Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives
Autor(a) principal: | |
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Data de Publicação: | 2008 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/1822/72914 |
Resumo: | Several N-acyl-beta-hydroxyamino acids were prepared and treated with di-tert-butyl dicarbonate in the presence of 4-(dimethylamino)pyridine, followed by treatment with N,N,N',N'-tetramethylguanidine to give the corresponding N-acyldehydroamino acids in good to high yields. These were then treated with I-2/K2CO3 followed by 1,8-diazabicyclo[5.4.0]undec-7-ene. The methyl esters of N-acyldehydroaminobutyric acid gave the corresponding substituted oxazoles in good to high yields. The N-acyldehydrophenylalanines gave 5-phenyloxazole derivatives in low to moderate yields together with beta-iododehydrophenylalanines. Under the same conditions, N-acyldehydroalanines failed to give the corresponding oxazoles. However, when the reaction was carried out in the absence of DBU, it was possible to isolate the beta,beta-diiododehydroalanine derivatives. Although the reason for the different reactivities of the N-acyldehydroamino acids is not completely clear to us, cyclic voltammetry studies showed that the less-reactive derivatives have higher reduction potentials. This suggests that the double bonds in dehydroaminobutyric acid derivatives are more susceptible to electrophilic attack by iodine. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008). |
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Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivativesAmino acidsDehydroamino acidsIodineCyclizationOxygen heterocyclesNitrogen heterocylesScience & TechnologySeveral N-acyl-beta-hydroxyamino acids were prepared and treated with di-tert-butyl dicarbonate in the presence of 4-(dimethylamino)pyridine, followed by treatment with N,N,N',N'-tetramethylguanidine to give the corresponding N-acyldehydroamino acids in good to high yields. These were then treated with I-2/K2CO3 followed by 1,8-diazabicyclo[5.4.0]undec-7-ene. The methyl esters of N-acyldehydroaminobutyric acid gave the corresponding substituted oxazoles in good to high yields. The N-acyldehydrophenylalanines gave 5-phenyloxazole derivatives in low to moderate yields together with beta-iododehydrophenylalanines. Under the same conditions, N-acyldehydroalanines failed to give the corresponding oxazoles. However, when the reaction was carried out in the absence of DBU, it was possible to isolate the beta,beta-diiododehydroalanine derivatives. Although the reason for the different reactivities of the N-acyldehydroamino acids is not completely clear to us, cyclic voltammetry studies showed that the less-reactive derivatives have higher reduction potentials. This suggests that the double bonds in dehydroaminobutyric acid derivatives are more susceptible to electrophilic attack by iodine. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).- The Foundation for Science and Technology (FCT) - Portugal and FEDER for financial support through the Centro de Quimica of the Univ. of Minho and through project POCI/QUI/59407/2004.Wiley-VCH VerlagUniversidade do MinhoFerreira, Paula M. T.Monteiro, Luís S.Pereira, Goreti2008-092008-09-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/72914eng1434-193X10.1002/ejoc.200800602https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/ejoc.200800602info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-21T12:32:55ZPortal AgregadorONG |
dc.title.none.fl_str_mv |
Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives |
title |
Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives |
spellingShingle |
Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives Ferreira, Paula M. T. Amino acids Dehydroamino acids Iodine Cyclization Oxygen heterocycles Nitrogen heterocyles Science & Technology |
title_short |
Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives |
title_full |
Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives |
title_fullStr |
Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives |
title_full_unstemmed |
Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives |
title_sort |
Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives |
author |
Ferreira, Paula M. T. |
author_facet |
Ferreira, Paula M. T. Monteiro, Luís S. Pereira, Goreti |
author_role |
author |
author2 |
Monteiro, Luís S. Pereira, Goreti |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Ferreira, Paula M. T. Monteiro, Luís S. Pereira, Goreti |
dc.subject.por.fl_str_mv |
Amino acids Dehydroamino acids Iodine Cyclization Oxygen heterocycles Nitrogen heterocyles Science & Technology |
topic |
Amino acids Dehydroamino acids Iodine Cyclization Oxygen heterocycles Nitrogen heterocyles Science & Technology |
description |
Several N-acyl-beta-hydroxyamino acids were prepared and treated with di-tert-butyl dicarbonate in the presence of 4-(dimethylamino)pyridine, followed by treatment with N,N,N',N'-tetramethylguanidine to give the corresponding N-acyldehydroamino acids in good to high yields. These were then treated with I-2/K2CO3 followed by 1,8-diazabicyclo[5.4.0]undec-7-ene. The methyl esters of N-acyldehydroaminobutyric acid gave the corresponding substituted oxazoles in good to high yields. The N-acyldehydrophenylalanines gave 5-phenyloxazole derivatives in low to moderate yields together with beta-iododehydrophenylalanines. Under the same conditions, N-acyldehydroalanines failed to give the corresponding oxazoles. However, when the reaction was carried out in the absence of DBU, it was possible to isolate the beta,beta-diiododehydroalanine derivatives. Although the reason for the different reactivities of the N-acyldehydroamino acids is not completely clear to us, cyclic voltammetry studies showed that the less-reactive derivatives have higher reduction potentials. This suggests that the double bonds in dehydroaminobutyric acid derivatives are more susceptible to electrophilic attack by iodine. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008). |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008-09 2008-09-01T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/1822/72914 |
url |
http://hdl.handle.net/1822/72914 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
1434-193X 10.1002/ejoc.200800602 https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/ejoc.200800602 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Wiley-VCH Verlag |
publisher.none.fl_str_mv |
Wiley-VCH Verlag |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
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repository.mail.fl_str_mv |
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1777303783672381440 |