Ammonium‐Anchored Palladium‐NHC Complex on Polystyrene Resin: A Highly Reactive Catalyst for the Mizoroki‐Heck Reaction**

Abstract A polystyrene supported palladium complex was prepared via quaternization of an amine functionalized NHC palladium complex with Merrifield resin. The material was characterized by multiple spectroscopic and microscopic techniques and applied in the Mizoroki‐Heck reactions. Upon immobilization, the catalytic activity of the Pd‐NHC increased significantly, which even allowed gram‐scale conversions at ppm [Pd] loadings. Kinetic, hot filtration and poisoning tests indicated that the material only functioned as a pre‐catalyst. Soluble Pd(0) species were generated under the catalytic condition as the real catalysts, which were re‐capturable to the ammonium‐NHC functionalized resin support, allowing catalytic recycling for seven times.