Synthesis 2004(15): 2574-2578  
DOI: 10.1055/s-2004-831195
PAPER
© Georg Thieme Verlag Stuttgart · New York

Metal Triflates-Catalyzed Conjugate Addition of Homochiral Pyrroles to α,β-Unsaturated Esters

Canan Ünaleroglu*a, Baris Temellia, Ayhan S. Demirb
a Hacettepe University, Department of Chemistry, 06532 Ankara, Turkey
b Middle East Technical University, Department of Chemistry, 06531 Ankara, Turkey
Fax: +90(312)2992163; e-Mail: canan@hacettepe.edu.tr;
Further Information

Publication History

Received 24 May 2004
Publication Date:
26 August 2004 (online)

Abstract

The Friedel-Crafts reaction of homochiral pyrrole derivatives with α,β-unsaturated esters catalyzed by metal triflates furnished conjugate addition products. The best yields were obtained by using yttrium triflate and methyl 4-phenyl-2-oxobut-3-enoate (2a). The addition worked regioselectively at C-5 of pyrrole. The diastereoisomers were separated by column chromatography.