C–H Functionalizations by Palladium Carboxylates: The Acid Effect

Finding
optimal reaction conditions is usually complex, requires
many experiments, and is therefore demanding in terms of human, financial,
and environmental resources. This work provides a simple workflow
for easier design of popular palladium-catalyzed C–H functionalization
reactions, where the active palladium catalysts contain carboxylate
ligands. The key factor for optimizing reaction conditions is to find
a balance between two opposing effects of the carboxylic acid in the
reaction mixture: generation of more reactive palladium catalyst versus
deactivation of a substrate by its protonation.