Development of and Recent Advances in Pd-Catalyzed Decarboxylative Asymmetric Protonation.

Decarboxylative asymmetric protonation (DAP) is a mild and efficient synthetic tool for the catalytic asymmetric formation of tertiary stereocenters adjacent to a carbonyl group. The development of the methodology from the initial racemic report to recent asymmetric examples is summarized. The discovery of an enantiodivergent Pd-catalyzed DAP, in which the choice of the achiral proton source determines the stereochemical outcome, is highlighted. Furthermore, the mechanism of Pd-catalyzed DAP, investigated since the initial report, is also discussed.