Palladium-Catalyzed [3 + 2] Annulation of o‑Bromobenzyl Cyanide with Norbornene Derivatives via C(sp3)–H Bond Activation to Yield 1‑Cyanoindane

A novel [3 + 2] annulation of arylacetonitrile with norbornene derivatives to form 1-cyanoindane derivatives has been established. The 2-fold C–C bond was generated, and then the 1-cyanoindane skeleton was established via Pd(OAc)2/DPEPhos-catalyzed C(sp3)–H activation of benzyl. The protocol is successfully realized, utilizing K3PO4 as the base and CH3CN as the solvent, in the presence of HFIP as an indispensable additive under mild reaction conditions.