Highly efficient coupling of β-substituted aminoethane sulfonyl azides with thio acids, toward a new chemical ligation reaction

(Chemical Equation Presented) A highly efficient coupling of protected β-substituted aminoethane sulfonyl azides with thio acids is reported. In the case of peptide thio acids, this method encompasses a new chemoselective ligation method. Furthermore, the resulting α-amino acyl sulfonamides can be alkylated with suitable electrophiles to obtain densely functionalized sulfonamide scaffolds.