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

We report rare examples of exclusive benzylic C-H oxidative addition in industrially important methylarenes using simple eta(4)-arene iridium complexes. Mechanistic studies showed that coordinatively unsaturated eta(2)-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.