Click chemistry aided synthesis of 1,4-substituted 1,2,3-triazole based N-Fmoc protected epsilon-amino acids: isolation, characterization and synthesis of novel triazole based unnatural amino acids.

A new class of 1,4-substituted 1,2,3-triazole-based unnatural amino acids is demonstrated by employing click reaction between N-Fmoc amino alkyl azides and propiolic acid. The resulting unnatural amino acids were isolated and then subjected to Fmoc deprotection to isolate 1,2,3-triazole based amino acids as stable solids. These new class of molecules were also used for chain extension from both N- and C-terminals to synthesize dipeptidomimetics bearing 1,2,3-triazole moiety in the backbone.