Organolithium compounds are a class of chemical compounds that contain a carbon-lithium bond. They are typically formed by the reaction of lithium with organic halides, resulting in a highly reactive species. These compounds are known for their strong nucleophilic properties, making them valuable in organic synthesis for creating new carbon-carbon bonds. Due to their reactivity, organolithium compounds are often used as reagents in various chemical reactions, including lithiation and cross-coupling reactions. They can also serve as intermediates in the production of pharmaceuticals and other complex organic molecules, highlighting their importance in the field of organic chemistry.