5-Substituted -Aminoimidazolone Peptide Mimic Synthesis by Organocatalyzed Reactions of Azopeptides and Use in the Analysis of Biologically Active Backbone and Side-Chain Topology.

Fifteen -aminoimidazolone (Nai) dipeptides having a variety of 5-position side-chain groups were synthesized by regioselective proline-catalyzed reactions of azopeptide and aldehyde components followed by acid-mediated dehydration of an aza-aspartate semialdehyde intermediate. The introduction of 5-aryl-Nai dipeptides into cluster of differentiation 36 receptor (CD36) peptide ligands has provided insight into the conformation responsible for binding affinity and anti-inflammatory activity.