Akagawa K, Takigawa S, Nagamine IS, Umezawa R, Kudo K * University of Tokyo, Japan
Peptide-Catalyzed Diastereo- and Enantioselective Cyclopropanation of Aromatic α,β-Unsaturated Aldehydes.
Org. Lett. 2013;
15: 4964-4967
Key words
resin-supported peptides - asymmetric cyclopropanation - α,β-unsaturated aldehydes
Significance
The amphiphilic resin-supported peptide 1 catalyzed the diastereo- and enantioselective cyclopropanation of aromatic α,β-unsaturated aldehydes 2 with dimethylphenacylsulfonium bromide in the presence of NaHCO3 to give the corresponding cyclopropanes 3 in 83–88% yield with 98–99% ee and 92–97% diastereoselectivity (9 examples, eq. 1). In the formation of 3g, the catalyst was recovered by filtration and reused five times without significant loss of its catalytic performance (1st reuse: 87% yield, 99% ee, 94% diastereoselectivity; 5th reuse: 83% yield, 99% ee, 95% diastereoselectivity).
Comment
The authors have previously reported the preparation of a series of amphiphilic resin-supported peptides and their application to asymmetric hydrogenation (Org. Lett. 2008, 10, 2035), asymmetric Friedel–Crafts-type alkylation (Adv. Synth. Catal. 2012, 354, 1280) and asymmetric Michael addition (Angew. Chem. Int. Ed. 2012, 51, 12786).
