Synthesis of retro-inverso peptides employing isocyanates of Nα-Fmoc-amino acids/peptide acids catalyzed by DMAP

The Goldschmidt–Wick type reaction between isocyanates of Nα-Fmoc-amino acids/peptide acids and Nα-Boc-/Z-/Bsmoc-amino acids catalyzed by DMAP leads to the incorporation of a reversed peptide bond. It was found to be a simple, efficient and clean reaction. All the retro-inverso peptides made were obtained as crystalline compounds in 70–92% yields.