Palladium-catalyzed heterocyclization: a carbon-centered approach

Heterocycles are some of the most important and widely used motifs in synthetic and medicinal chemistry. It is therefore not surprising that the synthesis of heterocycles is a rich area of chemical research. Catalytic heterocyclization that makes use of heteroatomic nucleophiles, such as oxygen and nitrogen, is one such powerful strategy. This Focus Review considers an alternative approach that uses carbon-based nucleophiles that are generated during palladium-catalyzed heterocyclization reactions. This complimentary method allows access to a range of useful and otherwise-inaccessible targets. Occurring through a range of different mechanisms, the utility of this approach can be seen in the wide range of transformations that can be undertaken, along with its repeated application in the synthesis of complex molecules.