Palladium-Catalyzed Direct C-H Arylation of Arenes Promoted by Quaternary Ammonium Salt

Abstract

A new Pd-based catalytic system for the direct C-H arylation of arenes was developed. The use of a substoichiometric amount of quaternary ammonium salt as an additive with a Pd source achieved the direct arylation of unactivated arenes under milder reaction conditions in moderate to high yields. The ammonium salt generates the anionic palladium complex, thereby facilitating arylation by a concerted metalation-deprotonation process.