildiazônio, a melhor condição encontrada emprega Pd2dba3 e 2,6-di-terc-butil-4-metilpiridina em benzonitrila a 110 °C por 3 horas, fornecendo o produto em 59 % de rendimento. A utilização de outros sais de diazônio não foi eficiente e os produtos não foram obtidos. A arilação do 2-acetamidoacrilato de metila ocorreu em metanol a 65 °C, utilizando acetato de paladio (II) e 2,6-di-terc-butil-4-metilpiridina. Os rendimentos ficaram entre 24-73 % utilizando sais de arenodiazônio substituídos com iodo, fluor, metoxi ou nitro, além do 2-naftildiazônio e do benzenodiazônio. Os rendimentos insatisfatórios foram contornados com variando-se o grupo protetor da função amina de acetoxi para trifluoracetoxi. A arilação da olefina 2-trifluoroacetamido acrilato de metila, feita nas mesmas condições, ocorreu em rendimentos de 65-86 % para os mesmos sais. Os adutos nitrogenados 2-metoxilados obtidos foram submetidos a um protocolo eliminação/redução ou alquilação com o uso de BF3.OEt2 e nucleófilos de silano. Os derivados de fenilalanina protegidos foram obtidos em rendimentos variados e constituem uma alternativa para a obtenção de aminoácidos arilados não-naturais, a-substituídos ou não. Uma versão one-pot desta redução foi brevemente estudada mediante adição de hidreto de trietilsilano à reação de Heck. A eficiência desta reação em uma etapa foi comparável ao protocolo em duas etapas / Abstract: The arylation of 2-acetoxy or acetamido substituted acrylates was studied through the Heck reaction with arenediazonium salts. After evaluation of the catalyst, solvent, temperature and acidity of the reaction medium, methyl 2-acetoxyacrylate was arylated with p-methoxyphenyldiazonium tetrafluoroborate under Pd2dba3 catalysis, with 2,6-di-terc-butyl-4-methylpyridine as base in benzonitrile at 110 °C for 3 hours. The Heck adduct was obtained in 59 % of yield. Other diazonium salts did not furnished the expected adducts in good yields. Methyl 2-acetamidoacrylate arylation occurred in methanol at 65 °C, using Pd(OAc)2 as catalyst and 2,6-di-terc-butyl-4-methylpyridine as base. Yields between 24-73 % were observed using diazonium salts substituted with iodine, fluoro, methoxy or nitro groups, besides 2-naphthyl or benzenediazonium tetrafluoroborate. The lower yields were by-passed through methyl 2-trifluoroacetamidoacrylate arylation, under the same conditions, resulting in yields between 65-86 % for the same electrophiles. The aza-2-methoxylated adducts obtained were submitted to an elimination/reduction or alkylation protocol using BF3.OEt2 and silane nucleophiles. The protected phenylalanine derivatives were obtained in low to good yields and represent an alternative to prepare unnatural amino acids, a-substituted or not. A one-pot version of this reduction was briefly studied through triethylsilane hydride addition in the Heck reaction. The efficiency of this reaction was comparable with the two-step protocol / Mestrado / Quimica Organica / Mestre em Química
4

Palladium-Catalysed Couplings in Organic Synthesis : Exploring Catalyst-Presenting Strategies and Medicinal Chemistry Applications

Trejos, Alejandro January 2012 (has links)
Palladium-catalysed coupling reactions have been embraced by synthetic chemists as one of the preferred means for smooth formation of new carbon-carbon bonds: a truly ubiquitous methodology of synthesizing complex molecules. This thesis describes the study of a series of palladium(0)-catalysed C2-arylations of a 1-cyclopentenyl ether, equipped with a chiral (S)-N-methyl-pyrrolidine auxiliary. The investigated olefin was demonstrated to undergo Si-face insertion, providing (R)-configuration of the arylated C2-carbon. In addition, the mild and novel palladium(II)-catalysed dominoHeck/Suzuki β,α-diarylation-reduction of a dimethylaminoethyl-substituted chelating vinyl ether was developed using arylboronic acids as arylating agents in combination with 1,4-benzoquinone (BQ). Further, highly regioselective palladium(II)-catalysed α-and β-monoarylation of the chelating vinyl ether was achieved using either a bidentate ligand or by employing ligand-less conditions. These studies demonstrate that the choice of ligands has a profound effect on the reaction outcome, as productive β,α-diarylation could only be obtained by suppressing the competing β-hydride elimination using BQ as the stabilising ligand and terminal reoxidant. The pivotal role of BQ in the reaction was studied using computer-aided density functional theory calculations. The calculations highlight the crucial role of BQ as a Pd(II)-ligand. In addition of serving as an oxidant of palladium, the calculations support the view that the coordination of BQ to the Pd(II)-centre in the key σ-alkyl complex leads to a low-energy pathway, aided by a strong η2 Pd-BQ donation-back-donation interaction. Furthermore, an investigation of the scope and limitations of novel stereoselective and BQ-mediated palladium(II)-catalysed domino Heck/Suzuki β,α-diarylation reactions, involving metal coordinating cyclic methylamino vinyl ethers and a number of electronically diverse arylboronic acids, conducted. In addition, a set of 4-quinolone-3-carboxylic acids, structurally related to elvitegravir and bearing different substituents on the condensed benzene ring, was designed and synthesized as potential HIV-1 integrase inhibitors. Finally, in an effort to identify a new class of HIV-1 protease inhibitors, four different stereopure β-hydroxy γ-lactam-containing inhibitors were synthesized, biologically evaluated, and co-crystallized with the enzyme. / The time 12:05 for the public defense mentioned in the thesis is incorrect. It will take place at 09:15, 2012-06-08.

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