Used as a building block in the synthesis of pharmaceuticals and bioactive compounds due to its structural similarity to tyrosine. Its phosphonic acid group allows for strong binding to metal ions and enzymes, making it valuable in the design of enzyme inhibitors, particularly for kinases and phosphatases. Also employed in materials science for surface modification of metal oxides, where it forms stable monolayers useful in sensors and molecular electronics. Its hydroxyl group enables further functionalization, supporting use in creating libraries for drug discovery and in the development of novel catalysts.