Used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS) methods. It serves as a building block for introducing modified phenylalanine residues into peptide chains. The Fmoc group provides protection for the amino group during synthesis, ensuring selective reactions. The 4-methyl substitution on the phenyl ring can influence the peptide's structure and interactions, making it valuable in designing peptides with specific biological activities or stability. Commonly applied in pharmaceutical research, drug development, and the study of peptide-based therapeutics.