Fmoc-(S)-2-Tetrahydroisoquinoline acetic acid is widely used in peptide synthesis as a protecting group for amino acids. Its Fmoc group ensures selective deprotection under mild basic conditions, making it valuable in solid-phase peptide synthesis (SPPS). The compound is particularly useful in constructing complex peptides and proteins, especially those requiring precise stereochemistry. It is also employed in the development of peptide-based drugs, where its stability and compatibility with various coupling reagents are advantageous. Additionally, it finds applications in the synthesis of peptidomimetics and bioactive molecules, contributing to advancements in medicinal chemistry and drug discovery.