Used as a highly reactive building block in medicinal chemistry, particularly in the development of covalent inhibitors. Its strained oxetane ring enhances binding affinity and metabolic stability in drug candidates. The sulfonyl fluoride group enables selective covalent modification of proteins, making it valuable in chemical biology for target identification and labeling. It is also employed in sulfur fluoride exchange (SuFEx) click chemistry, a robust method for assembling molecules under mild conditions, useful in drug discovery and bioconjugation.