Cross-coupling reactions occur when two reagents, both with activating groups, react together with a metal catalyst to form a new covalent bond, driven by loss of the activating groups. Pd is the principle catalyst metal. The 2010 Nobel Prize in Chemistry was awarded to Richard Heck, Ei-ichi Negishi, and Akira Suzuki for their contributions to the development of Pd-catalyzed C-C bond forming reactions.