Computational Insights into Divergent Pd-Catalyzed Oxidations with Oxone: Unveiling Dual Wacker and Oxo-Hydroxylation Pathways.

Pd-(II)-catalyzed Wacker oxidation represents a robust and attractive route to methyl ketones from terminal alkenes in modern organic synthesis. In this work, we report a tunable oxidation system that employs oxone (potassium peroxymonosulfate) as a green oxidant and di-(pyridin-2-yl)-amine as an effective ligand. Notably, the presence of water triggers a mechanistic divergence from the conventional Wacker-type oxidation to a previously unrecognized radical pathway, enabling selective access to α-hydroxy ketones. Combined experimental and computational studies confirm that methyl ketones are generated via the classical 1,2-hydride migration, whereas α-hydroxy ketones arise through a radical mechanism pathway followed by an OAc--assisted intermolecular proton transfer. This work provides fundamental insights into water-mediated radical pathways in Pd-catalyzed oxidations and establishes a strategy for selective functionalization of terminal alkenes.