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.