Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/1931
Título: | Dialkyl imidazolinones from alpha,alpha-dialkyl glycines |
Autor(es): | Costa, Susana P. G. Maia, Hernâni L. S. Lima, Sílvia M. M. A. Pereira |
Palavras-chave: | Alpha,alpha-dialkyl glycines Dialkyl imidazolinones |
Data: | 2003 |
Editora: | American Peptide Society |
Revista: | Biopolymers |
Resumo(s): | In recent years, our group has been involved in the use of the Ugi-Passerini reaction for the synthesis of several alpha,alpha-dialkylglycines. The C-terminal amide bond of the resulting Ugi adducts 1 proved to be very sensitive to TFA, cleaving readily by a mechanism involving an oxazolinium-type intermediate 2. This intermediate allows in situ functionalization of the C-terminus by reaction with several nucleophiles, affording different derivatives such as free acids, esters and amides. Our previous results suggested that a dipeptide could be obtained if an amino acid ester was used as the nucleophile. The results obtained so far indicate that although a small amount the required dipeptides 3 is formed, 5,5-dialkyl-imidazolin-4-ones 4 are the major products. These may result from competitive attack at the less hindered C-2 of the oxazolinium intermediate, followed by rearrangement. |
Tipo: | Resumo em ata de conferência |
URI: | https://hdl.handle.net/1822/1931 |
ISBN: | 0-9715560-1-6 |
ISSN: | 0006-3525 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CDQuim - Comunicações e Proceedings |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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APS2003.pdf | 57,37 kB | Adobe PDF | Ver/Abrir |