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https://hdl.handle.net/1822/2072
Título: | 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(es): | Lima, Sílvia M. M. A. Pereira Costa, Susana P. G. Maia, Hernâni L. S. |
Palavras-chave: | Aminoácidos alfa,alfa-dissubstituidos Reacção de Ugi |
Data: | 2002 |
Citação: | BENEDETTI, E.; PEDONE, C., ed lit. – “European peptide symposium, 27, Napoli, 2002 : proceedings”. [S.l.] : Ed. Ziino, [2002?]. p. 250-251. |
Resumo(s): | 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. |
Tipo: | Resumo em ata de conferência |
URI: | https://hdl.handle.net/1822/2072 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CDQuim - Comunicações e Proceedings |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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Manuscript.doc.pdf | 35,26 kB | Adobe PDF | Ver/Abrir |