Palladium-Catalyzed Amination of Aromatic C–H Bonds with Oxime Esters

We report a conceptually new approach to the direct amination of aromatic C−H bonds. In this process, an oxime ester function reacts with an aromatic C−H bond under redox-neutral conditions to form, in the case studied, an indole product. These reactions occur with relatively low catalyst loading (1 mol %) by a mechanism that appears to involve an unusual initial oxidative addition of an N−O bond to a Pd(0) species. The Pd(II) complex from oxidative addition of the N−X bond has been isolated for the first time, and evidence for the intermediacy of such oxidative addition products in the catalytic reaction has been gained. Read more on publisher's site.