Silk−Fibroin‐Supported Palladium Catalyst for Suzuki‐Miyaura and Ullmann Coupling Reactions of Aryl Chlorides

Recently, we have reported the preparation of a silk fibroin-supported Palladium catalyst (Pd/SF) and its use in Suzuki-Miyaura cross-coupling aryl iodides. Since synthetic applicability structural features are still far from being fully explored, deeper investigation is here. Pd/SF tested as for Ullmann coupling reactions chlorides, H2O/EtOH solvent mixture under atmospheric conditions. Starting analysis products promoted poly-haloarenes, can hypothesize existence catalytic pockets where monoatomic palladium species form stable complexes with SF. To shed light on this hypothesis, characterized by Wide-Angle X-ray Scattering (WAXS) analysis, which supports supposition pockets. Finally, using computational model developed Molecular Mechanic Energy Minimization estimated dimension pocket (about 15 Å), good agreement experimental results.