Construction of Thioamide Peptide via Sulfur-Involved Amino Acids/Amino Aldehydes Coupling

A sulfur-involved ligation for thioamide quasi-peptides was developed via amino acids and amino aldehydes coupling. The key to the transformation was the chelation of copper with imines for chiral activation and fixation. In this environment, linear polysulfur decreased the alkalinity of single sulfur anions to prevent racemization caused by the interaction between sulfur and sodium sulfide. Dipeptides, tripeptides, tetrapeptides, and the linkage between the drug and amino acids were successfully obtained.

Automated summary

A sulfur-involved ligation for thioamide quasi-peptides was developed via coupling of amino acids and amino aldehydes, with chelation of copper with imines for chiral activation and fixation being key to the transformation. Linear polysulfur was used to decrease the alkalinity of single sulfur anions, preventing racemization caused by interaction with sodium sulfide, resulting in successful synthesis of dipeptides, tripeptides, tetrapeptides, and drug-amino acid linkages.