Transition-Metal-Mediated Cleavage and Activation of C-C Single Bonds

The activation and cleavage of CC single bonds mediated by transition metal complexes is one of the most challenging reactions, both practically and in terms of understanding, in the field of metal organic chemistry. In this review the fundamental reactions oxidative addition, beta-carbon elimination, retro-allylation, and radical cleavage so far successfully applied for this transformation are discussed in terms of their mechanisms, their intrinsic problems, and their published examples, which are still fairly rare. Decarbonylation, as another fundamental reaction, is only touched briefly. This group of reactions is today poised to set aside its shadow existence as an exotic reaction class. Meanwhile the number of catalytic and even enantioselective processes involvingCC single bond cleavage is slowly increasing, although the substrates used in these reactions are still limited to quite special connection patterns. The basic challenges for the future and the paradigms concerning this reaction are presented.