Air‐Stable Bis‐Cyclometallated Iridium Catalysts for Ortho‐Directed C(sp2)−H Borylation.

We report a class of isolable bis‐cyclometallated iridium precatalysts (ImIr) and their use in regioselective ortho−C−H borylation of aromatic, heteroaromatic, acrylic, and aliphatic systems. The catalysts consist of two imine ligands and an acetate coordinated to an iridium (III) center. The isolable character of ImIr warrants its compatibility with high‐throughput experimentation, a prerequisite for applications in late‐stage functionalization (LSF) of complex substrates. Initial mechanistic studies point towards an inner‐sphere mechanism involving bis‐cyclometallated species shedding light on the general mechanistic understanding of ortho‐selective C−H borylations. [ABSTRACT FROM AUTHOR]