Manganese-Catalyzed Ortho -C–H Alkenylation of Aromatic Ketones

High Resolution Image Download MS PowerPoint Slide Ortho -C–H alkenylation of aromatic ketones is a key transformation for bioactive molecules and functional materials, but all existing methods rely on scarce noble metals, hindering industrial applications. Herein, we report the first manganese-catalyzed ortho -C–H alkenylation of aromatic ketones with commercial acrylates. Using MnBr(CO) 5 as the precatalyst, the reaction proceeds under mild aqueous conditions with broad substrate scope, scalable to 10 mmol, and allows tunable mono/bis-alkenylation via acrylate stoichiometry. Mechanistic studies support an electrophilic C–H metalation pathway, and the products can be readily derivatized to isoquinoline frameworks. This work provides a sustainable alternative and enables manganese catalysis with weakly coordinating directing groups.