Carbonyl Sulfide-Mediated Synthesis of Peptides with Amino Acid Ionic Liquids

Carbonyl sulfide (OCS), the component of volcanic emission, has been found to induce the condensation of amino acids under simulated primordial earth conditions. However, the applications of OCS in peptide chemical synthesis is still limited by their heterogeneities and low efficiencies. We herein report an OCS-mediated approach for solid-phase peptide synthesis using amino acid ionic liquids as recyclable reactants. The coupling reactions required no base and solvent and was completed in minutes at room temperature. The applicability and sustainability of this approach were demonstrated by the facile syntheses of peptides with remarkably high yields.