Topic overview

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Oxidative addition commonly raises a metal’s oxidation state and coordination number, while its mechanism depends in part on the substrate bond. Migratory insertion moves a ligand onto an unsaturated group such as CO, often extending a carbon chain without changing the metal’s oxidation state. β-Hydride elimination transfers a β-hydrogen to the metal and forms an alkene; it requires an available β-H and a vacant cis site. Reductive elimination couples two cis ligands and lowers the metal’s oxidation state. Together, these steps help explain bond formation and chain growth in catalytic cycles. The topic also introduces σ-bond metathesis as a distinct pathway that can activate C–H bonds without changing oxidation state.