Synfacts 2005(1): 0146-0146  
DOI: 10.1055/s-2005-916012
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Enantioselective Friedel-Crafts Alkylations of α,β-Unsaturated 2-Acyl Imidazoles

Contributor(s): Hisashi Yamamoto, Matthew B. Boxer
D. A. Evans*, K. R. Fandrick, H. Song
Harvard University, Cambridge, USA
Further Information

Publication History

Publication Date:
21 September 2005 (online)

Significance

Although there are examples of asymmetric Friedel-Crafts alkylations, the use of the α,β-unsaturated 2-acyl imidazoles as acceptor is a new finding. This substrate-catalyst combination allows the reaction to be performed at 0 °C, providing high enantioselectivities with low catalyst loadings. The resulting 2-acyl imidazole residue can be transformed into various carboxylic acid derivatives via methylation and nucleophilic additions.