Alkynes in Multicomponent Synthesis of Heterocycles

Alkynes are highly versatile functionalities for multicomponent syntheses of heterocycles. Although they can be considered as electron‐rich functionalities displaying σ‐ and π‐nucleophilic reactivity as well as they can participate in many organometallic transformations, alkynes with electron‐withdrawing substituents are excellent electro‐, dipolaro‐, and dienophiles in multicomponent reactions furnishing heterocycles. It is particularly interesting that acceptor‐substituted alkynes, such as ynones, can be generated catalytically and they can be directly used in multicomponent reactions. Most recent contributions in the field of alkynes as reactants in multicomponent syntheses of heterocycles are discussed in this chapter.