Collaborative Interaction of Carbon-Carbon Unsaturated Bond Groups with Transition-metal Catalysts for C-H Bond Functionalization

Alkynes, alkenes, and thiophenes are found to behave as a directing group for C-H bond activation by a transition-metal catalyst. This collaborative interaction led to the discovery of not only simple intramolecular cyclizations but also carbon-carbon bond formation or annulation reactions with other reactants involving such unsaturated bond-directing groups. This highlight review discusses the recent progress in this sort of novel synthetic tools.