Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST
Autor(a) principal: | |
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Data de Publicação: | 2011 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/4197 |
Resumo: | This work describes the study of the chemical behavior of trifluoromethyl substituted heterocycles as 1H-pyrazoles, 2-pyrazolines, 2H-cromenones and isoxazolines in reactions with DAST, with the aim of evaluating possible reactions in the oxygenated sites, aiming mainly the insertion of fluorine atoms in these molecules. Trifluoromethylated heterocycle precursors such as 1H-pyrazoles (2), 2-pyrazolines (6, 8), 2H-cromenones (10-14), isoxazolines (20) were obtained from cyclic and acyclic trifluoroacetylated vinyl ethers (1) and hydrazines, hydrazides, diketones, aldehydes and hydroxylamine employing conventional or multi-component cyclocondensation reaction procedures. When the reactions were carried out in dichloromethane as solvent and DAST in slight excess (1:2), at room temperature for a reaction time of 24 hours, it was observed monofluorination reactions on 4-hydroxyalkyl-1H-pyrazoles (2) (70-75%), difluorination reactions in 4-formylethyl-1H-pyrazoles (4e) (71%), intramolecular cyclization on 4-hydroxyalkyl-4,5-dihydro-1H-pyrazoles (6) (74-80%) and dehydration reactions in 3-(alkyl/aryl)-4,5-dihydropyrazoles (8) (65-75%). Reactions of 2-hydroxy-2H-chromenones (10-14) with DAST by similar reactions conditions, were chemoselective, despite the various reactive sites present in these compounds, and exclusively by the SN2 nucleophilic substitution at the C-2-, conduted to the monofluorinated tetrahydro-2H-chromenones (15-19) (63-81 %). Finally, despite the partial structural similarity with 2-hydroxy-2H-cromenones (10-14), were performed reactions of 4,5-dihydroisoxazoles (20) in the presence of DAST, which resulted only in dehydration products (21) (73-85%) similarly to the results for 3-(alkyl/aryl)-4,5- dihydropyrazoles (8). |
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Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DASTStudy of the chemical behavior of trifluoromethyl substituted heterocycles in reactions with DASTQuímicaQuímica orgânicaCompostos heterocíclosSíntese químicaCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICAThis work describes the study of the chemical behavior of trifluoromethyl substituted heterocycles as 1H-pyrazoles, 2-pyrazolines, 2H-cromenones and isoxazolines in reactions with DAST, with the aim of evaluating possible reactions in the oxygenated sites, aiming mainly the insertion of fluorine atoms in these molecules. Trifluoromethylated heterocycle precursors such as 1H-pyrazoles (2), 2-pyrazolines (6, 8), 2H-cromenones (10-14), isoxazolines (20) were obtained from cyclic and acyclic trifluoroacetylated vinyl ethers (1) and hydrazines, hydrazides, diketones, aldehydes and hydroxylamine employing conventional or multi-component cyclocondensation reaction procedures. When the reactions were carried out in dichloromethane as solvent and DAST in slight excess (1:2), at room temperature for a reaction time of 24 hours, it was observed monofluorination reactions on 4-hydroxyalkyl-1H-pyrazoles (2) (70-75%), difluorination reactions in 4-formylethyl-1H-pyrazoles (4e) (71%), intramolecular cyclization on 4-hydroxyalkyl-4,5-dihydro-1H-pyrazoles (6) (74-80%) and dehydration reactions in 3-(alkyl/aryl)-4,5-dihydropyrazoles (8) (65-75%). Reactions of 2-hydroxy-2H-chromenones (10-14) with DAST by similar reactions conditions, were chemoselective, despite the various reactive sites present in these compounds, and exclusively by the SN2 nucleophilic substitution at the C-2-, conduted to the monofluorinated tetrahydro-2H-chromenones (15-19) (63-81 %). Finally, despite the partial structural similarity with 2-hydroxy-2H-cromenones (10-14), were performed reactions of 4,5-dihydroisoxazoles (20) in the presence of DAST, which resulted only in dehydration products (21) (73-85%) similarly to the results for 3-(alkyl/aryl)-4,5- dihydropyrazoles (8).Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorEste trabalho descreve o estudo do comportamento químico de heterociclos trifluormetil substituídos como 1H-pirazóis, 2-pirazolinas, 2H-cromenonas e isoxazolinas na presença de DAST (Dietilamino trifluoreto de enxofre), tendo por objetivo avaliar possíveis reações em sítios oxigenados, e visando, principalmente, a inserção de átomos de flúor nestas moléculas. Os heterociclos trifluormetil substituídos precursores 1H-pirazóis (2), 2-pirazolinas (6, 8), 2H-cromenonas (10-14), isoxazolinas (20) foram obtidos empregando vinil cetonas acíclicas e cíclicas (1) e hidrazinas, hidrazidas, dicetonas, aldeídos ou hidroxilamina via reações de ciclocondensação convencionais ou reações multi-componentes. A partir de reações que foram procedidas em diclorometano como solvente e DAST em pequeno excesso (1:2) à temperatura ambiente, por um tempo reacional de 24 horas, foi possível observar reações de fluoração em 4-hidroxialquil pirazóis (2) (70-75%), reações de difluoração em 4-formiletil pirazóis (4e) (71%), ciclização intramolecular em 4-hidroxialquil-4,5- diidropirazóis (6) (74-80%) e reações de desidratação em 3-(alquil/aril)-4,5-diidropirazóis (8) (65-75%). As reações de 2-hidróxi-2H-cromenonas (10-14) com DAST foram quimioseletivas, considerando os diversos sítios reativos presentes nestes compostos, e conduziram exclusivamente, via substituição nucleofílica, a reações de monofluoração no C-2 (15-19) (63-81%). Finalmente, apesar da semelhança estrutural parcial com 2-hidróxi-2H-cromenonas (10-14), as reações de 4,5-diidroisoxazóis (20) na presença de DAST conduziram somente a produtos de desidratação (21) (73-85%) de maneira similar aos resultados obtidos para 3-(alquil/aril)-4,5- diidropirazóis (8).Universidade Federal de Santa MariaBRQuímicaUFSMPrograma de Pós-Graduação em QuímicaBonacorso, Helio Gauzehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788537E0Zanatta, Nilohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783100P9Siqueira, Geonir Machadohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4782774H9Appelt, Helmoz Roseniaimhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4723562D2Martins, Marcos Antonio Pintohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783192P3Porte, Liliane Medianeira Favero2017-05-182017-05-182011-03-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfapplication/pdfPORTE, Liliane Medianeira Favero. Study of the chemical behavior of trifluoromethyl substituted heterocycles in reactions with DAST. 2011. 168 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2011.http://repositorio.ufsm.br/handle/1/4197porinfo:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2017-07-25T14:05:09Zoai:repositorio.ufsm.br:1/4197Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2017-07-25T14:05:09Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST Study of the chemical behavior of trifluoromethyl substituted heterocycles in reactions with DAST |
title |
Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST |
spellingShingle |
Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST Porte, Liliane Medianeira Favero Química Química orgânica Compostos heterocíclos Síntese química CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST |
title_full |
Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST |
title_fullStr |
Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST |
title_full_unstemmed |
Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST |
title_sort |
Estudo do comportamento químico de heterociclos trifluormetil substituídos em reações com DAST |
author |
Porte, Liliane Medianeira Favero |
author_facet |
Porte, Liliane Medianeira Favero |
author_role |
author |
dc.contributor.none.fl_str_mv |
Bonacorso, Helio Gauze http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788537E0 Zanatta, Nilo http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783100P9 Siqueira, Geonir Machado http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4782774H9 Appelt, Helmoz Roseniaim http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4723562D2 Martins, Marcos Antonio Pinto http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783192P3 |
dc.contributor.author.fl_str_mv |
Porte, Liliane Medianeira Favero |
dc.subject.por.fl_str_mv |
Química Química orgânica Compostos heterocíclos Síntese química CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
topic |
Química Química orgânica Compostos heterocíclos Síntese química CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
This work describes the study of the chemical behavior of trifluoromethyl substituted heterocycles as 1H-pyrazoles, 2-pyrazolines, 2H-cromenones and isoxazolines in reactions with DAST, with the aim of evaluating possible reactions in the oxygenated sites, aiming mainly the insertion of fluorine atoms in these molecules. Trifluoromethylated heterocycle precursors such as 1H-pyrazoles (2), 2-pyrazolines (6, 8), 2H-cromenones (10-14), isoxazolines (20) were obtained from cyclic and acyclic trifluoroacetylated vinyl ethers (1) and hydrazines, hydrazides, diketones, aldehydes and hydroxylamine employing conventional or multi-component cyclocondensation reaction procedures. When the reactions were carried out in dichloromethane as solvent and DAST in slight excess (1:2), at room temperature for a reaction time of 24 hours, it was observed monofluorination reactions on 4-hydroxyalkyl-1H-pyrazoles (2) (70-75%), difluorination reactions in 4-formylethyl-1H-pyrazoles (4e) (71%), intramolecular cyclization on 4-hydroxyalkyl-4,5-dihydro-1H-pyrazoles (6) (74-80%) and dehydration reactions in 3-(alkyl/aryl)-4,5-dihydropyrazoles (8) (65-75%). Reactions of 2-hydroxy-2H-chromenones (10-14) with DAST by similar reactions conditions, were chemoselective, despite the various reactive sites present in these compounds, and exclusively by the SN2 nucleophilic substitution at the C-2-, conduted to the monofluorinated tetrahydro-2H-chromenones (15-19) (63-81 %). Finally, despite the partial structural similarity with 2-hydroxy-2H-cromenones (10-14), were performed reactions of 4,5-dihydroisoxazoles (20) in the presence of DAST, which resulted only in dehydration products (21) (73-85%) similarly to the results for 3-(alkyl/aryl)-4,5- dihydropyrazoles (8). |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011-03-01 2017-05-18 2017-05-18 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
PORTE, Liliane Medianeira Favero. Study of the chemical behavior of trifluoromethyl substituted heterocycles in reactions with DAST. 2011. 168 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/4197 |
identifier_str_mv |
PORTE, Liliane Medianeira Favero. Study of the chemical behavior of trifluoromethyl substituted heterocycles in reactions with DAST. 2011. 168 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2011. |
url |
http://repositorio.ufsm.br/handle/1/4197 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Química UFSM Programa de Pós-Graduação em Química |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Química UFSM Programa de Pós-Graduação em Química |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
instacron_str |
UFSM |
institution |
UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
_version_ |
1805922138000982016 |