(652a) Investigating Reaction Mechanisms Using Synthetic and Spectroscopic Tools

The manufacture of fine chemicals and pharmaceuticals benefits from developing new catalysts to convert basic building blocks into complex compounds via atom efficient chemistry. Recent catalytic discoveries have identified molecular catalysts for upgrading dienes and acrylates through cobalt-catalyzed heterodimerization, but these catalysts produce limited yield with low turnover numbers (TONs). We use reaction progress kinetic analysis to investigate the reaction mechanism. Importantly, we identified that the reaction is first order in the diene and zero order in the acrylate. Additionally, the investigations revealed that the catalyst is cationic Co(I) that forms during the initial stages of the reaction. Through tuning the reaction conditions, we were able to increase the TON by an order of magnitude while maintaining high catalytic activity. The analysis inspired the design of new catalysts that were highly active and selective.