Iridium and rhodium complexes bearing a silyl-bipyridine pincer ligand: synthesis, structures and catalytic activity for C-H borylation of arenes

Unsaturated 16-electron iridium and rhodium complexes bearing a silyl-bipyridine-based SiNN-pincer ligand (Bpy SiNN ) were synthesised and characterised by X-ray crystallography and NMR spectroscopy. The iridium-Bpy SiNN complex facilitated the catalytic C(sp 2 )-H borylation of arenes to give arylboronate esters in high yields (≥93%) under mild conditions (∼40 °C). The synthesis of five-coordinate 16e SiNN-pincer complexes of iridium and rhodium, and catalytic C(sp 2 )-H borylation under mild conditions are described.