An atomically precise Au(DPPF)PPh cluster catalyst for N-hydroformylation of amines.

Heterogeneous catalysis is crucially important for the well-being of society, and new catalysts are continuously discovered to improve chemical processes. Here we report a catalytic system based on an atomically precise Au(DPPF)PPh (DPPF = bidentate 1,1'-bis(diphenylphosphino)ferrocene) cluster, where two functional units are combined into one catalyst for N-hydroformylation of pyrrolidine with CO and H. The two units execute their respective roles, including two types of ligands that mediate the structural framework and further reinforce the catalytic stability of the cluster, and a metal core consisting of ten gold atoms that are all potentially active sites participating in the hydrogenation of CO toward the key intermediate, such as formic acid. Sequentially, formylation proceeds a relay migration of protons along a proposed transition state originating from the intermediate and pyrrolidine, thereby breaking the N-H bond and constructing the C-N bond. The synergy between the active sites and the neighbouring environment therefore enables optimal activity and stability of the cluster catalyst, outperforming most catalysts reported under comparable conditions.