Ruthenium-Catalyzed Decarboxylative Direct 2-Pyridination of α,β-Unsaturated Carboxylic Acids

We report a ruthenium-catalyzed decarboxylative direct mono-2-pyridination of α,β-unsaturated carboxylic acids, offering a selective method for synthesizing 2-(1-arylalkenyl)pyridines. Under redox-neutral conditions, the reaction demonstrates broad substrate scope, high functional group tolerance, and significant potential for further derivatization. Mechanistic studies reveal that selective activation of the allylic C(sp³)-H bond, directed by the pyridine group, underpins the observed mono-2-pyridination. This work provides an efficient and selective strategy for the catalytic decarboxylative transformation of α,β-unsaturated carboxylic acids, expanding the toolbox for functionalizing pyridine derivatives.