Metal-ligand cooperation at tethered π-ligands

Metal-ligand cooperativity in homogeneous catalysis is emerging as a powerful tool for the design of efficient transition-metal catalysts. This perspective highlights recent advances in the use of neutral pi-coordinating ligands, tethered to a transition-metal center by other donor ligands, as cooperative reaction centers. The state-of-the-art organometallic complexes, including pi-coordinating ligands originating from C = C, C = E (E = O, N) and boron containing moieties, are described here, with special attention on their specific reactivity. Geometric and electronic aspects of ligand design and their influence on the coordination mode and reactivity of the pi-system are discussed.