A³ Coupling Reaction in the Synthesis of Heterocyclic Compounds

In recent years, the transition‐metal catalyzed three‐component coupling of an aldehyde, an alkyne and an amine, commonly called A 3 coupling has become a powerful tool in organic synthesis. The aim of this review is to give a general overview of A 3 coupling utility in the synthesis of heterocycles, highlighting the variety of compounds that can be directly accessed from single reactions. The diverse A 3 coupling based methodologies that have been developed for the synthesis of N,O,S ‐heterocycles are presented, emphasizing the influence of the reaction conditions and the use of additional reagents in the outcome of the transformations. magnified image