Development of novel chemoselective ligation techniques for protein chemical synthesis

A novel strategy has been devised that allows a ligation of of thioacids and imidazolyl urea activated amines under aqueous conditions. This approach enables the traceless removal of imidazole and CO2 to directly generate the desired amide bond without affecting the side chain reactive side chain functional groups on the peptide chain. Meanwhile, the novel synthesis of peptide thioacid is also reported.