Iridium-Catalyzed Silylation of Aryl C–H Bonds

A method for the iridium-catalyzed silylation of aryl C-H bonds is described. The reaction of HSiMe(OSiMe3)2 with arenes and heteroarenes catalyzed by the combination of Ir(cod)(OMe)2 and 2,4,7-trimethylphenanthroline occurs with the aromatic compound as the limiting reagent and with high levels of sterically derived regioselectivity. This new catalytic system occurs with a much higher tolerance for functional groups than the previously reported rhodium-catalyzed silylation of aryl C-H bonds and occurs with a wide range of heteroarenes. The silylarene products are suitable for further transformations, such as oxidation, halogenation, and cross-coupling. Late-stage functionalization of complex pharmaceutical compounds was demonstrated.