Please use this identifier to cite or link to this item:

TitleSonogashira cross-couplings of dehydroamino acid derivatives and phenylacetylenes
Author(s)Abreu, Ana S.
Ferreira, Paula M. T.
Queiroz, Maria João R. P.
Gatto, Emanuela
Venanzi, Mariano
KeywordsAmino acids
Sonogashira coupling
Issue date2004
JournalEuropean Journal of Organic Chemistry
Citation"European journal of organic chemistry". (2004) 3985-3991.
Abstract(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.
AccessOpen access
Appears in Collections:CDQuim - Artigos (Papers)

Files in This Item:
File Description SizeFormat 
EUJOC-MJQ.pdf166,19 kBAdobe PDFView/Open

Partilhe no FacebookPartilhe no TwitterPartilhe no DeliciousPartilhe no LinkedInPartilhe no DiggAdicionar ao Google BookmarksPartilhe no MySpacePartilhe no Orkut
Exporte no formato BibTex mendeley Exporte no formato Endnote Adicione ao seu ORCID