Selective, radical-free activation of benzylic C–H bonds in methylarenes

Abstract

We report rare examples of exclusive benzylic C–H oxidative addition in industrially important methylarenes using simple η⁴-arene iridium complexes. Mechanistic studies showed that coordinatively unsaturated η²-arene intermediates are responsible for the selective activation of benzylic, not aromatic C–H bonds and formation of stable benzyl complexes after trapping with a phosphine ligand.