Synthesis 2009(2): 325-331  
DOI: 10.1055/s-0028-1083263
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Design and Efficient Synthesis of Amino Acid Derived 2-Substituted Imidazoles by Palladium-Catalyzed Cross-Coupling Reactions

Aleš Marek, Jiří Kulhánek, Filip Bureš*
Institute of Organic Chemistry and Technology, Faculty of Chemical Technology, University of Pardubice, nám. Čs. legií 565, Pardubice 532 10, Czech Republic
Fax: +420(46)6037068; e-Mail: filip.bures@upce.cz;
Further Information

Publication History

Received 18 September 2008
Publication Date:
12 December 2008 (online)

Abstract

Optically active imidazole derivatives featuring an α-amino acid motif substituted at the 2-position can be prepared in moderate to good yields by Negishi as well as Suzuki-Miyaura cross-couplings as the key synthetic steps. The reaction sequence involves N-protection (ethoxymethylation), whereby both generated regioisomers could be separated by column chromatography, and selective 2-lithiation. Subsequent transmetalation to zinc or an iodine quench affords reactants suitable for Pd-catalyzed Negishi and Suzuki-Miyaura reactions with (hetero)aromatics.