Cu-Catalyzed Esterification Reaction via Aerobic Oxygenation and C-C Bond Cleavage: An Approach to α-Ketoesters

The Cu-catalyzed novel aerobic oxidative esterification reaction of 1,3-diones for the synthesis of alpha-ketoesters has been developed. This method combines C-C sigma-bond cleavage, dioxygen activation and oxidative C H bond functionalization, as well as provides a practical, neutral, and mild synthetic approach to alpha-ketoesters which are important units in many biologically active compounds and useful precursors in a variety of functional group transformations. A plausible radical process is proposed on the basis of mechanistic studies.