Synthesis of Sulfur Heterocycles by Palladium‐Catalyzed Cyclization

The minireview is aimed at giving an overview on palladium‐catalyzed cyclization methods for the synthesis of important sulfur heterocycles, including thiophenes, benzothiophenes, benzothiazoles, and sulfur‐containing polycyclic systems. The minireview is organized into several sections based on the kind of reactivity leading to the sulfur heterocycle, namely: Pd‐catalyzed cyclization of aryl and vinyl halide derivatives; Pd‐catalyzed cyclization by C—H activation; Pd‐catalyzed cyclization of olefinic substrates; Pd‐catalyzed cyclization of acetylenic substrates; Pd‐catalyzed carbonylative cyclization; cyclization by Pd‐catalyzed ring opening—ring closure. The review covers Pd‐catalyzed S ‐cyclizations as well as transformations in which the sulfur atom lies within the chain undergoing annulation.