Monocarboxylation and Intramolecular Coupling of Butenylated Arenes via Palladium-Catalyzed C–H Activation Process

A novel and practical reaction for the direct intramolecular oxidative coupling of butenylated arenes is reported. With the catalysis of Pd(OAc)2, reactions of various butenylated arenes and carboxylic acids with Selectfluor reagent in CH3CN solution afforded the corresponding monocarboxylation/cyclization products in good yields under mild conditions. This research demonstrated an economic method with the synthesis of 2-tetralyl carboxylic esters, a valuable class of bioactive compounds.