Enantioselective Allenoate Additions to Imines
B. J. Cowen, L. B. Saunders, S. J. Miller*
Yale University, New Haven, USA
25. Mai 2009 (online)
A peptide-catalyzed enantioselective allenoate addition to N-acyl imines is reported. Among different examined catalysts, all capable to adopt β-turn conformations, a peptide which is composed of a phenylalanine, an amino-isobutyric acid, a proline and a pyridylalanine (Pal) moiety proved to be the most beneficial species. Variously substituted aromatic and aliphatic imines react with allenoates furnishing the products in satisfactory yields and good enantioselectivities.