Palladium-Catalyzed Cascade Cyclization/Alkynylation Reactions

Abstract

Palladium-catalyzed cascade cyclization reactions have witnessed significant improvements in recent years. Among them, palladium-catalyzed cascade cyclization/alkynylation are especially attractive, which can assemble structurally diverse monocyclic, bicyclic, fused polycyclic, and spirocyclic skeletons with excellent chemoselectivities. In this Minireview, palladium-catalyzed cascade cyclization/alkynylation have been summarized and discussed in detail with focus on oxypalladation and aminopalladation-initiated cascade cyclization, intramolecular Heck-type cascade cyclization, carbocyclizations, cascade cyclizations, and other types of cascade cyclization reactions. Some significant and representative synthetic methodologies and their synthetic applications and reaction mechanisms have also been described.

Keywords: alkynes; alkynylation; cyclization; palladium; synthetic methods.