Fig. 4: Proposed mechanism of cascade C(sp2) & C(sp3)–H activation.

Arylpalladium (A), intermediate (B), aryl-norbornyl-palladacycle (ANP) (C), Pd(IV) intermediate (D), ortho-alkylated intermediate (E), intermediate (F), transient secondary alkylpalladium (G), transient secondary alkylpalladium (H), six-membered palladacycle (I). OA oxidative addition, RE reductive elimination.