This chiral imidazolidinone hydrochloride, often referred to as MacMillan's catalyst, is primarily employed as an organocatalyst in asymmetric synthesis. It facilitates enantioselective reactions such as Diels-Alder cycloadditions, Friedel-Crafts alkylations, and other carbon-carbon bond formations, enabling the production of complex chiral molecules with high stereocontrol. This makes it essential for the development of pharmaceuticals, particularly in synthesizing active pharmaceutical ingredients (APIs) for neurological disorders, cardiovascular diseases, and other therapeutic areas. The hydrochloride salt enhances its solubility in polar solvents, improving handling and reaction efficiency. It is also used in academic and industrial research to explore stereoselective mechanisms and innovative synthetic pathways.