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https://hdl.handle.net/1822/2016
Título: | Sonogashira cross-couplings of dehydroamino acid derivatives and phenylacetylenes |
Autor(es): | Abreu, Ana S. Ferreira, Paula M. T. Queiroz, Maria João R. P. Gatto, Emanuela Venanzi, Mariano |
Palavras-chave: | Amino acids Phenylacetylenes Sonogashira coupling Palladium Benzo[b]thiophenes Fluorescence |
Data: | 2004 |
Editora: | Wiley |
Revista: | European Journal of Organic Chemistry |
Citação: | "European journal of organic chemistry". (2004) 3985-3991. |
Resumo(s): | Several phenylacetylenes were coupled under Sonogashira cross coupling conditions with the methyl esters of N-(tert-butoxycarbonyl)-(E)-beta-bromo or beta, beta-dibromodehydroalanine to give respectively beta-substituted or beta,beta-bis-substituted dehydroalanines. The beta-substituted dehydroalanines were obtained in good to high yields (60-90%) under the usual Sonogashira conditions (1 equiv. of the phenylacetylene, 1 mol% Pd(PPh3)4, 2 mol% CuI 18 equiv. NEt3 in acetonitrile, 24h at rt) with maintenance of the stereochemistry. The beta,beta-bis-substituted dehydroalanines were in turn obtained in moderate to good yields (44-63%) requiring modified Sonogashira conditions (4 equiv. of the phenylacetylene,10 mol% PdCl2(PPh3)2, 20 mol% CuI, 1.4 equiv. Cs2CO3, 2h at reflux of acetonitrile). In the latter reactions some phenylacetylene dimer and the (E)-isomer of the mono substituted coupled products were also isolated in some extent. The Sonogashira products which were obtained from the 4-bromophenylacetylene were reacted with functionalized benzo[b]thiophenes under C-C or C-N palladium-catalyzed cross-coupling conditions. Preliminary fluorescence studies were performed for mono and disubstituted 4-aminophenylacetylenic dehydroamino acids and for the benzo[b]thiophene derivatives. The results showed that some of the dehydroalanines prepared can be used as fluorescent probes. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/2016 |
DOI: | 10.1002/ejoc.200400145 |
ISSN: | 1434-193X |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CDQuim - Artigos (Papers) |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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EUJOC-MJQ.pdf | 166,19 kB | Adobe PDF | Ver/Abrir |