Single atoms catalyze Suzuki reactions

As effective as the palladium-catalyzed Suzuki reaction is for forming carbon-carbon bonds, researchers see room for improvement. Homogeneous palladium catalysts can be tough to separate from products, and fixing the problem by attaching catalysts to solid supports can lead to problematic metal leaching. Meanwhile, heterogeneous palladium nanoparticle catalysts on solid supports rarely catalyze the reaction efficiently. Now, Javier Pérez-Ramírez of ETH Zurich and colleagues suggest another route to Suzuki chemistry: single-atom catalysis (Nat. Nanotechnol. 2018, DOI: 10.1038/s41565-018-0167-2). Multiple labs have demonstrated catalysis of over 10 reactions by isolated atoms supported on a solid. This team anchored palladium atoms to nanometers-thick sheets of exfoliated graphitic carbon nitride, which contain metal-stabilizing nitrogen-rich sites. The catalyst performed a Suzuki reaction in flow for 13 hours with negligible metal leaching. Calculations from coauthor Núria López of the Institute of Chemical Research of Catalonia suggest that the palladium atoms continuously adapt their coordination within the same site on the carbon nitride as the reaction progresses, minimizing energy at each step. Experimentally verifying that result will be challenging, the authors say, but improvements to catalyst-monitoring spectroscopy techniques could help. The authors plan to test other reactions and metals with their system as well as launch a company to market the catalysts.