Ruthenium-Catalyzed C-H Functionalization of Benzoic Acids with Allyl Alcohols: A Controlled Reactivity Switch between C-H Alkenylation and C-H Alkylation Pathways.

A highly selective and switchable ruthenium-catalyzed ortho C-H alkylation and C-H alkenylation of benzoic acids with allyl alcohols is reported. A complete switch in selectivity is achieved upon tuning the reactivity of the organometallic intermediate in the carboxylate-directed C-H activation to provide access to highly useful motifs such as 2-alkylbenzoic acids and phthalides.