Eric McNeill and Justin Du Bois Chemical Science
Transition metal-catalysed methods for the chemoselective oxidation of C-H bonds have been widely developed over the past 15 years. DuBois and co-workers report a new ruthenium-based catalyst for carrying out teriary and benzylic C-H oxidations. Previous work in this area has focused on developing precatalysts that generate the active ruthenium tetroxide in situ. However, the group have taken a different approach, introducing a tridentate Me3tacn ligand to the precatalyst and generating a cis-dioxoruthenium catalytic species.
The catalyst carries out C-H oxidations selectively in a number of polyfunctional molecules at the most electron rich tertiary or benzylic C-H bond. Interestingly, the group observed that this catalytic system is more efficient than a system generating ruthenium tetroxide.
Moreover, introducing a ligand system to ruthenium-mediated oxidations raises the possibility of ligand design optimising for chemoselectivity or perhaps stereoselectivity.