Akagawa K, Sen J, Kudo K * The University of Tokyo, Japan
Peptide-Catalyzed Regio- and Enantioselective Reduction of α,β,γ,δ-Unsaturated Aldehydes.
Angew. Chem. Int. Ed. 2013;
52: 11585-11588
Key words
α,β,γ,δ-unsaturated aldehydes - Hantzsch esters - asymmetric transfer hydrogenation - peptide catalysis
Significance
The amphiphilic resin-supported peptide 1 catalyzed the regio- and enantioselective transfer hydrogenation of (2E,4E)-α,β,γ,δ-unsaturated aldehydes 2 with a Hantzsch ester to give the corresponding aldehydes 3 in 47–87% yield with 87–99% ee (14 examples, eq. 1).
Comment
In the hydrogenation of the mixture of (2E,4E)-2b and (2Z,4E)-2b, aldehyde 3b was obtained in 71% yield with 97% ee (eq. 2). The authors have previously reported the asymmetric transfer hydrogenation of α,β-unsaturated aldehydes with a Hantzsch ester in the presence of resin-supported peptides (Org. Lett. 2008, 10, 2035; Tetrahedron: Asymmetry 2009, 20, 461).
