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https://hdl.handle.net/1822/72914
Título: | Synthesis of substituted oxazoles from N-acyl-beta-hydroxyamino acid derivatives |
Autor(es): | Ferreira, Paula M. T. Monteiro, Luís S. Pereira, Goreti |
Palavras-chave: | Amino acids Dehydroamino acids Iodine Cyclization Oxygen heterocycles Nitrogen heterocyles |
Data: | Set-2008 |
Editora: | Wiley-VCH Verlag |
Revista: | European Journal of Organic Chemistry |
Resumo(s): | 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). |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/72914 |
DOI: | 10.1002/ejoc.200800602 |
ISSN: | 1434-193X |
Versão da editora: | https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/ejoc.200800602 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CDQuim - Artigos (Papers) |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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2008-Eur. J. Org. Chem. 4676.pdf | 208,17 kB | Adobe PDF | Ver/Abrir |