Used as a key building block in medicinal chemistry, particularly in the design of bioisosteres. Its rigid, three-dimensional structure helps improve metabolic stability and solubility in drug candidates. Commonly employed to replace phenyl or other planar rings, enhancing pharmacokinetic properties. Widely applied in the development of CNS drugs, agrochemicals, and PET tracers due to its favorable steric and electronic characteristics. Also utilized in materials science for creating high-performance polymers with unique thermal and mechanical properties.