The activation of multiple bonds is one of the central reactivity patterns in transition-metal catalysis. Selectivity is a crucial issue in terms of the connection of the atoms (chemoselectivity) and the steric arrangement of the atoms (stereoselectivity) in the product. If out of several possible products only one is formed, transition-metal catalysis will contribute to the responsible use of resources in the sense of green chemistry. A high catalytic activity is important, too. The discovery of new direct chemical transformations, which previously could only be achieved by multistep synthesis, is highly innovative.