4-Substituted Prolines: Useful Reagents in Enantioselective Synthesis and Conformational Restraints in the Design of Bioactive Peptidomimetics

摘要

Among the substituted prolines, 4-substituted ones deserve particular attention. The ring conformation and the puckering preference of the prolyl ring are strongly affected by insertion of the substituent, and a great number of peptides containing these noncanonical amino acids have been investigated in the last five years. Moreover, the distance of the substituent from the functions involved in peptide chain formation causes minimal steric hindrance, thus offering the opportunity for conjugation with other chemical groups with little perturbation of the peptide chain.