Organochalcogen ligands and their palladium(II) complexes: Synthesis to catalytic activity for Heck coupling

Heck cross coupling reactions have been catalyzed with several palladium(II)-complexes of organochalcogen ligands. The complexes applied in molecular and tethered forms appear to be dispensers of catalytically active species, but this aspect has not been thoroughly looked at in all cases. The thermal stability, air and moisture insensitivity and ease of handling and synthesis have made them viable alternatives to phosphine/carbene based Pd-catalysts. This review covers developments from the design of organochalcogen ligands and their palladium(II)-complexes to the applications of these complexes in catalyzing Heck reactions.