Lewis Acid-Catalyzed Synthesis of Functionalized Pyrroles
作者:Orazio A. Attanasi、Stefano Berretta、Lucia De Crescentini、Gianfranco Favi、Gianluca Giorgi、Fabio Mantellini
DOI:10.1002/adsc.200800807
日期:2009.3
Abstractmagnified imageThe synthesis of highly functionalized pyrroles is described. The sequence involves the preliminary preparation of α‐aminohydrazones by Michael addition of primary amines to 1,2‐diaza‐1,3‐butadienes. The treatment of these compounds with dialkyl acetylenedicarboxylates produces α‐(N‐enamino)‐hydrazones that were converted into the corresponding pyrroles by Lewis acid‐catalyzed ring closure. A screening of several Lewis/Brønsted acid catalysts was also performed.