Suzuki, Heck, and copper-free Sonogashira reactions catalyzed by 4-amino-5-methyl-3-thio-1,2,4-triazole-functionalized polystyrene resin-supported Pd(II) under aerobic conditions in water

4-amino-5-methyl-3-thio-1,2,4-triazole-functionalized polystyrene resin-supported Pd(II) complex was found to be an efficient catalyst in the palladium-catalyzed Suzuki–Miyaura coupling reactions of aryliodides and bromides, Mizoroki–Heck reactions of aryliodides and bromides, and copper-free Sonogashira reactions of aryliodides and bromides in water. Under appropriate conditions, all of these reactions give the desired products in moderate to excellent yields. The catalyst is air-stable and easily available. The palladium catalyst is easily separated, and can be reused for several times without a significant loss in its catalytic activity.