Click Chemistry Aided Synthesis of 1,4-Substituted 1,2,3-Triazole Based N-Fmoc Protected -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. Keywords: Click reaction, 1,2,3-Triazole, 3 + 2 cycloaddition, unnatural amino acid, Fmoc-chemistry