Rapid and column-chromatography-free peptide chain elongation via a one-flow, three-component coupling approach

Short peptides are extremely important as drugs and building blocks for the syntheses of longer peptides. Both solid- and liquid-phase peptide syntheses suffer from a large number of synthetic steps, high cost, and/or tedious purification. Here, we developed a rapid, mild, inexpensive, and column-chromatography-free peptide chain elongation via a one-flow, three-component coupling (3CC) approach that is the first to use alpha-amino acid N-carboxy anhydrides (alpha-NCAs) both as electrophiles and nucleophiles. We demonstrated the high-yielding and column-chromatography-free syntheses of 17 tripeptides, as well as a gram-scale synthesis of a tripeptide. The total synthesis of beefy meaty peptide was achieved by repeating the 3CC approach with the addition of only one column chromatographic purification. We also demonstrated a one-flow tripeptide synthesis via in situ preparation of alpha-NCA starting from three readily available protected amino acids. With this study, we achieved dramatic reductions in both time and cost compared with typical solid-phase synthesis.

Automated summary

Short peptides play a crucial role in drug development and the synthesis of longer peptides. Traditional methods of solid- and liquid-phase synthesis are time-consuming, expensive, and require tedious purification. In this study, we introduce a novel approach called one-flow, three-component coupling (3CC) that utilizes alpha-amino acid N-carboxy anhydrides (alpha-NCAs) as both electrophiles and nucleophiles. We successfully synthesized 17 tripeptides and achieved gram-scale synthesis of a tripeptide without the need for column chromatographic purification. By preparing alpha-NCA in situ from readily available protected amino acids, we achieved significant reductions in time and cost compared to solid-phase synthesis.