Cycloadditions are a type of chemical reaction where two or more unsaturated molecules combine to form a cyclic structure. This process typically involves the formation of new carbon-carbon bonds, resulting in a ring-shaped compound. Cycloadditions are important in organic chemistry for synthesizing complex molecules and are often used in the development of pharmaceuticals and materials. One well-known example of cycloaddition is the Diels-Alder reaction, which involves a diene and a dienophile reacting to form a six-membered ring. This reaction is valued for its ability to create multiple bonds and functional groups in a single step, making it a powerful tool for chemists in constructing intricate molecular architectures.