Fmoc-4-Iodo-L-phenylalanine is widely used in peptide synthesis as a building block, particularly in solid-phase peptide synthesis (SPPS). The Fmoc group serves as a protecting group for the amine functionality, allowing for selective deprotection and subsequent coupling of amino acids. The iodine atom on the phenyl ring provides a handle for further functionalization through cross-coupling reactions, such as Suzuki or Sonogashira couplings, enabling the introduction of diverse chemical moieties into peptides. This makes it valuable in the development of peptide-based drugs, bioconjugates, and probes for biochemical studies. Additionally, its incorporation into peptides can enhance their stability and binding properties, making it useful in the design of peptide mimetics and therapeutics targeting specific biological pathways.