1086602-48-3Relevant academic research and scientific papers
New synthesis of methyl 5-aryl or heteroaryl pyrrole-2-carboxylates by a tandem Sonogashira coupling/5-endo-dig-cyclization from β-iododehydroamino acid methyl esters and terminal alkynes
Queiroz, Maria-Jo?o R.P.,Begouin, Agathe,Pereira, Goreti,Ferreira, Paula M.T.
, p. 10714 - 10720 (2008/12/23)
A new and versatile 'Pd'/CuI catalyzed protocol was developed for the synthesis in good to high yields of substituted pyrroles from N-Boc-β-iododehydroamino acid methyl esters and several terminal alkynes. This one-pot, two-step procedure occurs by a Sonogashira coupling followed by a 5-endo-dig-cyclization, which involves the nitrogen atom of the dehydroamino acid. After several experiments using different Pd(0) and Pd(II) species it was possible to establish the more general reaction conditions, which are: the use of a Pd(II) catalyst, CuI and Cs2CO3 as base in dry DMF at 70 °C. The best yields were obtained with arylacetylenes bearing electron-donating groups and with electron-rich heteroarylacetylenes.
