Allylpalladium(II) chloride dimer is an organopalladium catalyst widely used in organic synthesis, particularly for palladium-catalyzed allylic substitutions such as the Tsuji-Trost reaction, enabling the formation of carbon-carbon and carbon-heteroatom bonds via allylic alkylation or amination. It is essential in the synthesis of complex organic molecules, including pharmaceuticals, natural products, and fine chemicals. Its ability to promote regioselective and stereoselective transformations makes it valuable for creating intermediates in drug development, agrochemicals, and material science. Additionally, it is applied in asymmetric catalysis and the functionalization of polymers.