Metal-mediated cleavage of unsaturated C-C bonds

•Comprehensive review of metal-mediated cleavages of unsaturated C-C bonds in alkenes, alkynes and aromatic molecules.•Overview of stoichiometric and catalytic C-C activations of C-C bonds by soluble metal complexes.•Survey of oxidative and non-oxidative C-C cleavage of unsaturated C-C bonds. Cleavage of C-C bonds by transition metal complexes is a fascinating organometallic transformation that underpins a range of industrial processes and offers exciting opportunities for development new synthetic methods through reconstruction of hydrocarbon framework. Various examples of single C-C bond cleavage have been extensively covered in recent literature, but equally rich chemistry of metal-mediated scission of unsaturated C-C bonds has not been comprehensively surveyed so far. This review aims to fill this gap and highlights stoichiometric and catalytic reactions involving metal-induced full cleavage of unsaturated C-C bonds in alkenes, alkynes and aromatic systems.