Investigating the Versatility of Transition Metal Complexed Polymer Catalysts

Polymeric catalysts have emerged as a versatile framework for enhancing a wide range of chemical reactions essential to organic synthesis. By combining features of both enzymes and small molecule catalysts, these materials can form solvophobic pockets while retaining the synthetic versatility of small molecules.  We have previously synthesized a library of polymer catalysts containing a novel triphenylphosphine acrylamide monomer (TPPAm). When complexed with palladium, these polymeric catalysts have demonstrated superior reactivity compared to small molecule alternatives at mild reaction conditions for the Suzuki-Miyaura cross coupling reaction. My research contributions began with the development of a bidentate phosphine monomer (TPPAm), which can bind to the palladium metal center without crosslinking the polymer. BisTPPAm provided critical insights into the effects of cross-linking on reaction kinetics for the Suzuki-Miyaura cross coupling, showing high reactivity  50:50 DMF:H₂O solvent mixtures, but decreasing reactivity as the solvent became more aqueous. Additionally, I expanded the scope of TPPAm-containing polymer catalysts beyond the Suzuki-Miyaura cross-coupling, investigating their performance in three additional reactions: the Pd-catalyzed Sonogashira reaction, a Pt-catalyzed amination of allyl alcohol, and a Rh-catalyzed conjugate addition. Kinetic studies of these reactions establish a foundation for further optimization of TPPAm-based polymer catalysts.