Benchmarking Immobilized Di- and Triarylphosphine Palladium Catalysts for Continuous-Flow Cross-Coupling Reactions: Efficiency, Durability, and Metal Leaching Studies

Leaching resistance and recyclability, in addition to efficiency, are key parameters which constrain the choice of a catalyst for performing metal-catalyzed cross-coupling reactions in continuous-flow mode. Comparison of commercially available immobilized catalysts is often difficult because literature data are typically obtained under a wide range of reaction conditions. Here we present a comparative investigation on some of the most common immobilized phosphine-based Pd catalysts, namely Pd Tetrakis (polymer bound), Fiber Cat 1001, En Cat TPP30, and SiliaCat DPP-Pd. The efficiency, recyclability, and leaching resistance of each of the catalysts has been carefully investigated under a standard set of conditions as well as a selection of literature-based protocols. The data presented herein enable a direct comparison of these catalysts and provide further insights into the leaching phenomena of these types of ligand-based palladium catalysts.