Formal Decarbonylation of 1,2-Diketones Enabled by Synergistic Catalysis of Lewis Acid–Base Pairs and Redox Properties in CeO2

Various decarbonylation reactions via oxidative addition of carbonyl compounds to metal catalysts can be applied to late-stage modification and have been actively studied to date; however, several inherent problems derived from the oxidative addition are difficult to solve, such as toxic CO production, deactivation of catalysts by CO adsorption, intolerance of some functional groups, or air-sensitivity of catalysts. In this context, formal decarbonylation, which eliminates CO as other compounds without involving oxidative addition, is attractive but hardly reported, especially using heterogeneous catalysts. Herein, formal decarbonylation of diaryl 1,2-diketones to afford monoketones using CeO2 as a reusable heterogeneous catalyst and O2 in the air as the terminal oxidant was developed, generating CO2 as the only byproduct. The results revealed that the reaction was enabled by the synergistic catalytic effect of the Lewis acid–base pairs and redox properties in CeO2.