An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction
Autor(a) principal: | |
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Data de Publicação: | 2002 |
Outros Autores: | , |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/1822/2072 |
Resumo: | Owing to steric hindrance, syntheses of and reactions with alfa,alfa-dialkylglycines are very slow; thus, most methods of peptide synthesis are of little use to handle these compounds when the alfa-alkyl groups are larger than methyl. Ugi’s four-component reaction is appropriate to synthesise these amino acids [1], but for peptide synthesis it presents two drawbacks, i.e. (i) peptide isonitriles racemise above –20 ºC and (ii) an unavoidable alkyl group in the reaction product needs to be cleaved [2]. Reactions with alfa,alfa-dialkylglycines are too slow to allow performing them at –20 ºC. Isonitriles have been devised to allow mild cleavage of the amide bond at the C-terminus of the Ugi adduct, but in alfa,alfa-dialkylglycine derivatives the amide bond generated by the isonitrile is sufficiently labile [3] to allow mild cleavage. Thus, as shown in the scheme below, we devised a simple and fairly efficient approach to routine synthesis of peptides containing alfa,alfa-dialkylglycine residues, using commercially available reagents. |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reactionAminoácidos alfa,alfa-dissubstituidosReacção de UgiOwing to steric hindrance, syntheses of and reactions with alfa,alfa-dialkylglycines are very slow; thus, most methods of peptide synthesis are of little use to handle these compounds when the alfa-alkyl groups are larger than methyl. Ugi’s four-component reaction is appropriate to synthesise these amino acids [1], but for peptide synthesis it presents two drawbacks, i.e. (i) peptide isonitriles racemise above –20 ºC and (ii) an unavoidable alkyl group in the reaction product needs to be cleaved [2]. Reactions with alfa,alfa-dialkylglycines are too slow to allow performing them at –20 ºC. Isonitriles have been devised to allow mild cleavage of the amide bond at the C-terminus of the Ugi adduct, but in alfa,alfa-dialkylglycine derivatives the amide bond generated by the isonitrile is sufficiently labile [3] to allow mild cleavage. Thus, as shown in the scheme below, we devised a simple and fairly efficient approach to routine synthesis of peptides containing alfa,alfa-dialkylglycine residues, using commercially available reagents.Universidade do MinhoLima, Sílvia M. M. A. PereiraCosta, Susana P. G.Maia, Hernâni L. S.20022002-01-01T00:00:00Zconference objectinfo:eu-repo/semantics/publishedVersionapplication/pdfhttp://hdl.handle.net/1822/2072engBENEDETTI, E.; PEDONE, C., ed lit. – “European peptide symposium, 27, Napoli, 2002 : proceedings”. [S.l.] : Ed. Ziino, [2002?]. p. 250-251.info: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:RCAAP2024-05-11T05:44:34Zoai:repositorium.sdum.uminho.pt:1822/2072Portal AgregadorONGhttps://www.rcaap.pt/oai/openairemluisa.alvim@gmail.comopendoar:71602024-05-11T05:44:34Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction |
title |
An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction |
spellingShingle |
An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction Lima, Sílvia M. M. A. Pereira Aminoácidos alfa,alfa-dissubstituidos Reacção de Ugi |
title_short |
An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction |
title_full |
An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction |
title_fullStr |
An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction |
title_full_unstemmed |
An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction |
title_sort |
An improved approach to the synthesis of N-acyl-alpha,alpha-dialkyl glycines and their esters and amides using Ugi’s four-component reaction |
author |
Lima, Sílvia M. M. A. Pereira |
author_facet |
Lima, Sílvia M. M. A. Pereira Costa, Susana P. G. Maia, Hernâni L. S. |
author_role |
author |
author2 |
Costa, Susana P. G. Maia, Hernâni L. S. |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Lima, Sílvia M. M. A. Pereira Costa, Susana P. G. Maia, Hernâni L. S. |
dc.subject.por.fl_str_mv |
Aminoácidos alfa,alfa-dissubstituidos Reacção de Ugi |
topic |
Aminoácidos alfa,alfa-dissubstituidos Reacção de Ugi |
description |
Owing to steric hindrance, syntheses of and reactions with alfa,alfa-dialkylglycines are very slow; thus, most methods of peptide synthesis are of little use to handle these compounds when the alfa-alkyl groups are larger than methyl. Ugi’s four-component reaction is appropriate to synthesise these amino acids [1], but for peptide synthesis it presents two drawbacks, i.e. (i) peptide isonitriles racemise above –20 ºC and (ii) an unavoidable alkyl group in the reaction product needs to be cleaved [2]. Reactions with alfa,alfa-dialkylglycines are too slow to allow performing them at –20 ºC. Isonitriles have been devised to allow mild cleavage of the amide bond at the C-terminus of the Ugi adduct, but in alfa,alfa-dialkylglycine derivatives the amide bond generated by the isonitrile is sufficiently labile [3] to allow mild cleavage. Thus, as shown in the scheme below, we devised a simple and fairly efficient approach to routine synthesis of peptides containing alfa,alfa-dialkylglycine residues, using commercially available reagents. |
publishDate |
2002 |
dc.date.none.fl_str_mv |
2002 2002-01-01T00:00:00Z |
dc.type.driver.fl_str_mv |
conference object |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/1822/2072 |
url |
http://hdl.handle.net/1822/2072 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
BENEDETTI, E.; PEDONE, C., ed lit. – “European peptide symposium, 27, Napoli, 2002 : proceedings”. [S.l.] : Ed. Ziino, [2002?]. p. 250-251. |
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.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 |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
mluisa.alvim@gmail.com |
_version_ |
1817544724495466496 |