A traceless approach to amide and peptide construction from thioacids and dithiocarbamate-terminal amines

Abstract

A novel and traceless strategy has been devised that allows a coupling of thioacids and dithiocarbamate-terminal amines. This strategy had been assumed to be dependent on the attachment of a functional equivalent of a cysteine side chain in earlier native chemical ligation approaches. This approach enables the traceless removal of CS₂ to directly generate the desired amide bond and is compatible with a range of unprotected side chains of amino acid. The ability to produce amide or peptides by a traceless removal of the auxiliary is a significant virtue of the method. Meanwhile, the application of this new peptide-bond-forming reaction to the synthesis of novel endomorphin (EM) derivatives with various binding potencies was realized.